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diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..6833f05 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,3 @@ +* text=auto +*.txt text +*.md text diff --git a/1705-h.zip b/1705-h.zip Binary files differnew file mode 100644 index 0000000..c8c51cd --- /dev/null +++ b/1705-h.zip diff --git a/1705-h/1705-h.htm b/1705-h/1705-h.htm new file mode 100644 index 0000000..2d00300 --- /dev/null +++ b/1705-h/1705-h.htm @@ -0,0 +1,9438 @@ +<?xml version="1.0" encoding="us-ascii"?> + +<!DOCTYPE html + PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd" > + +<html xmlns="http://www.w3.org/1999/xhtml" lang="en"> + <head> + <title> + A History of Science, Vol I. by Henry Smith Williams + </title> + <style type="text/css" xml:space="preserve"> + + body { margin:5%; background:#faebd0; text-align:justify} + P { text-indent: 1em; margin-top: .25em; margin-bottom: .25em; } + H1,H2,H3,H4,H5,H6 { text-align: center; margin-left: 15%; margin-right: 15%; } + hr { width: 50%; text-align: center;} + .foot { margin-left: 20%; margin-right: 20%; text-align: justify; text-indent: -3em; font-size: 90%; } + blockquote {font-size: 97%; font-style: italic; margin-left: 10%; margin-right: 10%;} + .mynote {background-color: #DDE; color: #000; padding: .5em; margin-left: 10%; margin-right: 10%; font-family: sans-serif; font-size: 95%;} + .toc { margin-left: 10%; margin-bottom: .75em;} + .toc2 { margin-left: 20%;} + div.fig { display:block; margin:0 auto; text-align:center; } + div.middle { margin-left: 20%; margin-right: 20%; text-align: justify; } + .figleft {float: left; margin-left: 0%; margin-right: 1%;} + .figright {float: right; margin-right: 0%; margin-left: 1%;} + .pagenum {display:inline; font-size: 70%; font-style:normal; + margin: 0; padding: 0; position: absolute; right: 1%; + text-align: right;} + pre { font-style: italic; font-size: 90%; margin-left: 10%;} + +</style> + </head> + <body> +<pre xml:space="preserve"> + +The Project Gutenberg EBook of A History of Science, Volume 1(of 5), by +Henry Smith Williams + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: A History of Science, Volume 1(of 5) + +Author: Henry Smith Williams + +Release Date: November 17, 2009 [EBook #1705] +Last Updated: January 26, 2013 + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK HISTORY OF SCIENCE, V1 *** + + + + +Produced by Charles Keller, and David Widger + + + + + + +</pre> + <p> + <br /><br /> + </p> + <h1> + A HISTORY OF SCIENCE + </h1> + <h2> + BY HENRY SMITH WILLIAMS, M.D., LL.D. <br /> <br /> <br /> ASSISTED BY EDWARD + H. WILLIAMS, M.D. <br /> <br /><br /> IN FIVE VOLUMES <br /> <br /> VOLUME I. + THE BEGINNINGS OF SCIENCE + </h2> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> + </p> + <blockquote> + <p class="toc"> + <big><b>CONTENTS</b></big> + </p> + <p> + <br /> <a href="#link2H_4_0001"> <b>A HISTORY OF SCIENCE</b> </a><br /> + <br /><br /> <a href="#link2H_4_0002"> <b>BOOK I</b> </a><br /><br /> + </p> + <p class="toc"> + <a href="#link2H_4_0003"> I. PREHISTORIC SCIENCE </a> + </p> + <p class="toc"> + <a href="#link2H_4_0004"> II. EGYPTIAN SCIENCE </a> + </p> + <p class="toc"> + <a href="#link2H_4_0005"> III. SCIENCE OF BABYLONIA AND ASSYRIA </a> + </p> + <p class="toc"> + <a href="#link2H_4_0006"> IV. THE DEVELOPMENT OF THE ALPHABET </a> + </p> + <p class="toc"> + <a href="#link2H_4_0007"> V. THE BEGINNINGS OF GREEK SCIENCE </a> + </p> + <p class="toc"> + <a href="#link2H_4_0008"> VI. THE EARLY GREEK PHILOSOPHERS IN ITALY </a> + </p> + <p class="toc"> + <a href="#link2H_4_0009"> VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + </a> + </p> + <p class="toc"> + <a href="#link2H_4_0010"> VIII. POST-SOCRATIC SCIENCE AT ATHENS—PLATO, + ARISTOTLE, AND THEOPHRASTUS </a> + </p> + <p class="toc"> + <a href="#link2H_4_0011"> IX. GREEK SCIENCE OF THE ALEXANDRIAN OR + HELLENISTIC PERIOD </a> + </p> + <p class="toc"> + <a href="#link2H_4_0012"> X. SCIENCE OF THE ROMAN PERIOD </a> + </p> + <p class="toc"> + <a href="#link2H_4_0013"> XI. A RETROSPECTIVE GLANCE AT CLASSICAL + SCIENCE </a> + </p> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> + </p> + <p class="toc2"> + <a href="#link2H_APPE"> <b>APPENDIX</b> </a> + </p> + <p class="toc2"> + <a href="#link2HCH0001"> CHAPTER I. PREHISTORIC SCIENCE </a> + </p> + <p class="toc2"> + <a href="#link2HCH0002"> CHAPTER II. EGYPTIAN SCIENCE </a> + </p> + <p class="toc2"> + <a href="#link2HCH0003"> CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + </a> + </p> + <p class="toc2"> + <a href="#link2HCH0004"> CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + </a> + </p> + <p class="toc2"> + <a href="#link2HCH0005"> CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE </a> + </p> + <p class="toc2"> + <a href="#link2HCH0006"> CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN + ITALY </a> + </p> + <p class="toc2"> + <a href="#link2HCH0007"> CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC + PERIOD </a> + </p> + <p class="toc2"> + <a href="#link2HCH0008"> CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + </a> + </p> + <p class="toc2"> + <a href="#link2HCH0009"> CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR + HELLENISTIC PERIOD </a> + </p> + <p class="toc2"> + <a href="#link2HCH0010"> CHAPTER X. SCIENCE OF THE ROMAN PERIOD </a> + </p> + <p class="toc2"> + <a href="#link2HCH0011"> CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL + SCIENCE </a> + </p> + </blockquote> + <p> + <a name="link2H_4_0001" id="link2H_4_0001"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h1> + A HISTORY OF SCIENCE + </h1> + <p> + <a name="link2H_4_0002" id="link2H_4_0002"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + BOOK I + </h2> + <p> + Should the story that is about to be unfolded be found to lack interest, + the writers must stand convicted of unpardonable lack of art. Nothing but + dulness in the telling could mar the story, for in itself it is the record + of the growth of those ideas that have made our race and its civilization + what they are; of ideas instinct with human interest, vital with meaning + for our race; fundamental in their influence on human development; part + and parcel of the mechanism of human thought on the one hand, and of + practical civilization on the other. Such a phrase as "fundamental + principles" may seem at first thought a hard saying, but the idea it + implies is less repellent than the phrase itself, for the fundamental + principles in question are so closely linked with the present interests of + every one of us that they lie within the grasp of every average man and + woman—nay, of every well-developed boy and girl. These principles + are not merely the stepping-stones to culture, the prerequisites of + knowledge—they are, in themselves, an essential part of the + knowledge of every cultivated person. + </p> + <p> + It is our task, not merely to show what these principles are, but to point + out how they have been discovered by our predecessors. We shall trace the + growth of these ideas from their first vague beginnings. We shall see how + vagueness of thought gave way to precision; how a general truth, once + grasped and formulated, was found to be a stepping-stone to other truths. + We shall see that there are no isolated facts, no isolated principles, in + nature; that each part of our story is linked by indissoluble bands with + that which goes before, and with that which comes after. For the most part + the discovery of this principle or that in a given sequence is no + accident. Galileo and Keppler must precede Newton. Cuvier and Lyall must + come before Darwin;—Which, after all, is no more than saying that in + our Temple of Science, as in any other piece of architecture, the + foundation must precede the superstructure. + </p> + <p> + We shall best understand our story of the growth of science if we think of + each new principle as a stepping-stone which must fit into its own + particular niche; and if we reflect that the entire structure of modern + civilization would be different from what it is, and less perfect than it + is, had not that particular stepping-stone been found and shaped and + placed in position. Taken as a whole, our stepping-stones lead us up and + up towards the alluring heights of an acropolis of knowledge, on which + stands the Temple of Modern Science. The story of the building of this + wonderful structure is in itself fascinating and beautiful. + </p> + <p> + <a name="link2H_4_0003" id="link2H_4_0003"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + I. PREHISTORIC SCIENCE + </h2> + <p> + To speak of a prehistoric science may seem like a contradiction of terms. + The word prehistoric seems to imply barbarism, while science, clearly + enough, seems the outgrowth of civilization; but rightly considered, there + is no contradiction. For, on the one hand, man had ceased to be a + barbarian long before the beginning of what we call the historical period; + and, on the other hand, science, of a kind, is no less a precursor and a + cause of civilization than it is a consequent. To get this clearly in + mind, we must ask ourselves: What, then, is science? The word runs glibly + enough upon the tongue of our every-day speech, but it is not often, + perhaps, that they who use it habitually ask themselves just what it + means. Yet the answer is not difficult. A little attention will show that + science, as the word is commonly used, implies these things: first, the + gathering of knowledge through observation; second, the classification of + such knowledge, and through this classification, the elaboration of + general ideas or principles. In the familiar definition of Herbert + Spencer, science is organized knowledge. + </p> + <p> + Now it is patent enough, at first glance, that the veriest savage must + have been an observer of the phenomena of nature. But it may not be so + obvious that he must also have been a classifier of his observations—an + organizer of knowledge. Yet the more we consider the case, the more clear + it will become that the two methods are too closely linked together to be + dissevered. To observe outside phenomena is not more inherent in the + nature of the mind than to draw inferences from these phenomena. A deer + passing through the forest scents the ground and detects a certain odor. A + sequence of ideas is generated in the mind of the deer. Nothing in the + deer's experience can produce that odor but a wolf; therefore the + scientific inference is drawn that wolves have passed that way. But it is + a part of the deer's scientific knowledge, based on previous experience, + individual and racial; that wolves are dangerous beasts, and so, combining + direct observation in the present with the application of a general + principle based on past experience, the deer reaches the very logical + conclusion that it may wisely turn about and run in another direction. All + this implies, essentially, a comprehension and use of scientific + principles; and, strange as it seems to speak of a deer as possessing + scientific knowledge, yet there is really no absurdity in the statement. + The deer does possess scientific knowledge; knowledge differing in degree + only, not in kind, from the knowledge of a Newton. Nor is the animal, + within the range of its intelligence, less logical, less scientific in the + application of that knowledge, than is the man. The animal that could not + make accurate scientific observations of its surroundings, and deduce + accurate scientific conclusions from them, would soon pay the penalty of + its lack of logic. + </p> + <p> + What is true of man's precursors in the animal scale is, of course, true + in a wider and fuller sense of man himself at the very lowest stage of his + development. Ages before the time which the limitations of our knowledge + force us to speak of as the dawn of history, man had reached a high stage + of development. As a social being, he had developed all the elements of a + primitive civilization. If, for convenience of classification, we speak of + his state as savage, or barbaric, we use terms which, after all, are + relative, and which do not shut off our primitive ancestors from a + tolerably close association with our own ideals. We know that, even in the + Stone Age, man had learned how to domesticate animals and make them useful + to him, and that he had also learned to cultivate the soil. Later on, + doubtless by slow and painful stages, he attained those wonderful elements + of knowledge that enabled him to smelt metals and to produce implements of + bronze, and then of iron. Even in the Stone Age he was a mechanic of + marvellous skill, as any one of to-day may satisfy himself by attempting + to duplicate such an implement as a chipped arrow-head. And a barbarian + who could fashion an axe or a knife of bronze had certainly gone far in + his knowledge of scientific principles and their practical application. + The practical application was, doubtless, the only thought that our + primitive ancestor had in mind; quite probably the question as to + principles that might be involved troubled him not at all. Yet, in spite + of himself, he knew certain rudimentary principles of science, even though + he did not formulate them. + </p> + <p> + Let us inquire what some of these principles are. Such an inquiry will, as + it were, clear the ground for our structure of science. It will show the + plane of knowledge on which historical investigation begins. Incidentally, + perhaps, it will reveal to us unsuspected affinities between ourselves and + our remote ancestor. Without attempting anything like a full analysis, we + may note in passing, not merely what primitive man knew, but what he did + not know; that at least a vague notion may be gained of the field for + scientific research that lay open for historic man to cultivate. + </p> + <p> + It must be understood that the knowledge of primitive man, as we are about + to outline it, is inferential. We cannot trace the development of these + principles, much less can we say who discovered them. Some of them, as + already suggested, are man's heritage from non-human ancestors. Others can + only have been grasped by him after he had reached a relatively high stage + of human development. But all the principles here listed must surely have + been parts of our primitive ancestor's knowledge before those earliest + days of Egyptian and Babylonian civilization, the records of which + constitute our first introduction to the so-called historical period. + Taken somewhat in the order of their probable discovery, the scientific + ideas of primitive man may be roughly listed as follows: + </p> + <p> + 1. Primitive man must have conceived that the earth is flat and of + limitless extent. By this it is not meant to imply that he had a distinct + conception of infinity, but, for that matter, it cannot be said that any + one to-day has a conception of infinity that could be called definite. + But, reasoning from experience and the reports of travellers, there was + nothing to suggest to early man the limit of the earth. He did, indeed, + find in his wanderings, that changed climatic conditions barred him from + farther progress; but beyond the farthest reaches of his migrations, the + seemingly flat land-surfaces and water-surfaces stretched away unbroken + and, to all appearances, without end. It would require a reach of the + philosophical imagination to conceive a limit to the earth, and while such + imaginings may have been current in the prehistoric period, we can have no + proof of them, and we may well postpone consideration of man's early + dreamings as to the shape of the earth until we enter the historical epoch + where we stand on firm ground. + </p> + <p> + 2. Primitive man must, from a very early period, have observed that the + sun gives heat and light, and that the moon and stars seem to give light + only and no heat. It required but a slight extension of this observation + to note that the changing phases of the seasons were associated with the + seeming approach and recession of the sun. This observation, however, + could not have been made until man had migrated from the tropical regions, + and had reached a stage of mechanical development enabling him to live in + subtropical or temperate zones. Even then it is conceivable that a long + period must have elapsed before a direct causal relation was felt to exist + between the shifting of the sun and the shifting of the seasons; because, + as every one knows, the periods of greatest heat in summer and greatest + cold in winter usually come some weeks after the time of the solstices. + Yet, the fact that these extremes of temperature are associated in some + way with the change of the sun's place in the heavens must, in time, have + impressed itself upon even a rudimentary intelligence. It is hardly + necessary to add that this is not meant to imply any definite knowledge of + the real meaning of, the seeming oscillations of the sun. We shall see + that, even at a relatively late period, the vaguest notions were still in + vogue as to the cause of the sun's changes of position. + </p> + <p> + That the sun, moon, and stars move across the heavens must obviously have + been among the earliest scientific observations. It must not be inferred, + however, that this observation implied a necessary conception of the + complete revolution of these bodies about the earth. It is unnecessary to + speculate here as to how the primitive intelligence conceived the transfer + of the sun from the western to the eastern horizon, to be effected each + night, for we shall have occasion to examine some historical speculations + regarding this phenomenon. We may assume, however, that the idea of the + transfer of the heavenly bodies beneath the earth (whatever the conception + as to the form of that body) must early have presented itself. + </p> + <p> + It required a relatively high development of the observing faculties, yet + a development which man must have attained ages before the historical + period, to note that the moon has a secondary motion, which leads it to + shift its relative position in the heavens, as regards the stars; that the + stars themselves, on the other hand, keep a fixed relation as regards one + another, with the notable exception of two or three of the most brilliant + members of the galaxy, the latter being the bodies which came to be known + finally as planets, or wandering stars. The wandering propensities of such + brilliant bodies as Jupiter and Venus cannot well have escaped detection. + We may safely assume, however, that these anomalous motions of the moon + and planets found no explanation that could be called scientific until a + relatively late period. + </p> + <p> + 3. Turning from the heavens to the earth, and ignoring such primitive + observations as that of the distinction between land and water, we may + note that there was one great scientific law which must have forced itself + upon the attention of primitive man. This is the law of universal + terrestrial gravitation. The word gravitation suggests the name of Newton, + and it may excite surprise to hear a knowledge of gravitation ascribed to + men who preceded that philosopher by, say, twenty-five or fifty thousand + years. Yet the slightest consideration of the facts will make it clear + that the great central law that all heavy bodies fall directly towards the + earth, cannot have escaped the attention of the most primitive + intelligence. The arboreal habits of our primitive ancestors gave + opportunities for constant observation of the practicalities of this law. + And, so soon as man had developed the mental capacity to formulate ideas, + one of the earliest ideas must have been the conception, however vaguely + phrased in words, that all unsupported bodies fall towards the earth. The + same phenomenon being observed to operate on water-surfaces, and no + alteration being observed in its operation in different portions of man's + habitat, the most primitive wanderer must have come to have full faith in + the universal action of the observed law of gravitation. Indeed, it is + inconceivable that he can have imagined a place on the earth where this + law does not operate. On the other hand, of course, he never grasped the + conception of the operation of this law beyond the close proximity of the + earth. To extend the reach of gravitation out to the moon and to the + stars, including within its compass every particle of matter in the + universe, was the work of Newton, as we shall see in due course. Meantime + we shall better understand that work if we recall that the mere local fact + of terrestrial gravitation has been the familiar knowledge of all + generations of men. It may further help to connect us in sympathy with our + primeval ancestor if we recall that in the attempt to explain this fact of + terrestrial gravitation Newton made no advance, and we of to-day are + scarcely more enlightened than the man of the Stone Age. Like the man of + the Stone Age, we know that an arrow shot into the sky falls back to the + earth. We can calculate, as he could not do, the arc it will describe and + the exact speed of its fall; but as to why it returns to earth at all, the + greatest philosopher of to-day is almost as much in the dark as was the + first primitive bowman that ever made the experiment. + </p> + <p> + Other physical facts going to make up an elementary science of mechanics, + that were demonstratively known to prehistoric man, were such as these: + the rigidity of solids and the mobility of liquids; the fact that changes + of temperature transform solids to liquids and vice versa—that heat, + for example, melts copper and even iron, and that cold congeals water; and + the fact that friction, as illustrated in the rubbing together of two + sticks, may produce heat enough to cause a fire. The rationale of this + last experiment did not receive an explanation until about the beginning + of the nineteenth century of our own era. But the experimental fact was so + well known to prehistoric man that he employed this method, as various + savage tribes employ it to this day, for the altogether practical purpose + of making a fire; just as he employed his practical knowledge of the + mutability of solids and liquids in smelting ores, in alloying copper with + tin to make bronze, and in casting this alloy in molds to make various + implements and weapons. Here, then, were the germs of an elementary + science of physics. Meanwhile such observations as that of the solution of + salt in water may be considered as giving a first lesson in chemistry, but + beyond such altogether rudimentary conceptions chemical knowledge could + not have gone—unless, indeed, the practical observation of the + effects of fire be included; nor can this well be overlooked, since + scarcely another single line of practical observation had a more direct + influence in promoting the progress of man towards the heights of + civilization. + </p> + <p> + 4. In the field of what we now speak of as biological knowledge, primitive + man had obviously the widest opportunity for practical observation. We can + hardly doubt that man attained, at an early day, to that conception of + identity and of difference which Plato places at the head of his + metaphysical system. We shall urge presently that it is precisely such + general ideas as these that were man's earliest inductions from + observation, and hence that came to seem the most universal and "innate" + ideas of his mentality. It is quite inconceivable, for example, that even + the most rudimentary intelligence that could be called human could fail to + discriminate between living things and, let us say, the rocks of the + earth. The most primitive intelligence, then, must have made a tacit + classification of the natural objects about it into the grand divisions of + animate and inanimate nature. Doubtless the nascent scientist may have + imagined life animating many bodies that we should call inanimate—such + as the sun, wandering planets, the winds, and lightning; and, on the other + hand, he may quite likely have relegated such objects as trees to the + ranks of the non-living; but that he recognized a fundamental distinction + between, let us say, a wolf and a granite bowlder we cannot well doubt. A + step beyond this—a step, however, that may have required centuries + or millenniums in the taking—must have carried man to a plane of + intelligence from which a primitive Aristotle or Linnaeus was enabled to + note differences and resemblances connoting such groups of things as + fishes, birds, and furry beasts. This conception, to be sure, is an + abstraction of a relatively high order. We know that there are savage + races to-day whose language contains no word for such an abstraction as + bird or tree. We are bound to believe, then, that there were long ages of + human progress during which the highest man had attained no such stage of + abstraction; but, on the other hand, it is equally little in question that + this degree of mental development had been attained long before the + opening of our historical period. The primeval man, then, whose scientific + knowledge we are attempting to predicate, had become, through his + conception of fishes, birds, and hairy animals as separate classes, a + scientific zoologist of relatively high attainments. + </p> + <p> + In the practical field of medical knowledge, a certain stage of + development must have been reached at a very early day. Even animals pick + and choose among the vegetables about them, and at times seek out certain + herbs quite different from their ordinary food, practising a sort of + instinctive therapeutics. The cat's fondness for catnip is a case in + point. The most primitive man, then, must have inherited a racial or + instinctive knowledge of the medicinal effects of certain herbs; in + particular he must have had such elementary knowledge of toxicology as + would enable him to avoid eating certain poisonous berries. Perhaps, + indeed, we are placing the effect before the cause to some extent; for, + after all, the animal system possesses marvellous powers of adaption, and + there is perhaps hardly any poisonous vegetable which man might not have + learned to eat without deleterious effect, provided the experiment were + made gradually. To a certain extent, then, the observed poisonous effects + of numerous plants upon the human system are to be explained by the fact + that our ancestors have avoided this particular vegetable. Certain fruits + and berries might have come to have been a part of man's diet, had they + grown in the regions he inhabited at an early day, which now are poisonous + to his system. This thought, however, carries us too far afield. For + practical purposes, it suffices that certain roots, leaves, and fruits + possess principles that are poisonous to the human system, and that unless + man had learned in some way to avoid these, our race must have come to + disaster. In point of fact, he did learn to avoid them; and such evidence + implied, as has been said, an elementary knowledge of toxicology. + </p> + <p> + Coupled with this knowledge of things dangerous to the human system, there + must have grown up, at a very early day, a belief in the remedial + character of various vegetables as agents to combat disease. Here, of + course, was a rudimentary therapeutics, a crude principle of an empirical + art of medicine. As just suggested, the lower order of animals have an + instinctive knowledge that enables them to seek out remedial herbs (though + we probably exaggerate the extent of this instinctive knowledge); and if + this be true, man must have inherited from his prehuman ancestors this + instinct along with the others. That he extended this knowledge through + observation and practice, and came early to make extensive use of drugs in + the treatment of disease, is placed beyond cavil through the observation + of the various existing barbaric tribes, nearly all of whom practice + elaborate systems of therapeutics. We shall have occasion to see that even + within historic times the particular therapeutic measures employed were + often crude, and, as we are accustomed to say, unscientific; but even the + crudest of them are really based upon scientific principles, inasmuch as + their application implies the deduction of principles of action from + previous observations. Certain drugs are applied to appease certain + symptoms of disease because in the belief of the medicine-man such drugs + have proved beneficial in previous similar cases. + </p> + <p> + All this, however, implies an appreciation of the fact that man is subject + to "natural" diseases, and that if these diseases are not combated, death + may result. But it should be understood that the earliest man probably had + no such conception as this. Throughout all the ages of early development, + what we call "natural" disease and "natural" death meant the onslaught of + a tangible enemy. A study of this question leads us to some very curious + inferences. The more we look into the matter the more the thought forces + itself home to us that the idea of natural death, as we now conceive it, + came to primitive man as a relatively late scientific induction. This + thought seems almost startling, so axiomatic has the conception "man is + mortal" come to appear. Yet a study of the ideas of existing savages, + combined with our knowledge of the point of view from which historical + peoples regard disease, make it more probable that the primitive + conception of human life did not include the idea of necessary death. We + are told that the Australian savage who falls from a tree and breaks his + neck is not regarded as having met a natural death, but as having been the + victim of the magical practices of the "medicine-man" of some neighboring + tribe. Similarly, we shall find that the Egyptian and the Babylonian of + the early historical period conceived illness as being almost invariably + the result of the machinations of an enemy. One need but recall the + superstitious observances of the Middle Ages, and the yet more recent + belief in witchcraft, to realize how generally disease has been + personified as a malicious agent invoked by an unfriendly mind. Indeed, + the phraseology of our present-day speech is still reminiscent of this; as + when, for example, we speak of an "attack of fever," and the like. + </p> + <p> + When, following out this idea, we picture to ourselves the conditions + under which primitive man lived, it will be evident at once how relatively + infrequent must have been his observation of what we usually term natural + death. His world was a world of strife; he lived by the chase; he saw + animals kill one another; he witnessed the death of his own fellows at the + hands of enemies. Naturally enough, then, when a member of his family was + "struck down" by invisible agents, he ascribed this death also to + violence, even though the offensive agent was concealed. Moreover, having + very little idea of the lapse of time—being quite unaccustomed, that + is, to reckon events from any fixed era—primitive man cannot have + gained at once a clear conception of age as applied to his fellows. Until + a relatively late stage of development made tribal life possible, it + cannot have been usual for man to have knowledge of his grandparents; as a + rule he did not know his own parents after he had passed the adolescent + stage and had been turned out upon the world to care for himself. If, + then, certain of his fellow-beings showed those evidences of infirmity + which we ascribe to age, it did not necessarily follow that he saw any + association between such infirmities and the length of time which those + persons had lived. The very fact that some barbaric nations retain the + custom of killing the aged and infirm, in itself suggests the possibility + that this custom arose before a clear conception had been attained that + such drags upon the community would be removed presently in the natural + order of things. To a person who had no clear conception of the lapse of + time and no preconception as to the limited period of man's life, the + infirmities of age might very naturally be ascribed to the repeated + attacks of those inimical powers which were understood sooner or later to + carry off most members of the race. And coupled with this thought would go + the conception that inasmuch as some people through luck had escaped the + vengeance of all their enemies for long periods, these same individuals + might continue to escape for indefinite periods of the future. There were + no written records to tell primeval man of events of long ago. He lived in + the present, and his sweep of ideas scarcely carried him back beyond the + limits of his individual memory. But memory is observed to be fallacious. + It must early have been noted that some people recalled events which other + participants in them had quite forgotten, and it may readily enough have + been inferred that those members of the tribe who spoke of events which + others could not recall were merely the ones who were gifted with the best + memories. If these reached a period when their memories became vague, it + did not follow that their recollections had carried them back to the + beginnings of their lives. Indeed, it is contrary to all experience to + believe that any man remembers all the things he has once known, and the + observed fallaciousness and evanescence of memory would thus tend to + substantiate rather than to controvert the idea that various members of a + tribe had been alive for an indefinite period. + </p> + <p> + Without further elaborating the argument, it seems a justifiable inference + that the first conception primitive man would have of his own life would + not include the thought of natural death, but would, conversely, connote + the vague conception of endless life. Our own ancestors, a few generations + removed, had not got rid of this conception, as the perpetual quest of the + spring of eternal youth amply testifies. A naturalist of our own day has + suggested that perhaps birds never die except by violence. The thought, + then, that man has a term of years beyond which "in the nature of things," + as the saying goes, he may not live, would have dawned but gradually upon + the developing intelligence of successive generations of men; and we + cannot feel sure that he would fully have grasped the conception of a + "natural" termination of human life until he had shaken himself free from + the idea that disease is always the result of the magic practice of an + enemy. Our observation of historical man in antiquity makes it somewhat + doubtful whether this conception had been attained before the close of the + prehistoric period. If it had, this conception of the mortality of man was + one of the most striking scientific inductions to which prehistoric man + attained. Incidentally, it may be noted that the conception of eternal + life for the human body being a more primitive idea than the conception of + natural death, the idea of the immortality of the spirit would be the most + natural of conceptions. The immortal spirit, indeed, would be but a + correlative of the immortal body, and the idea which we shall see + prevalent among the Egyptians that the soul persists only as long as the + body is intact—the idea upon which the practice of mummifying the + dead depended—finds a ready explanation. But this phase of the + subject carries us somewhat afield. For our present purpose it suffices to + have pointed out that the conception of man's mortality—a conception + which now seems of all others the most natural and "innate"—was in + all probability a relatively late scientific induction of our primitive + ancestors. + </p> + <p> + 5. Turning from the consideration of the body to its mental complement, we + are forced to admit that here, also, our primitive man must have made + certain elementary observations that underlie such sciences as psychology, + mathematics, and political economy. The elementary emotions associated + with hunger and with satiety, with love and with hatred, must have forced + themselves upon the earliest intelligence that reached the plane of + conscious self-observation. The capacity to count, at least to the number + four or five, is within the range of even animal intelligence. Certain + savages have gone scarcely farther than this; but our primeval ancestor, + who was forging on towards civilization, had learned to count his fingers + and toes, and to number objects about him by fives and tens in + consequence, before he passed beyond the plane of numerous existing + barbarians. How much beyond this he had gone we need not attempt to + inquire; but the relatively high development of mathematics in the early + historical period suggests that primeval man had attained a not + inconsiderable knowledge of numbers. The humdrum vocation of looking after + a numerous progeny must have taught the mother the rudiments of addition + and subtraction; and the elements of multiplication and division are + implied in the capacity to carry on even the rudest form of barter, such + as the various tribes must have practised from an early day. + </p> + <p> + As to political ideas, even the crudest tribal life was based on certain + conceptions of ownership, at least of tribal ownership, and the + application of the principle of likeness and difference to which we have + already referred. Each tribe, of course, differed in some regard from + other tribes, and the recognition of these differences implied in itself a + political classification. A certain tribe took possession of a particular + hunting-ground, which became, for the time being, its home, and over which + it came to exercise certain rights. An invasion of this territory by + another tribe might lead to war, and the banding together of the members + of the tribe to repel the invader implied both a recognition of communal + unity and a species of prejudice in favor of that community that + constituted a primitive patriotism. But this unity of action in opposing + another tribe would not prevent a certain rivalry of interest between the + members of the same tribe, which would show itself more and more + prominently as the tribe increased in size. The association of two or more + persons implies, always, the ascendency of some and the subordination of + others. Leadership and subordination are necessary correlatives of + difference of physical and mental endowment, and rivalry between leaders + would inevitably lead to the formation of primitive political parties. + With the ultimate success and ascendency of one leader, who secures either + absolute power or power modified in accordance with the advice of + subordinate leaders, we have the germs of an elaborate political system—an + embryo science of government. + </p> + <p> + Meanwhile, the very existence of such a community implies the recognition + on the part of its members of certain individual rights, the recognition + of which is essential to communal harmony. The right of individual + ownership of the various articles and implements of every-day life must be + recognized, or all harmony would be at an end. Certain rules of justice—primitive + laws—must, by common consent, give protection to the weakest members + of the community. Here are the rudiments of a system of ethics. It may + seem anomalous to speak of this primitive morality, this early recognition + of the principles of right and wrong, as having any relation to science. + Yet, rightly considered, there is no incongruity in such a citation. There + cannot well be a doubt that the adoption of those broad principles of + right and wrong which underlie the entire structure of modern civilization + was due to scientific induction,—in other words, to the belief, + based on observation and experience, that the principles implied were + essential to communal progress. He who has scanned the pageant of history + knows how often these principles seem to be absent in the intercourse of + men and nations. Yet the ideal is always there as a standard by which all + deeds are judged. + </p> + <p> + It would appear, then, that the entire superstructure of later science had + its foundation in the knowledge and practice of prehistoric man. The + civilization of the historical period could not have advanced as it has + had there not been countless generations of culture back of it. The new + principles of science could not have been evolved had there not been great + basal principles which ages of unconscious experiment had impressed upon + the mind of our race. Due meed of praise must be given, then, to our + primitive ancestor for his scientific accomplishments; but justice demands + that we should look a little farther and consider the reverse side of the + picture. We have had to do, thus far, chiefly with the positive side of + accomplishment. We have pointed out what our primitive ancestor knew, + intimating, perhaps, the limitations of his knowledge; but we have had + little to say of one all-important feature of his scientific theorizing. + The feature in question is based on the highly scientific desire and + propensity to find explanations for the phenomena of nature. Without such + desire no progress could be made. It is, as we have seen, the generalizing + from experience that constitutes real scientific progress; and yet, just + as most other good things can be overdone, this scientific propensity may + be carried to a disastrous excess. + </p> + <p> + Primeval man did not escape this danger. He observed, he reasoned, he + found explanations; but he did not always discriminate as to the + logicality of his reasonings. He failed to recognize the limitations of + his knowledge. The observed uniformity in the sequence of certain events + impressed on his mind the idea of cause and effect. Proximate causes + known, he sought remoter causes; childlike, his inquiring mind was always + asking, Why? and, childlike, he demanded an explicit answer. If the forces + of nature seemed to combat him, if wind and rain opposed his progress and + thunder and lightning seemed to menace his existence, he was led + irrevocably to think of those human foes who warred with him, and to see, + back of the warfare of the elements, an inscrutable malevolent + intelligence which took this method to express its displeasure. But every + other line of scientific observation leads equally, following back a + sequence of events, to seemingly causeless beginnings. Modern science can + explain the lightning, as it can explain a great number of the mysteries + which the primeval intelligence could not penetrate. But the primordial + man could not wait for the revelations of scientific investigation: he + must vault at once to a final solution of all scientific problems. He + found his solution by peopling the world with invisible forces, + anthropomorphic in their conception, like himself in their thought and + action, differing only in the limitations of their powers. His own dream + existence gave him seeming proof of the existence of an alter ego, a + spiritual portion of himself that could dissever itself from his body and + wander at will; his scientific inductions seemed to tell him of a world of + invisible beings, capable of influencing him for good or ill. From the + scientific exercise of his faculties he evolved the all-encompassing + generalizations of invisible and all-powerful causes back of the phenomena + of nature. These generalizations, early developed and seemingly supported + by the observations of countless generations, came to be among the most + firmly established scientific inductions of our primeval ancestor. They + obtained a hold upon the mentality of our race that led subsequent + generations to think of them, sometimes to speak of them, as "innate" + ideas. The observations upon which they were based are now, for the most + part, susceptible of other interpretations; but the old interpretations + have precedent and prejudice back of them, and they represent ideas that + are more difficult than almost any others to eradicate. Always, and + everywhere, superstitions based upon unwarranted early scientific + deductions have been the most implacable foes to the progress of science. + Men have built systems of philosophy around their conception of + anthropomorphic deities; they have linked to these systems of philosophy + the allied conception of the immutability of man's spirit, and they have + asked that scientific progress should stop short at the brink of these + systems of philosophy and accept their dictates as final. Yet there is not + to-day in existence, and there never has been, one jot of scientific + evidence for the existence of these intangible anthropomorphic powers back + of nature that is not susceptible of scientific challenge and of more + logical interpretation. In despite of which the superstitious beliefs are + still as firmly fixed in the minds of a large majority of our race as they + were in the mind of our prehistoric ancestor. The fact of this baleful + heritage must not be forgotten in estimating the debt of gratitude which + historic man owes to his barbaric predecessor. + </p> + <p> + <a name="link2H_4_0004" id="link2H_4_0004"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + II. EGYPTIAN SCIENCE + </h2> + <p> + In the previous chapter we have purposely refrained from referring to any + particular tribe or race of historical man. Now, however, we are at the + beginnings of national existence, and we have to consider the + accomplishments of an individual race; or rather, perhaps, of two or more + races that occupied successively the same geographical territory. But even + now our studies must for a time remain very general; we shall see little + or nothing of the deeds of individual scientists in the course of our + study of Egyptian culture. We are still, it must be understood, at the + beginnings of history; indeed, we must first bridge over the gap from the + prehistoric before we may find ourselves fairly on the line of march of + historical science. + </p> + <p> + At the very outset we may well ask what constitutes the distinction + between prehistoric and historic epochs—a distinction which has been + constantly implied in much that we have said. The reply savors somewhat of + vagueness. It is a distinction having to do, not so much with facts of + human progress as with our interpretation of these facts. When we speak of + the dawn of history we must not be understood to imply that, at the period + in question, there was any sudden change in the intellectual status of the + human race or in the status of any individual tribe or nation of men. What + we mean is that modern knowledge has penetrated the mists of the past for + the period we term historical with something more of clearness and + precision than it has been able to bring to bear upon yet earlier periods. + New accessions of knowledge may thus shift from time to time the bounds of + the so-called historical period. The clearest illustration of this is + furnished by our interpretation of Egyptian history. Until recently the + biblical records of the Hebrew captivity or service, together with the + similar account of Josephus, furnished about all that was known of + Egyptian history even of so comparatively recent a time as that of Ramses + II. (fifteenth century B.C.), and from that period on there was almost a + complete gap until the story was taken up by the Greek historians + Herodotus and Diodorus. It is true that the king-lists of the Alexandrian + historian, Manetho, were all along accessible in somewhat garbled copies. + But at best they seemed to supply unintelligible lists of names and dates + which no one was disposed to take seriously. That they were, broadly + speaking, true historical records, and most important historical records + at that, was not recognized by modern scholars until fresh light had been + thrown on the subject from altogether new sources. + </p> + <p> + These new sources of knowledge of ancient history demand a moment's + consideration. They are all-important because they have been the means of + extending the historical period of Egyptian history (using the word + history in the way just explained) by three or four thousand years. As + just suggested, that historical period carried the scholarship of the + early nineteenth century scarcely beyond the fifteenth century B.C., but + to-day's vision extends with tolerable clearness to about the middle of + the fifth millennium B.C. This change has been brought about chiefly + through study of the Egyptian hieroglyphics. These hieroglyphics + constitute, as we now know, a highly developed system of writing; a system + that was practised for some thousands of years, but which fell utterly + into disuse in the later Roman period, and the knowledge of which passed + absolutely from the mind of man. For about two thousand years no one was + able to read, with any degree of explicitness, a single character of this + strange script, and the idea became prevalent that it did not constitute a + real system of writing, but only a more or less barbaric system of + religious symbolism. The falsity of this view was shown early in the + nineteenth century when Dr. Thomas Young was led, through study of the + famous trilingual inscription of the Rosetta stone, to make the first + successful attempt at clearing up the mysteries of the hieroglyphics. + </p> + <p> + This is not the place to tell the story of his fascinating discoveries and + those of his successors. That story belongs to nineteenth-century science, + not to the science of the Egyptians. Suffice it here that Young gained the + first clew to a few of the phonetic values of the Egyptian symbols, and + that the work of discovery was carried on and vastly extended by the + Frenchman Champollion, a little later, with the result that the firm + foundations of the modern science of Egyptology were laid. Subsequently + such students as Rosellini the Italian, Lepsius the German, and Wilkinson + the Englishman, entered the field, which in due course was cultivated by + De Rouge in France and Birch in England, and by such distinguished + latter-day workers as Chabas, Mariette, Maspero, Amelineau, and De Morgan + among the Frenchmen; Professor Petrie and Dr. Budge in England; and + Brugsch Pasha and Professor Erman in Germany, not to mention a large + coterie of somewhat less familiar names. These men working, some of them + in the field of practical exploration, some as students of the Egyptian + language and writing, have restored to us a tolerably precise knowledge of + the history of Egypt from the time of the first historical king, Mena, + whose date is placed at about the middle of the fifth century B.C. We know + not merely the names of most of the subsequent rulers, but some thing of + the deeds of many of them; and, what is vastly more important, we know, + thanks to the modern interpretation of the old literature, many things + concerning the life of the people, and in particular concerning their + highest culture, their methods of thought, and their scientific + attainments, which might well have been supposed to be past finding out. + Nor has modern investigation halted with the time of the first kings; the + recent explorations of such archaeologists as Amelineau, De Morgan, and + Petrie have brought to light numerous remains of what is now spoken of as + the predynastic period—a period when the inhabitants of the Nile + Valley used implements of chipped stone, when their pottery was made + without the use of the potter's wheel, and when they buried their dead in + curiously cramped attitudes without attempt at mummification. These + aboriginal inhabitants of Egypt cannot perhaps with strict propriety be + spoken of as living within the historical period, since we cannot date + their relics with any accuracy. But they give us glimpses of the early + stages of civilization upon which the Egyptians of the dynastic period + were to advance. + </p> + <p> + It is held that the nascent civilization of these Egyptians of the + Neolithic, or late Stone Age, was overthrown by the invading hosts of a + more highly civilized race which probably came from the East, and which + may have been of a Semitic stock. The presumption is that this invading + people brought with it a knowledge of the arts of war and peace, developed + or adopted in its old home. The introduction of these arts served to + bridge somewhat suddenly, so far as Egypt is concerned, that gap between + the prehistoric and the historic stage of culture to which we have all + along referred. The essential structure of that bridge, let it now be + clearly understood, consisted of a single element. That element is the + capacity to make written records: a knowledge of the art of writing. + Clearly understood, it is this element of knowledge that forms the line + bounding the historical period. Numberless mementos are in existence that + tell of the intellectual activities of prehistoric man; such mementos as + flint implements, pieces of pottery, and fragments of bone, inscribed with + pictures that may fairly be spoken of as works of art; but so long as no + written word accompanies these records, so long as no name of king or + scribe comes down to us, we feel that these records belong to the domain + of archaeology rather than to that of history. Yet it must be understood + all along that these two domains shade one into the other and, it has + already been urged, that the distinction between them is one that pertains + rather to modern scholarship than to the development of civilization + itself. Bearing this distinction still in mind, and recalling that the + historical period, which is to be the field of our observation throughout + the rest of our studies, extends for Egypt well back into the fifth + millennium B.C., let us briefly review the practical phases of that + civilization to which the Egyptian had attained before the beginning of + the dynastic period. Since theoretical science is everywhere linked with + the mechanical arts, this survey will give us a clear comprehension of the + field that lies open for the progress of science in the long stages of + historical time upon which we are just entering. + </p> + <p> + We may pass over such rudimentary advances in the direction of + civilization as are implied in the use of articulate language, the + application of fire to the uses of man, and the systematic making of + dwellings of one sort or another, since all of these are stages of + progress that were reached very early in the prehistoric period. What more + directly concerns us is to note that a really high stage of mechanical + development had been reached before the dawnings of Egyptian history + proper. All manner of household utensils were employed; the potter's wheel + aided in the construction of a great variety of earthen vessels; weaving + had become a fine art, and weapons of bronze, including axes, spears, + knives, and arrow-heads, were in constant use. Animals had long been + domesticated, in particular the dog, the cat, and the ox; the horse was + introduced later from the East. The practical arts of agriculture were + practised almost as they are at the present day in Egypt, there being, of + course, the same dependence then as now upon the inundations of the Nile. + </p> + <p> + As to government, the Egyptian of the first dynasty regarded his king as a + demi-god to be actually deified after his death, and this point of view + was not changed throughout the stages of later Egyptian history. In point + of art, marvellous advances upon the skill of the prehistoric man had been + made, probably in part under Asiatic influences, and that unique style of + stilted yet expressive drawing had come into vogue, which was to be + remembered in after times as typically Egyptian. More important than all + else, our Egyptian of the earliest historical period was in possession of + the art of writing. He had begun to make those specific records which were + impossible to the man of the Stone Age, and thus he had entered fully upon + the way of historical progress which, as already pointed out, has its very + foundation in written records. From now on the deeds of individual kings + could find specific record. It began to be possible to fix the chronology + of remote events with some accuracy; and with this same fixing of + chronologies came the advent of true history. The period which precedes + what is usually spoken of as the first dynasty in Egypt is one into which + the present-day searcher is still able to see but darkly. The evidence + seems to suggest than an invasion of relatively cultured people from the + East overthrew, and in time supplanted, the Neolithic civilization of the + Nile Valley. It is impossible to date this invasion accurately, but it + cannot well have been later than the year 5000 B.C., and it may have been + a great many centuries earlier than this. Be the exact dates what they + may, we find the Egyptian of the fifth millennium B.C. in full possession + of a highly organized civilization. + </p> + <p> + All subsequent ages have marvelled at the pyramids, some of which date + from about the year 4000 B.C., though we may note in passing that these + dates must not be taken too literally. The chronology of ancient Egypt + cannot as yet be fixed with exact accuracy, but the disagreements between + the various students of the subject need give us little concern. For our + present purpose it does not in the least matter whether the pyramids were + built three thousand or four thousand years before the beginning of our + era. It suffices that they date back to a period long antecedent to the + beginnings of civilization in Western Europe. They prove that the Egyptian + of that early day had attained a knowledge of practical mechanics which, + even from the twentieth-century point of view, is not to be spoken of + lightly. It has sometimes been suggested that these mighty pyramids, built + as they are of great blocks of stone, speak for an almost miraculous + knowledge on the part of their builders; but a saner view of the + conditions gives no warrant for this thought. Diodoras, the Sicilian, in + his famous World's History, written about the beginning of our era, + explains the building of the pyramids by suggesting that great quantities + of earth were piled against the side of the rising structure to form an + inclined plane up which the blocks of stone were dragged. He gives us + certain figures, based, doubtless, on reports made to him by Egyptian + priests, who in turn drew upon the traditions of their country, perhaps + even upon written records no longer preserved. He says that one hundred + and twenty thousand men were employed in the construction of the largest + pyramid, and that, notwithstanding the size of this host of workers, the + task occupied twenty years. We must not place too much dependence upon + such figures as these, for the ancient historians are notoriously given to + exaggeration in recording numbers; yet we need not doubt that the report + given by Diodorus is substantially accurate in its main outlines as to the + method through which the pyramids were constructed. A host of men putting + their added weight and strength to the task, with the aid of ropes, + pulleys, rollers, and levers, and utilizing the principle of the inclined + plane, could undoubtedly move and elevate and place in position the + largest blocks that enter into the pyramids or—what seems even more + wonderful—the most gigantic obelisks, without the aid of any other + kind of mechanism or of any more occult power. The same hands could, as + Diodorus suggests, remove all trace of the debris of construction and + leave the pyramids and obelisks standing in weird isolation, as if sprung + into being through a miracle. + </p> + <p> + ASTRONOMICAL SCIENCE + </p> + <p> + It has been necessary to bear in mind these phases of practical + civilization because much that we know of the purely scientific + attainments of the Egyptians is based upon modern observation of their + pyramids and temples. It was early observed, for example, that the + pyramids are obviously oriented as regards the direction in which they + face, in strict accordance with some astronomical principle. Early in the + nineteenth century the Frenchman Biot made interesting studies in regard + to this subject, and a hundred years later, in our own time, Sir Joseph + Norman Lockyer, following up the work of various intermediary observers, + has given the subject much attention, making it the central theme of his + work on The Dawn of Astronomy.(1) Lockyer's researches make it clear that + in the main the temples of Egypt were oriented with reference to the point + at which the sun rises on the day of the summer solstice. The time of the + solstice had peculiar interest for the Egyptians, because it corresponded + rather closely with the time of the rising of the Nile. The floods of that + river appear with very great regularity; the on-rushing tide reaches the + region of Heliopolis and Memphis almost precisely on the day of the summer + solstice. The time varies at different stages of the river's course, but + as the civilization of the early dynasties centred at Memphis, + observations made at this place had widest vogue. + </p> + <p> + Considering the all-essential character of the Nile floods-without which + civilization would be impossible in Egypt—it is not strange that the + time of their appearance should be taken as marking the beginning of a new + year. The fact that their coming coincides with the solstice makes such a + division of the calendar perfectly natural. In point of fact, from the + earliest periods of which records have come down to us, the new year of + the Egyptians dates from the summer solstice. It is certain that from the + earliest historical periods the Egyptians were aware of the approximate + length of the year. It would be strange were it otherwise, considering the + ease with which a record of days could be kept from Nile flood to Nile + flood, or from solstice to solstice. But this, of course, applies only to + an approximate count. There is some reason to believe that in the earliest + period the Egyptians made this count only 360 days. The fact that their + year was divided into twelve months of thirty days each lends color to + this belief; but, in any event, the mistake was discovered in due time and + a partial remedy was applied through the interpolation of a "little month" + of five days between the end of the twelfth month and the new year. This + nearly but not quite remedied the matter. What it obviously failed to do + was to take account of that additional quarter of a day which really + rounds out the actual year. + </p> + <p> + It would have been a vastly convenient thing for humanity had it chanced + that the earth had so accommodated its rotary motion with its speed of + transit about the sun as to make its annual flight in precisely 360 days. + Twelve lunar months of thirty days each would then have coincided exactly + with the solar year, and most of the complexities of the calendar, which + have so puzzled historical students, would have been avoided; but, on the + other hand, perhaps this very simplicity would have proved detrimental to + astronomical science by preventing men from searching the heavens as + carefully as they have done. Be that as it may, the complexity exists. The + actual year of three hundred and sixty-five and (about) one-quarter days + cannot be divided evenly into months, and some such expedient as the + intercalation of days here and there is essential, else the calendar will + become absolutely out of harmony with the seasons. + </p> + <p> + In the case of the Egyptians, the attempt at adjustment was made, as just + noted, by the introduction of the five days, constituting what the + Egyptians themselves termed "the five days over and above the year." These + so-called epagomenal days were undoubtedly introduced at a very early + period. Maspero holds that they were in use before the first Thinite + dynasty, citing in evidence the fact that the legend of Osiris explains + these days as having been created by the god Thot in order to permit Nuit + to give birth to all her children; this expedient being necessary to + overcome a ban which had been pronounced against Nuit, according to which + she could not give birth to children on any day of the year. But, of + course, the five additional days do not suffice fully to rectify the + calendar. There remains the additional quarter of a day to be accounted + for. This, of course, amounts to a full day every fourth year. We shall + see that later Alexandrian science hit upon the expedient of adding a day + to every fourth year; an expedient which the Julian calendar adopted and + which still gives us our familiar leap-year. But, unfortunately, the + ancient Egyptian failed to recognize the need of this additional day, or + if he did recognize it he failed to act on his knowledge, and so it + happened that, starting somewhere back in the remote past with a new + year's day that coincided with the inundation of the Nile, there was a + constantly shifting maladjustment of calendar and seasons as time went on. + </p> + <p> + The Egyptian seasons, it should be explained, were three in number: the + season of the inundation, the season of the seed-time, and the season of + the harvest; each season being, of course, four months in extent. + Originally, as just mentioned, the season of the inundations began and + coincided with the actual time of inundation. The more precise fixing of + new year's day was accomplished through observation of the time of the + so-called heliacal rising of the dog-star, Sirius, which bore the Egyptian + name Sothis. It chances that, as viewed from about the region of + Heliopolis, the sun at the time of the summer solstice occupies an + apparent position in the heavens close to the dog-star. Now, as is well + known, the Egyptians, seeing divinity back of almost every phenomenon of + nature, very naturally paid particular reverence to so obviously + influential a personage as the sun-god. In particular they thought it + fitting to do homage to him just as he was starting out on his tour of + Egypt in the morning; and that they might know the precise moment of his + coming, the Egyptian astronomer priests, perched on the hill-tops near + their temples, were wont to scan the eastern horizon with reference to + some star which had been observed to precede the solar luminary. Of course + the precession of the equinoxes, due to that axial wobble in which our + clumsy earth indulges, would change the apparent position of the fixed + stars in reference to the sun, so that the same star could not do service + as heliacal messenger indefinitely; but, on the other hand, these changes + are so slow that observations by many generations of astronomers would be + required to detect the shifting. It is believed by Lockyer, though the + evidence is not quite demonstrative, that the astronomical observations of + the Egyptians date back to a period when Sothis, the dog-star, was not in + close association with the sun on the morning of the summer solstice. Yet, + according to the calculations of Biot, the heliacal rising of Sothis at + the solstice was noted as early as the year 3285 B.C., and it is certain + that this star continued throughout subsequent centuries to keep this + position of peculiar prestige. Hence it was that Sothis came to be + associated with Isis, one of the most important divinities of Egypt, and + that the day in which Sothis was first visible in the morning sky marked + the beginning of the new year; that day coinciding, as already noted, with + the summer solstice and with the beginning of the Nile flow. + </p> + <p> + But now for the difficulties introduced by that unreckoned quarter of a + day. Obviously with a calendar of 365 days only, at the end of four years, + the calendar year, or vague year, as the Egyptians came to call it, had + gained by one full day upon the actual solar year—that is to say, + the heliacal rising of Sothis, the dog-star, would not occur on new year's + day of the faulty calendar, but a day later. And with each succeeding + period of four years the day of heliacal rising, which marked the true + beginning of the year—and which still, of course, coincided with the + inundation—would have fallen another day behind the calendar. In the + course of 120 years an entire month would be lost; and in 480 years so + great would become the shifting that the seasons would be altogether + misplaced; the actual time of inundations corresponding with what the + calendar registered as the seed-time, and the actual seed-time in turn + corresponding with the harvest-time of the calendar. + </p> + <p> + At first thought this seems very awkward and confusing, but in all + probability the effects were by no means so much so in actual practice. We + need go no farther than to our own experience to know that the names of + seasons, as of months and days, come to have in the minds of most of us a + purely conventional significance. Few of us stop to give a thought to the + meaning of the words January, February, etc., except as they connote + certain climatic conditions. If, then, our own calendar were so defective + that in the course of 120 years the month of February had shifted back to + occupy the position of the original January, the change would have been so + gradual, covering the period of two life-times or of four or five average + generations, that it might well escape general observation. + </p> + <p> + Each succeeding generation of Egyptians, then, may not improbably have + associated the names of the seasons with the contemporary climatic + conditions, troubling themselves little with the thought that in an + earlier age the climatic conditions for each period of the calendar were + quite different. We cannot well suppose, however, that the astronomer + priests were oblivious to the true state of things. Upon them devolved the + duty of predicting the time of the Nile flood; a duty they were enabled to + perform without difficulty through observation of the rising of the + solstitial sun and its Sothic messenger. To these observers it must + finally have been apparent that the shifting of the seasons was at the + rate of one day in four years; this known, it required no great + mathematical skill to compute that this shifting would finally effect a + complete circuit of the calendar, so that after (4 X 365 =) 1460 years the + first day of the calendar year would again coincide with the heliacal + rising of Sothis and with the coming of the Nile flood. In other words, + 1461 vague years or Egyptian calendar years Of 365 days each correspond to + 1460 actual solar years of 365 1/4 days each. This period, measured thus + by the heliacal rising of Sothis, is spoken of as the Sothic cycle. + </p> + <p> + To us who are trained from childhood to understand that the year consists + of (approximately) 365 1/4 days, and to know that the calendar may be + regulated approximately by the introduction of an extra day every fourth + year, this recognition of the Sothic cycle seems simple enough. Yet if the + average man of us will reflect how little he knows, of his own knowledge, + of the exact length of the year, it will soon become evident that the + appreciation of the faults of the calendar and the knowledge of its + periodical adjustment constituted a relatively high development of + scientific knowledge on the part of the Egyptian astronomer. It may be + added that various efforts to reform the calendar were made by the ancient + Egyptians, but that they cannot be credited with a satisfactory solution + of the problem; for, of course, the Alexandrian scientists of the + Ptolemaic period (whose work we shall have occasion to review presently) + were not Egyptians in any proper sense of the word, but Greeks. + </p> + <p> + Since so much of the time of the astronomer priests was devoted to + observation of the heavenly bodies, it is not surprising that they should + have mapped out the apparent course of the moon and the visible planets in + their nightly tour of the heavens, and that they should have divided the + stars of the firmament into more or less arbitrary groups or + constellations. That they did so is evidenced by various sculptured + representations of constellations corresponding to signs of the zodiac + which still ornament the ceilings of various ancient temples. + Unfortunately the decorative sense, which was always predominant with the + Egyptian sculptor, led him to take various liberties with the distribution + of figures in these representations of the constellations, so that the + inferences drawn from them as to the exact map of the heavens as the + Egyptians conceived it cannot be fully relied upon. It appears, however, + that the Egyptian astronomer divided the zodiac into twenty-four decani, + or constellations. The arbitrary groupings of figures, with the aid of + which these are delineated, bear a close resemblance to the equally + arbitrary outlines which we are still accustomed to use for the same + purpose. + </p> + <p> + IDEAS OF COSMOLOGY + </p> + <p> + In viewing this astronomical system of the Egyptians one cannot avoid the + question as to just what interpretation was placed upon it as regards the + actual mechanical structure of the universe. A proximal answer to the + question is supplied us with a good deal of clearness. It appears that the + Egyptian conceived the sky as a sort of tangible or material roof placed + above the world, and supported at each of its four corners by a column or + pillar, which was later on conceived as a great mountain. The earth itself + was conceived to be a rectangular box, longer from north to south than + from east to west; the upper surface of this box, upon which man lived, + being slightly concave and having, of course, the valley of the Nile as + its centre. The pillars of support were situated at the points of the + compass; the northern one being located beyond the Mediterranean Sea; the + southern one away beyond the habitable regions towards the source of the + Nile, and the eastern and western ones in equally inaccessible regions. + Circling about the southern side of the world was a great river suspended + in mid-air on something comparable to mountain cliffs; on which river the + sun-god made his daily course in a boat, fighting day by day his + ever-recurring battle against Set, the demon of darkness. The wide channel + of this river enabled the sun-god to alter his course from time to time, + as he is observed to do; in winter directing his bark towards the farther + bank of the channel; in summer gliding close to the nearer bank. As to the + stars, they were similar lights, suspended from the vault of the heaven; + but just how their observed motion of translation across the heavens was + explained is not apparent. It is more than probable that no one + explanation was, universally accepted. + </p> + <p> + In explaining the origin of this mechanism of the heavens, the Egyptian + imagination ran riot. Each separate part of Egypt had its own hierarchy of + gods, and more or less its own explanations of cosmogony. There does not + appear to have been any one central story of creation that found universal + acceptance, any more than there was one specific deity everywhere + recognized as supreme among the gods. Perhaps the most interesting of the + cosmogonic myths was that which conceived that Nuit, the goddess of night, + had been torn from the arms of her husband, Sibu the earth-god, and + elevated to the sky despite her protests and her husband's struggles, + there to remain supported by her four limbs, which became metamorphosed + into the pillars, or mountains, already mentioned. The forcible elevation + of Nuit had been effected on the day of creation by a new god, Shu, who + came forth from the primeval waters. A painting on the mummy case of one + Betuhamon, now in the Turin Museum, illustrates, in the graphic manner so + characteristic of the Egyptians, this act of creation. As Maspero(2) + points out, the struggle of Sibu resulted in contorted attitudes to which + the irregularities of the earth's surface are to be ascribed. + </p> + <p> + In contemplating such a scheme of celestial mechanics as that just + outlined, one cannot avoid raising the question as to just the degree of + literalness which the Egyptians themselves put upon it. We know how + essentially eye-minded the Egyptian was, to use a modern psychological + phrase—that is to say, how essential to him it seemed that all his + conceptions should be visualized. The evidences of this are everywhere: + all his gods were made tangible; he believed in the immortality of the + soul, yet he could not conceive of such immortality except in association + with an immortal body; he must mummify the body of the dead, else, as he + firmly believed, the dissolution of the spirit would take place along with + the dissolution of the body itself. His world was peopled everywhere with + spirits, but they were spirits associated always with corporeal bodies; + his gods found lodgment in sun and moon and stars; in earth and water; in + the bodies of reptiles and birds and mammals. He worshipped all of these + things: the sun, the moon, water, earth, the spirit of the Nile, the ibis, + the cat, the ram, and apis the bull; but, so far as we can judge, his + imagination did not reach to the idea of an absolutely incorporeal deity. + Similarly his conception of the mechanism of the heavens must be a + tangibly mechanical one. He must think of the starry firmament as a + substantial entity which could not defy the law of gravitation, and which, + therefore, must have the same manner of support as is required by the roof + of a house or temple. We know that this idea of the materiality of the + firmament found elaborate expression in those later cosmological guesses + which were to dominate the thought of Europe until the time of Newton. We + need not doubt, therefore, that for the Egyptian this solid vault of the + heavens had a very real existence. If now and then some dreamer conceived + the great bodies of the firmament as floating in a less material plenum—and + such iconoclastic dreamers there are in all ages—no record of his + musings has come down to us, and we must freely admit that if such + thoughts existed they were alien to the character of the Egyptian mind as + a whole. + </p> + <p> + While the Egyptians conceived the heavenly bodies as the abiding-place of + various of their deities, it does not appear that they practised astrology + in the later acceptance of that word. This is the more remarkable since + the conception of lucky and unlucky days was carried by the Egyptians to + the extremes of absurdity. "One day was lucky or unlucky," says Erman,(3) + "according as a good or bad mythological incident took place on that day. + For instance, the 1st of Mechir, on which day the sky was raised, and the + 27th of Athyr, when Horus and, Set concluded peace together and divided + the world between them, were lucky days; on the other hand, the 14th of + Tybi, on which Isis and Nephthys mourned for Osiris, was an unlucky day. + With the unlucky days, which, fortunately, were less in number than the + lucky days, they distinguished different degrees of ill-luck. Some were + very unlucky, others only threatened ill-luck, and many, like the 17th and + the 27th Choiakh, were partly good and partly bad according to the time of + day. Lucky days might, as a rule, be disregarded. At most it might be as + well to visit some specially renowned temple, or to 'celebrate a joyful + day at home,' but no particular precautions were really necessary; and, + above all, it was said, 'what thou also seest on the day is lucky.' It was + quite otherwise with the unlucky and dangerous days, which imposed so many + and such great limitations on people that those who wished to be prudent + were always obliged to bear them in mind when determining on any course of + action. Certain conditions were easy to carry out. Music and singing were + to be avoided on the 14th Tybi, the day of the mourning of Osiris, and no + one was allowed to wash on the 16th Tybi; whilst the name of Set might not + be pronounced on the 24th of Pharmuthi. Fish was forbidden on certain + days; and what was still more difficult in a country so rich in mice, on + the 12th of Tybi no mouse might be seen. The most tiresome prohibitions, + however, were those which occurred not infrequently, namely, those + concerning work and going out: for instance, four times in Paophi the + people had to 'do nothing at all,' and five times to sit the whole day or + half the day in the house; and the same rule had to be observed each + month. It was impossible to rejoice if a child was born on the 23d of + Thoth; the parents knew it could not live. Those born on the 20th of + Choiakh would become blind, and those born on the 3d of Choiakh, deaf." + </p> + <p> + CHARMS AND INCANTATIONS + </p> + <p> + Where such conceptions as these pertained, it goes without saying that + charms and incantations intended to break the spell of the unlucky omens + were equally prevalent. Such incantations consisted usually of the + recitation of certain phrases based originally, it would appear, upon + incidents in the history of the gods. The words which the god had spoken + in connection with some lucky incident would, it was thought, prove + effective now in bringing good luck to the human supplicant—that is + to say, the magician hoped through repeating the words of the god to + exercise the magic power of the god. It was even possible, with the aid of + the magical observances, partly to balk fate itself. Thus the person + predestined through birth on an unlucky day to die of a serpent bite might + postpone the time of this fateful visitation to extreme old age. The like + uncertainty attached to those spells which one person was supposed to be + able to exercise over another. It was held, for example, that if something + belonging to an individual, such as a lock of hair or a paring of the + nails, could be secured and incorporated in a waxen figure, this figure + would be intimately associated with the personality of that individual. An + enemy might thus secure occult power over one; any indignity practised + upon the waxen figure would result in like injury to its human prototype. + If the figure were bruised or beaten, some accident would overtake its + double; if the image were placed over a fire, the human being would fall + into a fever, and so on. But, of course, such mysterious evils as these + would be met and combated by equally mysterious processes; and so it was + that the entire art of medicine was closely linked with magical practices. + It was not, indeed, held, according to Maspero, that the magical spells of + enemies were the sole sources of human ailments, but one could never be + sure to what extent such spells entered into the affliction; and so + closely were the human activities associated in the mind of the Egyptian + with one form or another of occult influences that purely physical + conditions were at a discount. In the later times, at any rate, the + physician was usually a priest, and there was a close association between + the material and spiritual phases of therapeutics. Erman(4) tells us that + the following formula had to be recited at the preparation of all + medicaments: "That Isis might make free, make free. That Isis might make + Horus free from all evil that his brother Set had done to him when he slew + his father, Osiris. O Isis, great enchantress, free me, release me from + all evil red things, from the fever of the god, and the fever of the + goddess, from death and death from pain, and the pain which comes over me; + as thou hast freed, as thou hast released thy son Horus, whilst I enter + into the fire and come forth from the water," etc. Again, when the invalid + took the medicine, an incantation had to be said which began thus: "Come + remedy, come drive it out of my heart, out of these limbs strong in magic + power with the remedy." He adds: "There may have been a few rationalists + amongst the Egyptian doctors, for the number of magic formulae varies much + in the different books. The book that we have specially taken for a + foundation for this account of Egyptian medicine—the great papyrus + of the eighteenth dynasty edited by Ebers(5)—contains, for instance, + far fewer exorcisms than some later writings with similar contents, + probably because the doctor who compiled this book of recipes from older + sources had very little liking for magic." + </p> + <p> + It must be understood, however—indeed, what has just been said + implies as much—that the physician by no means relied upon + incantations alone; on the contrary, he equipped himself with an + astonishing variety of medicaments. He had a particular fondness for what + the modern physician speaks of as a "shot-gun" prescription—one + containing a great variety of ingredients. Not only did herbs of many + kinds enter into this, but such substances as lizard's blood, the teeth of + swine, putrid meat, the moisture from pigs' ears, boiled horn, and + numerous other even more repellent ingredients. Whoever is familiar with + the formulae employed by European physicians even so recently as the + eighteenth century will note a striking similarity here. Erman points out + that the modern Egyptian even of this day holds closely to many of the + practices of his remote ancestor. In particular, the efficacy of the + beetle as a medicinal agent has stood the test of ages of practice. + "Against all kinds of witchcraft," says an ancient formula, "a great + scarabaeus beetle; cut off his head and wings, boil him; put him in oil + and lay him out; then cook his head and wings, put them in snake fat, + boil, and let the patient drink the mixture." The modern Egyptian, says + Erman, uses almost precisely the same recipe, except that the snake fat is + replaced by modern oil. + </p> + <p> + In evidence of the importance which was attached to practical medicine in + the Egypt of an early day, the names of several physicians have come down + to us from an age which has preserved very few names indeed, save those of + kings. In reference to this Erman says(6): "We still know the names of + some of the early body physicians of this time; Sechmetna'eonch, 'chief + physician of the Pharaoh,' and Nesmenan his chief, the 'superintendent of + the physicians of the Pharaoh.' The priests also of the lioness-headed + goddess Sechmet seem to have been famed for their medical wisdom, whilst + the son of this goddess, the demi-god Imhotep, was in later times + considered to be the creator of medical knowledge. These ancient doctors + of the New Empire do not seem to have improved upon the older conceptions + about the construction of the human body." + </p> + <p> + As to the actual scientific attainments of the Egyptian physician, it is + difficult to speak with precision. Despite the cumbersome formulae and the + grotesque incantations, we need not doubt that a certain practical value + attended his therapeutics. He practised almost pure empiricism, however, + and certainly it must have been almost impossible to determine which ones, + if any, of the numerous ingredients of the prescription had real efficacy. + </p> + <p> + The practical anatomical knowledge of the physician, there is every reason + to believe, was extremely limited. At first thought it might seem that the + practice of embalming would have led to the custom of dissecting human + bodies, and that the Egyptians, as a result of this, would have excelled + in the knowledge of anatomy. But the actual results were rather the + reverse of this. Embalming the dead, it must be recalled, was a purely + religious observance. It took place under the superintendence of the + priests, but so great was the reverence for the human body that the + priests themselves were not permitted to make the abdominal incision which + was a necessary preliminary of the process. This incision, as we are + informed by both Herodotus(7) and Diodorus(8), was made by a special + officer, whose status, if we may believe the explicit statement of + Diodorus, was quite comparable to that of the modern hangman. The + paraschistas, as he was called, having performed his necessary but + obnoxious function, with the aid of a sharp Ethiopian stone, retired + hastily, leaving the remaining processes to the priests. These, however, + confined their observations to the abdominal viscera; under no + consideration did they make other incisions in the body. It follows, + therefore, that their opportunity for anatomical observations was most + limited. + </p> + <p> + Since even the necessary mutilation inflicted on the corpse was regarded + with such horror, it follows that anything in the way of dissection for a + less sacred purpose was absolutely prohibited. Probably the same + prohibition extended to a large number of animals, since most of these + were held sacred in one part of Egypt or another. Moreover, there is + nothing in what we know of the Egyptian mind to suggest the probability + that any Egyptian physician would make extensive anatomical observations + for the love of pure knowledge. All Egyptian science is eminently + practical. If we think of the Egyptian as mysterious, it is because of the + superstitious observances that we everywhere associate with his daily + acts; but these, as we have already tried to make clear, were really based + on scientific observations of a kind, and the attempt at true inferences + from these observations. But whether or not the Egyptian physician desired + anatomical knowledge, the results of his inquiries were certainly most + meagre. The essentials of his system had to do with a series of vessels, + alleged to be twenty-two or twenty-four in number, which penetrated the + head and were distributed in pairs to the various members of the body, and + which were vaguely thought of as carriers of water, air, excretory fluids, + etc. Yet back of this vagueness, as must not be overlooked, there was an + all-essential recognition of the heart as the central vascular organ. The + heart is called the beginning of all the members. Its vessels, we are + told, "lead to all the members; whether the doctor lays his finger on the + forehead, on the back of the head, on the hands, on the place of the + stomach (?), on the arms, or on the feet, everywhere he meets with the + heart, because its vessels lead to all the members."(9) This recognition + of the pulse must be credited to the Egyptian physician as a piece of + practical knowledge, in some measure off-setting the vagueness of his + anatomical theories. + </p> + <p> + ABSTRACT SCIENCE + </p> + <p> + But, indeed, practical knowledge was, as has been said over and over, the + essential characteristic of Egyptian science. Yet another illustration of + this is furnished us if we turn to the more abstract departments of + thought and inquire what were the Egyptian attempts in such a field as + mathematics. The answer does not tend greatly to increase our admiration + for the Egyptian mind. We are led to see, indeed, that the Egyptian + merchant was able to perform all the computations necessary to his craft, + but we are forced to conclude that the knowledge of numbers scarcely + extended beyond this, and that even here the methods of reckoning were + tedious and cumbersome. Our knowledge of the subject rests largely upon + the so-called papyrus Rhind,(10) which is a sort of mythological hand-book + of the ancient Egyptians. Analyzing this document, Professor Erman + concludes that the knowledge of the Egyptians was adequate to all + practical requirements. Their mathematics taught them "how in the exchange + of bread for beer the respective value was to be determined when converted + into a quantity of corn; how to reckon the size of a field; how to + determine how a given quantity of corn would go into a granary of a + certain size," and like every-day problems. Yet they were obliged to make + some of their simple computations in a very roundabout way. It would + appear, for example, that their mental arithmetic did not enable them to + multiply by a number larger than two, and that they did not reach a clear + conception of complex fractional numbers. They did, indeed, recognize that + each part of an object divided into 10 pieces became 1/10 of that object; + they even grasped the idea of 2/3 this being a conception easily + visualized; but they apparently did not visualize such a conception as + 3/10 except in the crude form of 1/10 plus 1/10 plus 1/10. Their entire + idea of division seems defective. They viewed the subject from the more + elementary stand-point of multiplication. Thus, in order to find out how + many times 7 is contained in 77, an existing example shows that the + numbers representing 1 times 7, 2 times 7, 4 times 7, 8 times 7 were set + down successively and various experimental additions made to find out + which sets of these numbers aggregated 77. + </p> +<pre xml:space="preserve"> + —1 7 + —2 14 + —4 28 + —8 56 +</pre> + <p> + A line before the first, second, and fourth of these numbers indicated + that it is necessary to multiply 7 by 1 plus 2 plus 8—that is, by + 11, in order to obtain 77; that is to say, 7 goes 11 times in 77. All this + seems very cumbersome indeed, yet we must not overlook the fact that the + process which goes on in our own minds in performing such a problem as + this is precisely similar, except that we have learned to slur over + certain of the intermediate steps with the aid of a memorized + multiplication table. In the last analysis, division is only the obverse + side of multiplication, and any one who has not learned his multiplication + table is reduced to some such expedient as that of the Egyptian. Indeed, + whenever we pass beyond the range of our memorized multiplication + table-which for most of us ends with the twelves—the experimental + character of the trial multiplication through which division is finally + effected does not so greatly differ from the experimental efforts which + the Egyptian was obliged to apply to smaller numbers. + </p> + <p> + Despite his defective comprehension of fractions, the Egyptian was able to + work out problems of relative complexity; for example, he could determine + the answer of such a problem as this: a number together with its fifth + part makes 21; what is the number? The process by which the Egyptian + solved this problem seems very cumbersome to any one for whom a + rudimentary knowledge of algebra makes it simple, yet the method which we + employ differs only in that we are enabled, thanks to our hypothetical x, + to make a short cut, and the essential fact must not be overlooked that + the Egyptian reached a correct solution of the problem. With all due + desire to give credit, however, the fact remains that the Egyptian was but + a crude mathematician. Here, as elsewhere, it is impossible to admire him + for any high development of theoretical science. First, last, and all the + time, he was practical, and there is nothing to show that the thought of + science for its own sake, for the mere love of knowing, ever entered his + head. + </p> + <p> + In general, then, we must admit that the Egyptian had not progressed far + in the hard way of abstract thinking. He worshipped everything about him + because he feared the result of failing to do so. He embalmed the dead + lest the spirit of the neglected one might come to torment him. Eye-minded + as he was, he came to have an artistic sense, to love decorative effects. + But he let these always take precedence over his sense of truth; as, for + example, when he modified his lists of kings at Abydos to fit the space + which the architect had left to be filled; he had no historical sense to + show to him that truth should take precedence over mere decoration. And + everywhere he lived in the same happy-go-lucky way. He loved personal + ease, the pleasures of the table, the luxuries of life, games, + recreations, festivals. He took no heed for the morrow, except as the + morrow might minister to his personal needs. Essentially a sensual being, + he scarcely conceived the meaning of the intellectual life in the modern + sense of the term. He had perforce learned some things about astronomy, + because these were necessary to his worship of the gods; about practical + medicine, because this ministered to his material needs; about practical + arithmetic, because this aided him in every-day affairs. The bare + rudiments of an historical science may be said to be crudely outlined in + his defective lists of kings. But beyond this he did not go. Science as + science, and for its own sake, was unknown to him. He had gods for all + material functions, and festivals in honor of every god; but there was no + goddess of mere wisdom in his pantheon. The conception of Minerva was + reserved for the creative genius of another people. + </p> + <p> + <a name="link2H_4_0005" id="link2H_4_0005"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + III. SCIENCE OF BABYLONIA AND ASSYRIA + </h2> + <p> + Throughout classical antiquity Egyptian science was famous. We know that + Plato spent some years in Egypt in the hope of penetrating the alleged + mysteries of its fabled learning; and the story of the Egyptian priest who + patronizingly assured Solon that the Greeks were but babes was quoted + everywhere without disapproval. Even so late as the time of Augustus, we + find Diodorus, the Sicilian, looking back with veneration upon the + Oriental learning, to which Pliny also refers with unbounded respect. From + what we have seen of Egyptian science, all this furnishes us with a + somewhat striking commentary upon the attainments of the Greeks and Romans + themselves. To refer at length to this would be to anticipate our purpose; + what now concerns us is to recall that all along there was another nation, + or group of nations, that disputed the palm for scientific attainments. + This group of nations found a home in the valley of the Tigris and + Euphrates. Their land was named Mesopotamia by the Greeks, because a large + part of it lay between the two rivers just mentioned. The peoples + themselves are familiar to every one as the Babylonians and the Assyrians. + These peoples were of Semitic stock—allied, therefore, to the + ancient Hebrews and Phoenicians and of the same racial stem with the + Arameans and Arabs. + </p> + <p> + The great capital of the Babylonians during the later period of their + history was the famed city of Babylon itself; the most famous capital of + the Assyrians was Nineveh, that city to which, as every Bible-student will + recall, the prophet Jonah was journeying when he had a much-exploited + experience, the record of which forms no part of scientific annals. It was + the kings of Assyria, issuing from their palaces in Nineveh, who dominated + the civilization of Western Asia during the heyday of Hebrew history, and + whose deeds are so frequently mentioned in the Hebrew chronicles. Later + on, in the year 606 B.C., Nineveh was overthrown by the Medes(1) and + Babylonians. The famous city was completely destroyed, never to be + rebuilt. Babylon, however, though conquered subsequently by Cyrus and held + in subjection by Darius,(2) the Persian kings, continued to hold sway as a + great world-capital for some centuries. The last great historical event + that occurred within its walls was the death of Alexander the Great, which + took place there in the year 322 B.C. + </p> + <p> + In the time of Herodotus the fame of Babylon was at its height, and the + father of history has left us a most entertaining account of what he saw + when he visited the wonderful capital. Unfortunately, Herodotus was not a + scholar in the proper acceptance of the term. He probably had no inkling + of the Babylonian language, so the voluminous records of its literature + were entirely shut off from his observation. He therefore enlightens us + but little regarding the science of the Babylonians, though his + observations on their practical civilization give us incidental references + of no small importance. Somewhat more detailed references to the + scientific attainments of the Babylonians are found in the fragments that + have come down to us of the writings of the great Babylonian historian, + Berosus,(3) who was born in Babylon about 330 B.C., and who was, + therefore, a contemporary of Alexander the Great. But the writings of + Berosus also, or at least such parts of them as have come down to us, + leave very much to be desired in point of explicitness. They give some + glimpses of Babylonian history, and they detail at some length the strange + mythical tales of creation that entered into the Babylonian conception of + cosmogony—details which find their counterpart in the allied + recitals of the Hebrews. But taken all in all, the glimpses of the actual + state of Chaldean(4) learning, as it was commonly called, amounted to + scarcely more than vague wonder-tales. No one really knew just what + interpretation to put upon these tales until the explorers of the + nineteenth century had excavated the ruins of the Babylonian and Assyrian + cities, bringing to light the relics of their wonderful civilization. But + these relics fortunately included vast numbers of written documents, + inscribed on tablets, prisms, and cylinders of terra-cotta. When + nineteenth-century scholarship had penetrated the mysteries of the strange + script, and ferreted out the secrets of an unknown tongue, the world at + last was in possession of authentic records by which the traditions + regarding the Babylonians and Assyrians could be tested. Thanks to these + materials, a new science commonly spoken of as Assyriology came into + being, and a most important chapter of human history was brought to light. + It became apparent that the Greek ideas concerning Mesopotamia, though + vague in the extreme, were founded on fact. No one any longer questions + that the Mesopotamian civilization was fully on a par with that of Egypt; + indeed, it is rather held that superiority lay with the Asiatics. + Certainly, in point of purely scientific attainments, the Babylonians + passed somewhat beyond their Egyptian competitors. All the evidence seems + to suggest also that the Babylonian civilization was even more ancient + than that of Egypt. The precise dates are here in dispute; nor for our + present purpose need they greatly concern us. But the Assyrio-Babylonian + records have much greater historical accuracy as regards matters of + chronology than have the Egyptian, and it is believed that our knowledge + of the early Babylonian history is carried back, with some certainty, to + King Sargon of Agade,(5) for whom the date 3800 B.C. is generally + accepted; while somewhat vaguer records give us glimpses of periods as + remote as the sixth, perhaps even the seventh or eighth millenniums before + our era. + </p> + <p> + At a very early period Babylon itself was not a capital and Nineveh had + not come into existence. The important cities, such as Nippur and + Shirpurla, were situated farther to the south. It is on the site of these + cities that the recent excavations have been made, such as those of the + University of Pennsylvania expeditions at Nippur,(6) which are giving us + glimpses into remoter recesses of the historical period. + </p> + <p> + Even if we disregard the more problematical early dates, we are still + concerned with the records of a civilization extending unbroken throughout + a period of about four thousand years; the actual period is in all + probability twice or thrice that. Naturally enough, the current of history + is not an unbroken stream throughout this long epoch. It appears that at + least two utterly different ethnic elements are involved. A preponderance + of evidence seems to show that the earliest civilized inhabitants of + Mesopotamia were not Semitic, but an alien race, which is now commonly + spoken of as Sumerian. This people, of whom we catch glimpses chiefly + through the records of its successors, appears to have been subjugated or + overthrown by Semitic invaders, who, coming perhaps from Arabia (their + origin is in dispute), took possession of the region of the Tigris and + Euphrates, learned from the Sumerians many of the useful arts, and, partly + perhaps because of their mixed lineage, were enabled to develop the most + wonderful civilization of antiquity. Could we analyze the details of this + civilization from its earliest to its latest period we should of course + find the same changes which always attend racial progress and decay. We + should then be able, no doubt, to speak of certain golden epochs and their + periods of decline. To a certain meagre extent we are able to do this now. + We know, for example, that King Khammurabi, who lived about 2200 B.C., was + a great law-giver, the ancient prototype of Justinian; and the epochs of + such Assyrian kings as Sargon II., Asshurnazirpal, Sennacherib, and + Asshurbanapal stand out with much distinctness. Yet, as a whole, the + record does not enable us to trace with clearness the progress of + scientific thought. At best we can gain fewer glimpses in this direction + than in almost any other, for it is the record of war and conquest rather + than of the peaceful arts that commanded the attention of the ancient + scribe. So in dealing with the scientific achievements of these peoples, + we shall perforce consider their varied civilizations as a unity, and + attempt, as best we may, to summarize their achievements as a whole. For + the most part, we shall not attempt to discriminate as to what share in + the final product was due to Sumerian, what to Babylonian, and what to + Assyrian. We shall speak of Babylonian science as including all these + elements; and drawing our information chiefly from the relatively late + Assyrian and Babylonian sources, which, therefore, represent the + culminating achievements of all these ages of effort, we shall attempt to + discover what was the actual status of Mesopotamian science at its climax. + In so far as we succeed, we shall be able to judge what scientific + heritage Europe received from the Orient; for in the records of Babylonian + science we have to do with the Eastern mind at its best. Let us turn to + the specific inquiry as to the achievements of the Chaldean scientist + whose fame so dazzled the eyes of his contemporaries of the classic world. + </p> + <p> + BABYLONIAN ASTRONOMY + </p> + <p> + Our first concern naturally is astronomy, this being here, as in Egypt, + the first-born and the most important of the sciences. The fame of the + Chaldean astronomer was indeed what chiefly commanded the admiration of + the Greeks, and it was through the results of astronomical observations + that Babylonia transmitted her most important influences to the Western + world. "Our division of time is of Babylonian origin," says Hornmel;(7) + "to Babylonia we owe the week of seven days, with the names of the planets + for the days of the week, and the division into hours and months." Hence + the almost personal interest which we of to-day must needs feel in the + efforts of the Babylonian star-gazer. + </p> + <p> + It must not be supposed, however, that the Chaldean astronomer had made + any very extraordinary advances upon the knowledge of the Egyptian + "watchers of the night." After all, it required patient observation rather + than any peculiar genius in the observer to note in the course of time + such broad astronomical conditions as the regularity of the moon's phases, + and the relation of the lunar periods to the longer periodical + oscillations of the sun. Nor could the curious wanderings of the planets + escape the attention of even a moderately keen observer. The chief + distinction between the Chaldean and Egyptian astronomers appears to have + consisted in the relative importance they attached to various of the + phenomena which they both observed. The Egyptian, as we have seen, centred + his attention upon the sun. That luminary was the abode of one of his most + important gods. His worship was essentially solar. The Babylonian, on the + other hand, appears to have been peculiarly impressed with the importance + of the moon. He could not, of course, overlook the attention-compelling + fact of the solar year; but his unit of time was the lunar period of + thirty days, and his year consisted of twelve lunar periods, or 360 days. + He was perfectly aware, however, that this period did not coincide with + the actual year; but the relative unimportance which he ascribed to the + solar year is evidenced by the fact that he interpolated an added month to + adjust the calendar only once in six years. Indeed, it would appear that + the Babylonians and Assyrians did not adopt precisely the same method of + adjusting the calendar, since the Babylonians had two intercular months + called Elul and Adar, whereas the Assyrians had only a single such month, + called the second Adar.(8) (The Ve'Adar of the Hebrews.) This diversity + further emphasizes the fact that it was the lunar period which received + chief attention, the adjustment of this period with the solar seasons + being a necessary expedient of secondary importance. It is held that these + lunar periods have often been made to do service for years in the + Babylonian computations and in the allied computations of the early + Hebrews. The lives of the Hebrew patriarchs, for example, as recorded in + the Bible, are perhaps reckoned in lunar "years." Divided by twelve, the + "years" of Methuselah accord fairly with the usual experience of mankind. + </p> + <p> + Yet, on the other hand, the convenience of the solar year in computing + long periods of time was not unrecognized, since this period is utilized + in reckoning the reigns of the Assyrian kings. It may be added that the + reign of a king "was not reckoned from the day of his accession, but from + the Assyrian new year's day, either before or after the day of accession. + There does not appear to have been any fixed rule as to which new year's + day should be chosen; but from the number of known cases, it appears to + have been the general practice to count the reigning years from the new + year's day nearest the accession, and to call the period between the + accession day and the first new year's day 'the beginning of the reign,' + when the year from the new year's day was called the first year, and the + following ones were brought successively from it. Notwithstanding, in the + dates of several Assyrian and Babylonian sovereigns there are cases of the + year of accession being considered as the first year, thus giving two + reckonings for the reigns of various monarchs, among others, Shalmaneser, + Sennacherib, Nebuchadrezzar."(9) This uncertainty as to the years of + reckoning again emphasizes the fact that the solar year did not have for + the Assyrian chronology quite the same significance that it has for us. + </p> + <p> + The Assyrian month commenced on the evening when the new moon was first + observed, or, in case the moon was not visible, the new month started + thirty days after the last month. Since the actual lunar period is about + twenty-nine and one-half days, a practical adjustment was required between + the months themselves, and this was probably effected by counting + alternate months as Only 29 days in length. Mr. R. Campbell Thompson(10) + is led by his studies of the astrological tablets to emphasize this fact. + He believes that "the object of the astrological reports which related to + the appearance of the moon and sun was to help determine and foretell the + length of the lunar month." Mr. Thompson believes also that there is + evidence to show that the interculary month was added at a period less + than six years. In point of fact, it does not appear to be quite clearly + established as to precisely how the adjustment of days with the lunar + months, and lunar months with the solar year, was effected. It is clear, + however, according to Smith, "that the first 28 days of every month were + divided into four weeks of seven days each; the seventh, fourteenth, + twenty-first, twenty-eighth days respectively being Sabbaths, and that + there was a general prohibition of work on these days." Here, of course, + is the foundation of the Hebrew system of Sabbatical days which we have + inherited. The sacredness of the number seven itself—the belief in + which has not been quite shaken off even to this day—was deduced by + the Assyrian astronomer from his observation of the seven planetary bodies—namely, + Sin (the moon), Samas (the sun), Umunpawddu (Jupiter), Dilbat (Venus), + Kaimanu (Saturn), Gudud (Mercury), Mustabarru-mutanu (Mars).(11) Twelve + lunar periods, making up approximately the solar year, gave peculiar + importance to the number twelve also. Thus the zodiac was divided into + twelve signs which astronomers of all subsequent times have continued to + recognize; and the duodecimal system of counting took precedence with the + Babylonian mathematicians over the more primitive and, as it seems to us, + more satisfactory decimal system. + </p> + <p> + Another discrepancy between the Babylonian and Egyptian years appears in + the fact that the Babylonian new year dates from about the period of the + vernal equinox and not from the solstice. Lockyer associates this with the + fact that the periodical inundation of the Tigris and Euphrates occurs + about the equinoctial period, whereas, as we have seen, the Nile flood + comes at the time of the solstice. It is but natural that so important a + phenomenon as the Nile flood should make a strong impression upon the + minds of a people living in a valley. The fact that occasional excessive + inundations have led to most disastrous results is evidenced in the + incorporation of stories of the almost total destruction of mankind by + such floods among the myth tales of all peoples who reside in valley + countries. The flooding of the Tigris and Euphrates had not, it is true, + quite the same significance for the Mesopotamians that the Nile flood had + for the Egyptians. Nevertheless it was a most important phenomenon, and + may very readily be imagined to have been the most tangible index to the + seasons. But in recognizing the time of the inundations and the vernal + equinox, the Assyrians did not dethrone the moon from its accustomed + precedence, for the year was reckoned as commencing not precisely at the + vernal equinox, but at the new moon next before the equinox. + </p> + <p> + ASTROLOGY + </p> + <p> + Beyond marking the seasons, the chief interests that actuated the + Babylonian astronomer in his observations were astrological. After quoting + Diodorus to the effect that the Babylonian priests observed the position + of certain stars in order to cast horoscopes, Thompson tells us that from + a very early day the very name Chaldean became synonymous with magician. + He adds that "from Mesopotamia, by way of Greece and Rome, a certain + amount of Babylonian astrology made its way among the nations of the west, + and it is quite probable that many superstitions which we commonly record + as the peculiar product of western civilization took their origin from + those of the early dwellers on the alluvial lands of Mesopotamia. One + Assurbanipal, king of Assyria B.C. 668-626, added to the royal library at + Nineveh his contribution of tablets, which included many series of + documents which related exclusively to the astrology of the ancient + Babylonians, who in turn had borrowed it with modifications from the + Sumerian invaders of the country. Among these must be mentioned the series + which was commonly called 'the Day of Bel,' and which was decreed by the + learned to have been written in the time of the great Sargon I., king of + Agade, 3800 B.C. With such ancient works as these to guide them, the + profession of deducing omens from daily events reached such a pitch of + importance in the last Assyrian Empire that a system of making periodical + reports came into being. By these the king was informed of all the + occurrences in the heavens and on earth, and the results of astrological + studies in respect to after events. The heads of the astrological + profession were men of high rank and position, and their office was + hereditary. The variety of information contained in these reports is best + gathered from the fact that they were sent from cities as far removed from + each other as Assur in the north and Erech in the south, and it can only + be assumed that they were despatched by runners, or men mounted on swift + horses. As reports also came from Dilbat, Kutba, Nippur, and Bursippa, all + cities of ancient foundation, the king was probably well acquainted with + the general course of events in his empire."(12) + </p> + <p> + From certain passages in the astrological tablets, Thompson draws the + interesting conclusion that the Chaldean astronomers were acquainted with + some kind of a machine for reckoning time. He finds in one of the tablets + a phrase which he interprets to mean measure-governor, and he infers from + this the existence of a kind of a calculator. He calls attention also to + the fact that Sextus Empiricus(13) states that the clepsydra was known to + the Chaldeans, and that Herodotus asserts that the Greeks borrowed certain + measures of time from the Babylonians. He finds further corroboration in + the fact that the Babylonians had a time-measure by which they divided the + day and the night; a measure called kasbu, which contained two hours. In a + report relating to the day of the vernal equinox, it is stated that there + are six kasbu of the day and six kasbu of the night. + </p> + <p> + While the astrologers deduced their omens from all the celestial bodies + known to them, they chiefly gave attention to the moon, noting with great + care the shape of its horns, and deducing such a conclusion as that "if + the horns are pointed the king will overcome whatever he goreth," and that + "when the moon is low at its appearance, the submission (of the people) of + a far country will come."(14) The relations of the moon and sun were a + source of constant observation, it being noted whether the sun and moon + were seen together above the horizon; whether one set as the other rose, + and the like. And whatever the phenomena, there was always, of course, a + direct association between such phenomena and the well-being of human kind—in + particular the king, at whose instance, and doubtless at whose expense, + the observations were carried out. + </p> + <p> + From omens associated with the heavenly bodies it is but a step to omens + based upon other phenomena of nature, and we, shall see in a moment that + the Babylonian prophets made free use of their opportunities in this + direction also. But before we turn from the field of astronomy, it will be + well to inform ourselves as to what system the Chaldean astronomer had + invented in explanation of the mechanics of the universe. Our answer to + this inquiry is not quite as definite as could be desired, the vagueness + of the records, no doubt, coinciding with the like vagueness in the minds + of the Chaldeans themselves. So far as we can interpret the somewhat + mystical references that have come down to us, however, the Babylonian + cosmology would seem to have represented the earth as a circular plane + surrounded by a great circular river, beyond which rose an impregnable + barrier of mountains, and resting upon an infinite sea of waters. The + material vault of the heavens was supposed to find support upon the + outlying circle of mountains. But the precise mechanism through which the + observed revolution of the heavenly bodies was effected remains here, as + with the Egyptian cosmology, somewhat conjectural. The simple fact would + appear to be that, for the Chaldeans as for the Egyptians, despite their + most careful observations of the tangible phenomena of the heavens, no + really satisfactory mechanical conception of the cosmos was attainable. We + shall see in due course by what faltering steps the European imagination + advanced from the crude ideas of Egypt and Babylonia to the relatively + clear vision of Newton and Laplace. + </p> + <p> + CHALDEAN MAGIC + </p> + <p> + We turn now from the field of the astrologer to the closely allied + province of Chaldean magic—a province which includes the other; + which, indeed, is so all-encompassing as scarcely to leave any phase of + Babylonian thought outside its bounds. + </p> + <p> + The tablets having to do with omens, exorcisms, and the like magic + practices make up an astonishingly large proportion of the Babylonian + records. In viewing them it is hard to avoid the conclusion that the + superstitions which they evidenced absolutely dominated the life of the + Babylonians of every degree. Yet it must not be forgotten that the + greatest inconsistencies everywhere exist between the superstitious + beliefs of a people and the practical observances of that people. No other + problem is so difficult for the historian as that which confronts him when + he endeavors to penetrate the mysteries of an alien religion; and when, as + in the present case, the superstitions involved have been transmitted from + generation to generation, their exact practical phases as interpreted by + any particular generation must be somewhat problematical. The tablets upon + which our knowledge of these omens is based are many of them from the + libraries of the later kings of Nineveh; but the omens themselves are, in + such cases, inscribed in the original Accadian form in which they have + come down from remote ages, accompanied by an Assyrian translation. Thus + the superstitions involved had back of them hundreds of years, even + thousands of years, of precedent; and we need not doubt that the ideas + with which they are associated were interwoven with almost every thought + and deed of the life of the people. Professor Sayce assures us that the + Assyrians and Babylonians counted no fewer than three hundred spirits of + heaven, and six hundred spirits of earth. "Like the Jews of the Talmud," + he says, "they believed that the world was swarming with noxious spirits, + who produced the various diseases to which man is liable, and might be + swallowed with the food and drink which support life." Fox Talbot was + inclined to believe that exorcisms were the exclusive means used to drive + away the tormenting spirits. This seems unlikely, considering the uniform + association of drugs with the magical practices among their people. Yet + there is certainly a strange silence of the tablets in regard to medicine. + Talbot tells us that sometimes divine images were brought into the + sick-chamber, and written texts taken from holy books were placed on the + walls and bound around the sick man's members. If these failed, recourse + was had to the influence of the mamit, which the evil powers were unable + to resist. On a tablet, written in the Accadian language only, the + Assyrian version being taken, however, was found the following: + </p> +<pre xml:space="preserve"> + 1. Take a white cloth. In it place the mamit, + 2. in the sick man's right hand. + 3. Take a black cloth, + 4. wrap it around his left hand. + 5. Then all the evil spirits (a long list of them is given) + 6. and the sins which he has committed + 7. shall quit their hold of him + 8. and shall never return. +</pre> + <p> + The symbolism of the black cloth in the left hand seems evident. The dying + man repents of his former evil deeds, and he puts his trust in holiness, + symbolized by the white cloth in his right hand. Then follow some obscure + lines about the spirits: + </p> +<pre xml:space="preserve"> + 1. Their heads shall remove from his head. + 2. Their heads shall let go his hands. + 3. Their feet shall depart from his feet. +</pre> + <p> + Which perhaps may be explained thus: we learn from another tablet that the + various classes of evil spirits troubled different parts of the body; some + injured the head, some the hands and the feet, etc., therefore the passage + before may mean "the spirits whose power is over the hand shall loose + their hands from his," etc. "But," concludes Talbot, "I can offer no + decided opinion upon such obscure points of their superstition."(15) + </p> + <p> + In regard to evil spirits, as elsewhere, the number seven had a peculiar + significance, it being held that that number of spirits might enter into a + man together. Talbot has translated(16) a "wild chant" which he names "The + Song of the Seven Spirits." + </p> +<pre xml:space="preserve"> + 1. There are seven! There are seven! + 2. In the depths of the ocean there are seven! + 3. In the heights of the heaven there are seven! + 4. In the ocean stream in a palace they were born. + 5. Male they are not: female they are not! + 6. Wives they have not! Children are not born to them! + 7. Rules they have not! Government they know not! + 8. Prayers they hear not! + 9. There are seven! There are seven! Twice over there are +seven! +</pre> + <p> + The tablets make frequent allusion to these seven spirits. One starts + thus: + </p> +<pre xml:space="preserve"> + 1. The god (—-) shall stand by his bedside; + 2. These seven evil spirits he shall root out and shall expel +them from his body, 3. and these seven shall never return to the sick man +again.(17) +</pre> + <p> + Altogether similar are the exorcisms intended to ward off disease. + Professor Sayce has published translations of some of these.(18) Each of + these ends with the same phrase, and they differ only in regard to the + particular maladies from which freedom is desired. One reads: + </p> + <p> + "From wasting, from want of health, from the evil spirit of the ulcer, + from the spreading quinsy of the gullet, from the violent ulcer, from the + noxious ulcer, may the king of heaven preserve, may the king of earth + preserve." + </p> + <p> + Another is phrased thus: + </p> + <p> + "From the cruel spirit of the head, from the strong spirit of the head, + from the head spirit that departs not, from the head spirit that comes not + forth, from the head spirit that will not go, from the noxious head + spirit, may the king of heaven preserve, may the king of earth preserve." + </p> + <p> + As to omens having to do with the affairs of everyday life the number is + legion. For example, Moppert has published, in the Journal Asiatique,(19) + the translation of a tablet which contains on its two sides several scores + of birth-portents, a few of which maybe quoted at random: + </p> + <p> + "When a woman bears a child and it has the ears of a lion, a strong king + is in the country." "When a woman bears a child and it has a bird's beak, + that country is oppressed." "When a woman bears a child and its right hand + is wanting, that country goes to destruction." "When a woman bears a child + and its feet are wanting, the roads of the country are cut; that house is + destroyed." "When a woman bears a child and at the time of its birth its + beard is grown, floods are in the country." "When a woman bears a child + and at the time of its birth its mouth is open and speaks, there is + pestilence in the country, the Air-god inundates the crops of the country, + injury in the country is caused." + </p> + <p> + Some of these portents, it will be observed, are not in much danger of + realization, and it is curious to surmise by what stretch of the + imagination they can have been invented. There is, for example, on the + same tablet just quoted, one reference which assures us that "when a sheep + bears a lion the forces march multitudinously; the king has not a rival." + There are other omens, however, that are so easy of realization as to lead + one to suppose that any Babylonian who regarded all the superstitious + signs must have been in constant terror. Thus a tablet translated by + Professor Sayce(20) gives a long list of omens furnished by dogs, in which + we are assured that: + </p> +<pre xml:space="preserve"> + 1. If a yellow dog enters into the palace, exit from that + palace will be baleful. + 2. If a dog to the palace goes, and on a throne lies down, that + palace is burned. + 3. If a black dog into a temple enters, the foundation of that + temple is not stable. + 4. If female dogs one litter bear, destruction to the city. +</pre> + <p> + It is needless to continue these citations, since they but reiterate + endlessly the same story. It is interesting to recall, however, that the + observations of animate nature, which were doubtless superstitious in + their motive, had given the Babylonians some inklings of a knowledge of + classification. Thus, according to Menant,(21) some of the tablets from + Nineveh, which are written, as usual, in both the Sumerian and Assyrian + languages, and which, therefore, like practically all Assyrian books, draw + upon the knowledge of old Babylonia, give lists of animals, making an + attempt at classification. The dog, lion, and wolf are placed in one + category; the ox, sheep, and goat in another; the dog family itself is + divided into various races, as the domestic dog, the coursing dog, the + small dog, the dog of Elan, etc. Similar attempts at classification of + birds are found. Thus, birds of rapid flight, sea-birds, and marsh-birds + are differentiated. Insects are classified according to habit; those that + attack plants, animals, clothing, or wood. Vegetables seem to be + classified according to their usefulness. One tablet enumerates the uses + of wood according to its adaptability for timber-work of palaces, or + construction of vessels, the making of implements of husbandry, or even + furniture. Minerals occupy a long series in these tablets. They are + classed according to their qualities, gold and silver occupying a division + apart; precious stones forming another series. Our Babylonians, then, must + be credited with the development of a rudimentary science of natural + history. + </p> + <p> + BABYLONIAN MEDICINE + </p> + <p> + We have just seen that medical practice in the Babylonian world was + strangely under the cloud of superstition. But it should be understood + that our estimate, through lack of correct data, probably does much less + than justice to the attainments of the physician of the time. As already + noted, the existing tablets chance not to throw much light on the subject. + It is known, however, that the practitioner of medicine occupied a + position of some, authority and responsibility. The proof of this is found + in the clauses relating to the legal status of the physician which are + contained in the now famous code(22) of the Babylonian King Khamurabi, who + reigned about 2300 years before our era. These clauses, though throwing no + light on the scientific attainments of the physician of the period, are + too curious to be omitted. They are clauses 215 to 227 of the celebrated + code, and are as follows: + </p> + <p> + 215. If a doctor has treated a man for a severe wound with a lancet of + bronze and has cured the man, or has opened a tumor with a bronze lancet + and has cured the man's eye, he shall receive ten shekels of silver. + </p> + <p> + 216. If it was a freedman, he shall receive five shekels of silver. + </p> + <p> + 217. If it was a man's slave, the owner of the slave shall give the doctor + two shekels of silver. + </p> + <p> + 218. If a physician has treated a free-born man for a severe wound with a + lancet of bronze and has caused the man to die, or has opened a tumor of + the man with a lancet of bronze and has destroyed his eye, his hands one + shall cut off. + </p> + <p> + 219. If the doctor has treated the slave of a freedman for a severe wound + with a bronze lancet and has caused him to die, he shall give back slave + for slave. + </p> + <p> + 220. If he has opened his tumor with a bronze lancet and has ruined his + eye, he shall pay the half of his price in money. + </p> + <p> + 221. If a doctor has cured the broken limb of a man, or has healed his + sick body, the patient shall pay the doctor five shekels of silver. + </p> + <p> + 222. If it was a freedman, he shall give three shekels of silver. + </p> + <p> + 223. If it was a man's slave, the owner of the slave shall give two + shekels of silver to the doctor. + </p> + <p> + 224. If the doctor of oxen and asses has treated an ox or an ass for a + grave wound and has cured it, the owner of the ox or the ass shall give to + the doctor as his pay one-sixth of a shekel of silver. + </p> + <p> + 225. If he has treated an ox or an ass for a severe wound and has caused + its death, he shall pay one-fourth of its price to the owner of the ox or + the ass. + </p> + <p> + 226. If a barber-surgeon, without consent of the owner of a slave, has + branded the slave with an indelible mark, one shall cut off the hands of + that barber. + </p> + <p> + 227. If any one deceive the surgeon-barber and make him brand a slave with + an indelible mark, one shall kill that man and bury him in his house. The + barber shall swear, "I did not mark him wittingly," and he shall be + guiltless. + </p> + <p> + ESTIMATES OF BABYLONIAN SCIENCE + </p> + <p> + Before turning from the Oriental world it is perhaps worth while to + attempt to estimate somewhat specifically the world-influence of the name, + Babylonian science. Perhaps we cannot better gain an idea as to the + estimate put upon that science by the classical world than through a + somewhat extended quotation from a classical author. Diodorus Siculus, + who, as already noted, lived at about the time of Augustus, and who, + therefore, scanned in perspective the entire sweep of classical Greek + history, has left us a striking summary which is doubly valuable because + of its comparisons of Babylonian with Greek influence. Having viewed the + science of Babylonia in the light of the interpretations made possible by + the recent study of original documents, we are prepared to draw our own + conclusions from the statements of the Greek historian. Here is his + estimate in the words of the quaint translation made by Philemon Holland + in the year 1700:(23) + </p> + <p> + "They being the most ancient Babylonians, hold the same station and + dignity in the Common-wealth as the Egyptian Priests do in Egypt: For + being deputed to Divine Offices, they spend all their Time in the study of + Philosophy, and are especially famous for the Art of Astrology. They are + mightily given to Divination, and foretel future Events, and imploy + themselves either by Purifications, Sacrifices, or other Inchantments to + avert Evils, or procure good Fortune and Success. They are skilful + likewise in the Art of Divination, by the flying of Birds, and + interpreting of Dreams and Prodigies: And are reputed as true Oracles (in + declaring what will come to pass) by their exact and diligent viewing the + Intrals of the Sacrifices. But they attain not to this Knowledge in the + same manner as the Grecians do; for the Chaldeans learn it by Tradition + from their Ancestors, the Son from the Father, who are all in the mean + time free from all other publick Offices and Attendances; and because + their Parents are their Tutors, they both learn every thing without Envy, + and rely with more confidence upon the truth of what is taught them; and + being train'd up in this Learning, from their very Childhood, they become + most famous Philosophers, (that Age being most capable of Learning, + wherein they spend much of their time). But the Grecians for the most part + come raw to this study, unfitted and unprepar'd, and are long before they + attain to the Knowledge of this Philosophy: And after they have spent some + small time in this Study, they are many times call'd off and forc'd to + leave it, in order to get a Livelihood and Subsistence. And although some, + few do industriously apply themselves to Philosophy, yet for the sake of + Gain, these very Men are opinionative, and ever and anon starting new and + high Points, and never fix in the steps of their Ancestors. But the + Barbarians keeping constantly close to the same thing, attain to a perfect + and distinct Knowledge in every particular. + </p> + <p> + "But the Grecians, cunningly catching at all Opportunities of Gain, make + new Sects and Parties, and by their contrary Opinions wrangling and + quarelling concerning the chiefest Points, lead their Scholars into a + Maze; and being uncertain and doubtful what to pitch upon for certain + truth, their Minds are fluctuating and in suspence all the days of their + Lives, and unable to give a certain assent unto any thing. For if any Man + will but examine the most eminent Sects of the Philosophers, he shall find + them much differing among themselves, and even opposing one another in the + most weighty parts of their Philosophy. But to return to the Chaldeans, + they hold that the World is eternal, which had neither any certain + Beginning, nor shall have any End; but all agree, that all things are + order'd, and this beautiful Fabrick is supported by a Divine Providence, + and that the Motions of the Heavens are not perform'd by chance and of + their own accord, but by a certain and determinate Will and Appointment of + the Gods. + </p> + <p> + "Therefore from a long observation of the Stars, and an exact Knowledge of + the motions and influences of every one of them, wherein they excel all + others, they fortel many things that are to come to pass. + </p> + <p> + "They say that the Five Stars which some call Planets, but they + Interpreters, are most worthy of Consideration, both for their motions and + their remarkable influences, especially that which the Grecians call + Saturn. The brightest of them all, and which often portends many and great + Events, they call Sol, the other Four they name Mars, Venus, Mercury, and + Jupiter, with our own Country Astrologers. They give the Name of + Interpreters to these Stars, because these only by a peculiar Motion do + portend things to come, and instead of Jupiters, do declare to Men + before-hand the good-will of the Gods; whereas the other Stars (not being + of the number of the Planets) have a constant ordinary motion. Future + Events (they say) are pointed at sometimes by their Rising, and sometimes + by their Setting, and at other times by their Colour, as may be + experienc'd by those that will diligently observe it; sometimes + foreshewing Hurricanes, at other times Tempestuous Rains, and then again + exceeding Droughts. By these, they say, are often portended the appearance + of Comets, Eclipses of the Sun and Moon, Earthquakes and all other the + various Changes and remarkable effects in the Air, boding good and bad, + not only to Nations in general, but to Kings and Private Persons in + particular. Under the course of these Planets, they say are Thirty Stars, + which they call Counselling Gods, half of whom observe what is done under + the Earth, and the other half take notice of the actions of Men upon the + Earth, and what is transacted in the Heavens. Once every Ten Days space + (they say) one of the highest Order of these Stars descends to them that + are of the lowest, like a Messenger sent from them above; and then again + another ascends from those below to them above, and that this is their + constant natural motion to continue for ever. The chief of these Gods, + they say, are Twelve in number, to each of which they attribute a Month, + and one Sign of the Twelve in the Zodiack. + </p> + <p> + "Through these Twelve Signs the Sun, Moon, and the other Five Planets run + their Course. The Sun in a Years time, and the Moon in the space of a + Month. To every one of the Planets they assign their own proper Courses, + which are perform'd variously in lesser or shorter time according as their + several motions are quicker or slower. These Stars, they say, have a great + influence both as to good and bad in Mens Nativities; and from the + consideration of their several Natures, may be foreknown what will befal + Men afterwards. As they foretold things to come to other Kings formerly, + so they did to Alexander who conquer'd Darius, and to his Successors + Antigonus and Seleucus Nicator; and accordingly things fell out as they + declar'd; which we shall relate particularly hereafter in a more + convenient time. They tell likewise private Men their Fortunes so + certainly, that those who have found the thing true by Experience, have + esteem'd it a Miracle, and above the reach of man to perform. Out of the + Circle of the Zodiack they describe Four and Twenty Stars, Twelve towards + the North Pole, and as many to the South. + </p> + <p> + "Those which we see, they assign to the living; and the other that do not + appear, they conceive are Constellations for the Dead; and they term them + Judges of all things. The Moon, they say, is in the lowest Orb; and being + therefore next to the Earth (because she is so small), she finishes her + Course in a little time, not through the swiftness of her Motion, but the + shortness of her Sphear. In that which they affirm (that she has but a + borrow'd light, and that when she is eclips'd, it's caus'd by the + interposition of the shadow of the Earth) they agree with the Grecians. + </p> + <p> + "Their Rules and Notions concerning the Eclipses of the Sun are but weak + and mean, which they dare not positively foretel, nor fix a certain time + for them. They have likewise Opinions concerning the Earth peculiar to + themselves, affirming it to resemble a Boat, and to be hollow, to prove + which, and other things relating to the frame of the World, they abound in + Arguments; but to give a particular Account of 'em, we conceive would be a + thing foreign to our History. But this any Man may justly and truly say, + That the Chaldeans far exceed all other Men in the Knowledge of Astrology, + and have study'd it most of any other Art or Science: But the number of + years during which the Chaldeans say, those of their Profession have given + themselves to the study of this natural Philosophy, is incredible; for + when Alexander was in Asia, they reckon'd up Four Hundred and Seventy + Thousand Years since they first began to observe the Motions of the + Stars." + </p> + <p> + Let us now supplement this estimate of Babylonian influence with another + estimate written in our own day, and quoted by one of the most recent + historians of Babylonia and Assyria.(24) The estimate in question is that + of Canon Rawlinson in his Great Oriental Monarchies.(25) Of Babylonia he + says: + </p> + <p> + "Hers was apparently the genius which excogitated an alphabet; worked out + the simpler problems of arithmetic; invented implements for measuring the + lapse of time; conceived the idea of raising enormous structures with the + poorest of all materials, clay; discovered the art of polishing, boring, + and engraving gems; reproduced with truthfulness the outlines of human and + animal forms; attained to high perfection in textile fabrics; studied with + success the motions of the heavenly bodies; conceived of grammar as a + science; elaborated a system of law; saw the value of an exact chronology—in + almost every branch of science made a beginning, thus rendering it + comparatively easy for other nations to proceed with the + superstructure.... It was from the East, not from Egypt, that Greece + derived her architecture, her sculpture, her science, her philosophy, her + mathematical knowledge—in a word, her intellectual life. And Babylon + was the source to which the entire stream of Eastern civilization may be + traced. It is scarcely too much to say that, but for Babylon, real + civilization might not yet have dawned upon the earth." + </p> + <p> + Considering that a period of almost two thousand years separates the times + of writing of these two estimates, the estimates themselves are singularly + in unison. They show that the greatest of Oriental nations has not + suffered in reputation at the hands of posterity. It is indeed almost + impossible to contemplate the monuments of Babylonian and Assyrian + civilization that are now preserved in the European and American museums + without becoming enthusiastic. That certainly was a wonderful civilization + which has left us the tablets on which are inscribed the laws of a + Khamurabi on the one hand, and the art treasures of the palace of an + Asshurbanipal on the other. Yet a candid consideration of the scientific + attainments of the Babylonians and Assyrians can scarcely arouse us to a + like enthusiasm. In considering the subject we have seen that, so far as + pure science is concerned, the efforts of the Babylonians and Assyrians + chiefly centred about the subjects of astrology and magic. With the + records of their ghost-haunted science fresh in mind, one might be + forgiven for a momentary desire to take issue with Canon Rawlinson's + words. We are assured that the scientific attainments of Europe are almost + solely to be credited to Babylonia and not to Egypt, but we should not + forget that Plato, the greatest of the Greek thinkers, went to Egypt and + not to Babylonia to pursue his studies when he wished to penetrate the + secrets of Oriental science and philosophy. Clearly, then, classical + Greece did not consider Babylonia as having a monopoly of scientific + knowledge, and we of to-day, when we attempt to weigh the new evidence + that has come to us in recent generations with the Babylonian records + themselves, find that some, at least, of the heritages for which Babylonia + has been praised are of more than doubtful value. Babylonia, for example, + gave us our seven-day week and our system of computing by twelves. But + surely the world could have got on as well without that magic number + seven; and after some hundreds of generations we are coming to feel that + the decimal system of the Egyptians has advantages over the duodecimal + system of the Babylonians. Again, the Babylonians did not invent the + alphabet; they did not even accept it when all the rest of the world had + recognized its value. In grammar and arithmetic, as with astronomy, they + seemed not to have advanced greatly, if at all, upon the Egyptians. One + field in which they stand out in startling pre-eminence is the field of + astrology; but this, in the estimate of modern thought, is the very + negation of science. Babylonia impressed her superstitions on the Western + world, and when we consider the baleful influence of these superstitions, + we may almost question whether we might not reverse Canon Rawlinson's + estimate and say that perhaps but for Babylonia real civilization, based + on the application of true science, might have dawned upon the earth a + score of centuries before it did. Yet, after all, perhaps this estimate is + unjust. Society, like an individual organism, must creep before it can + walk, and perhaps the Babylonian experiments in astrology and magic, which + European civilization was destined to copy for some three or four thousand + years, must have been made a part of the necessary evolution of our race + in one place or in another. That thought, however, need not blind us to + the essential fact, which the historian of science must needs admit, that + for the Babylonian, despite his boasted culture, science spelled + superstition. + </p> + <p> + <a name="link2H_4_0006" id="link2H_4_0006"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + IV. THE DEVELOPMENT OF THE ALPHABET + </h2> + <p> + Before we turn specifically to the new world of the west, it remains to + take note of what may perhaps be regarded as the very greatest achievement + of ancient science. This was the analysis of speech sounds, and the + resulting development of a system of alphabetical writing. To comprehend + the series of scientific inductions which led to this result, we must go + back in imagination and trace briefly the development of the methods of + recording thought by means of graphic symbols. In other words, we must + trace the evolution of the art of writing. In doing so we cannot hold to + national lines as we have done in the preceding two chapters, though the + efforts of the two great scientific nations just considered will enter + prominently into the story. + </p> + <p> + The familiar Greek legend assures us that a Phoenician named Kadmus was + the first to bring a knowledge of letters into Europe. An elaboration of + the story, current throughout classical times, offered the further + explanation that the Phoenicians had in turn acquired the art of writing + from the Egyptians or Babylonians. Knowledge as to the true origin and + development of the art of writing did not extend in antiquity beyond such + vagaries as these. Nineteenth-century studies gave the first real clews to + an understanding of the subject. These studies tended to authenticate the + essential fact on which the legend of Kadmus was founded; to the extent, + at least, of making it probable that the later Grecian alphabet was + introduced from Phoenicia—though not, of course, by any individual + named Kadmus, the latter being, indeed, a name of purely Greek origin. + Further studies of the past generation tended to corroborate the ancient + belief as to the original source of the Phoenician alphabet, but divided + scholars between two opinions: the one contending that the Egyptian + hieroglyphics were the source upon which the Phoenicians drew; and the + other contending with equal fervor that the Babylonian wedge character + must be conceded that honor. + </p> + <p> + But, as has often happened in other fields after years of acrimonious + controversy, a new discovery or two may suffice to show that neither + contestant was right. After the Egyptologists of the school of De Rouge(1) + thought they had demonstrated that the familiar symbols of the Phoenician + alphabet had been copied from that modified form of Egyptian hieroglyphics + known as the hieratic writing, the Assyriologists came forward to prove + that certain characters of the Babylonian syllabary also show a likeness + to the alphabetical characters that seemingly could not be due to chance. + And then, when a settlement of the dispute seemed almost hopeless, it was + shown through the Egyptian excavations that characters even more closely + resembling those in dispute had been in use all about the shores of the + Mediterranean, quite independently of either Egyptian or Assyrian + writings, from periods so ancient as to be virtually prehistoric. + </p> + <p> + Coupled with this disconcerting discovery are the revelations brought to + light by the excavations at the sites of Knossos and other long-buried + cities of the island of Crete.(2) These excavations, which are still in + progress, show that the art of writing was known and practised + independently in Crete before that cataclysmic overthrow of the early + Greek civilization which archaeologists are accustomed to ascribe to the + hypothetical invasion of the Dorians. The significance of this is that the + art of writing was known in Europe long before the advent of the mythical + Kadmus. But since the early Cretan scripts are not to be identified with + the scripts used in Greece in historical times, whereas the latter are + undoubtedly of lineal descent from the Phoenician alphabet, the validity + of the Kadmus legend, in a modified form, must still be admitted. + </p> + <p> + As has just been suggested, the new knowledge, particularly that which + related to the great antiquity of characters similar to the Phoenician + alphabetical signs, is somewhat disconcerting. Its general trend, however, + is quite in the same direction with most of the new archaeological + knowledge of recent decades—-that is to say, it tends to emphasize + the idea that human civilization in most of its important elaborations is + vastly older than has hitherto been supposed. It may be added, however, + that no definite clews are as yet available that enable us to fix even an + approximate date for the origin of the Phoenician alphabet. The signs, to + which reference has been made, may well have been in existence for + thousands of years, utilized merely as property marks, symbols for + counting and the like, before the idea of setting them aside as phonetic + symbols was ever conceived. Nothing is more certain, in the judgment of + the present-day investigator, than that man learned to write by slow and + painful stages. It is probable that the conception of such an analysis of + speech sounds as would make the idea of an alphabet possible came at a + very late stage of social evolution, and as the culminating achievement of + a long series of improvements in the art of writing. The precise steps + that marked this path of intellectual development can for the most part be + known only by inference; yet it is probable that the main chapters of the + story may be reproduced with essential accuracy. + </p> + <p> + FIRST STEPS + </p> + <p> + For the very first chapters of the story we must go back in imagination to + the prehistoric period. Even barbaric man feels the need of + self-expression, and strives to make his ideas manifest to other men by + pictorial signs. The cave-dwellers scratched pictures of men and animals + on the surface of a reindeer horn or mammoth tusk as mementos of his + prowess. The American Indian does essentially the same thing to-day, + making pictures that crudely record his successes in war and the chase. + The Northern Indian had got no farther than this when the white man + discovered America; but the Aztecs of the Southwest and the Maya people of + Yucatan had carried their picture-making to a much higher state of + elaboration.(3) They had developed systems of pictographs or hieroglyphics + that would doubtless in the course of generations have been elaborated + into alphabetical systems, had not the Europeans cut off the civilization + of which they were the highest exponents. + </p> + <p> + What the Aztec and Maya were striving towards in the sixteenth century + A.D., various Oriental nations had attained at least five or six thousand + years earlier. In Egypt at the time of the pyramid-builders, and in + Babylonia at the same epoch, the people had developed systems of writing + that enabled them not merely to present a limited range of ideas + pictorially, but to express in full elaboration and with finer shades of + meaning all the ideas that pertain to highly cultured existence. The man + of that time made records of military achievements, recorded the + transactions of every-day business life, and gave expression to his moral + and spiritual aspirations in a way strangely comparable to the manner of + our own time. He had perfected highly elaborate systems of writing. + </p> + <p> + EGYPTIAN WRITING + </p> + <p> + Of the two ancient systems of writing just referred to as being in vogue + at the so-called dawnings of history, the more picturesque and suggestive + was the hieroglyphic system of the Egyptians. This is a curiously + conglomerate system of writing, made up in part of symbols reminiscent of + the crudest stages of picture-writing, in part of symbols having the + phonetic value of syllables, and in part of true alphabetical letters. In + a word, the Egyptian writing represents in itself the elements of the + various stages through which the art of writing has developed.(4) We must + conceive that new features were from time to time added to it, while the + old features, curiously enough, were not given up. + </p> + <p> + Here, for example, in the midst of unintelligible lines and pot-hooks, are + various pictures that are instantly recognizable as representations of + hawks, lions, ibises, and the like. It can hardly be questioned that when + these pictures were first used calligraphically they were meant to + represent the idea of a bird or animal. In other words, the first stage of + picture-writing did not go beyond the mere representation of an eagle by + the picture of an eagle. But this, obviously, would confine the + presentation of ideas within very narrow limits. In due course some + inventive genius conceived the thought of symbolizing a picture. To him + the outline of an eagle might represent not merely an actual bird, but the + thought of strength, of courage, or of swift progress. Such a use of + symbols obviously extends the range of utility of a nascent art of + writing. Then in due course some wonderful psychologist—or perhaps + the joint efforts of many generations of psychologists—made the + astounding discovery that the human voice, which seems to flow on in an + unbroken stream of endlessly varied modulations and intonations, may + really be analyzed into a comparatively limited number of component sounds—into + a few hundreds of syllables. That wonderful idea conceived, it was only a + matter of time until it would occur to some other enterprising genius that + by selecting an arbitrary symbol to represent each one of these elementary + sounds it would be possible to make a written record of the words of human + speech which could be reproduced—rephonated—by some one who + had never heard the words and did not know in advance what this written + record contained. This, of course, is what every child learns to do now in + the primer class, but we may feel assured that such an idea never occurred + to any human being until the peculiar forms of pictographic writing just + referred to had been practised for many centuries. Yet, as we have said, + some genius of prehistoric Egypt conceived the idea and put it into + practical execution, and the hieroglyphic writing of which the Egyptians + were in full possession at the very beginning of what we term the + historical period made use of this phonetic system along with the + ideographic system already described. + </p> + <p> + So fond were the Egyptians of their pictorial symbols used ideographically + that they clung to them persistently throughout the entire period of + Egyptian history. They used symbols as phonetic equivalents very + frequently, but they never learned to depend upon them exclusively. The + scribe always interspersed his phonetic signs with some other signs + intended as graphic aids. After spelling a word out in full, he added a + picture, sometimes even two or three pictures, representative of the + individual thing, or at least of the type of thing to which the word + belongs. Two or three illustrations will make this clear. + </p> + <p> + Thus qeften, monkey, is spelled out in full, but the picture of a monkey + is added as a determinative; second, qenu, cavalry, after being spelled, + is made unequivocal by the introduction of a picture of a horse; third, + temati, wings, though spelled elaborately, has pictures of wings added; + and fourth, tatu, quadrupeds, after being spelled, has a picture of a + quadruped, and then the picture of a hide, which is the usual + determinative of a quadruped, followed by three dashes to indicate the + plural number. + </p> + <p> + It must not be supposed, however, that it was a mere whim which led the + Egyptians to the use of this system of determinatives. There was sound + reason back of it. It amounted to no more than the expedient we adopt when + we spell "to," "two," or "too," in indication of a single sound with three + different meanings. The Egyptian language abounds in words having more + than one meaning, and in writing these it is obvious that some means of + distinction is desirable. The same thing occurs even more frequently in + the Chinese language, which is monosyllabic. The Chinese adopt a more + clumsy expedient, supplying a different symbol for each of the meanings of + a syllable; so that while the actual word-sounds of their speech are only + a few hundreds in number, the characters of their written language mount + high into the thousands. + </p> + <p> + BABYLONIAN WRITING + </p> + <p> + While the civilization of the Nile Valley was developing this + extraordinary system of hieroglyphics, the inhabitants of Babylonia were + practising the art of writing along somewhat different lines. It is + certain that they began with picture-making, and that in due course they + advanced to the development of the syllabary; but, unlike their Egyptian + cousins, the men of Babylonia saw fit to discard the old system when they + had perfected a better one.(5) So at a very early day their writing—as + revealed to us now through the recent excavations—had ceased to have + that pictorial aspect which distinguishes the Egyptian script. What had + originally been pictures of objects—fish, houses, and the like—had + come to be represented by mere aggregations of wedge-shaped marks. As the + writing of the Babvlonians was chiefly inscribed on soft clay, the + adaptation of this wedge-shaped mark in lieu of an ordinary line was + probably a mere matter of convenience, since the sharp-cornered implement + used in making the inscription naturally made a wedge-shaped impression in + the clay. That, however, is a detail. The essential thing is that the + Babylonian had so fully analyzed the speech-sounds that he felt entire + confidence in them, and having selected a sufficient number of + conventional characters—each made up of wedge-shaped lines—to + represent all the phonetic sounds of his language, spelled the words out + in syllables and to some extent dispensed with the determinative signs + which, as we have seen, played so prominent a part in the Egyptian + writing. His cousins the Assyrians used habitually a system of writing the + foundation of which was an elaborate phonetic syllabary; a system, + therefore, far removed from the old crude pictograph, and in some respects + much more developed than the complicated Egyptian method; yet, after all, + a system that stopped short of perfection by the wide gap that separates + the syllabary from the true alphabet. + </p> + <p> + A brief analysis of speech sounds will aid us in understanding the real + nature of the syllabary. Let us take for consideration the consonantal + sound represented by the letter b. A moment's consideration will make it + clear that this sound enters into a large number of syllables. There are, + for example, at least twenty vowel sounds in the English language, not to + speak of certain digraphs; that is to say, each of the important vowels + has from two to six sounds. Each of these vowel sounds may enter into + combination with the b sound alone to form three syllables; as ba, ab, + bal, be, eb, bel, etc. Thus there are at least sixty b-sound syllables. + But this is not the end, for other consonantal sounds may be associated in + the syllables in such combinations as bad, bed, bar, bark, cab, etc. As + each of the other twenty odd consonantal sounds may enter into similar + combinations, it is obvious that there are several hundreds of fundamental + syllables to be taken into account in any syllabic system of writing. For + each of these syllables a symbol must be set aside and held in reserve as + the representative of that particular sound. A perfect syllabary, then, + would require some hundred or more of symbols to represent b sounds alone; + and since the sounds for c, d, f, and the rest are equally varied, the + entire syllabary would run into thousands of characters, almost rivalling + in complexity the Chinese system. But in practice the most perfect + syllabary, Such as that of the Babylonians, fell short of this degree of + precision through ignoring the minor shades of sound; just as our own + alphabet is content to represent some thirty vowel sounds by five letters, + ignoring the fact that a, for example, has really half a dozen distinct + phonetic values. By such slurring of sounds the syllabary is reduced far + below its ideal limits; yet even so it retains three or four hundred + characters. + </p> + <p> + In point of fact, such a work as Professor Delitzsch's Assyrian Grammar(6) + presents signs for three hundred and thirty-four syllables, together with + sundry alternative signs and determinatives to tax the memory of the + would-be reader of Assyrian. Let us take for example a few of the b + sounds. It has been explained that the basis of the Assyrian written + character is a simple wedge-shaped or arrow-head mark. Variously repeated + and grouped, these marks make up the syllabic characters. + </p> + <p> + To learn some four hundred such signs as these was the task set, as an + equivalent of learning the a b c's, to any primer class in old Assyria in + the long generations when that land was the culture Centre of the world. + Nor was the task confined to the natives of Babylonia and Assyria alone. + About the fifteenth century B.C., and probably for a long time before and + after that period, the exceedingly complex syllabary of the Babylonians + was the official means of communication throughout western Asia and + between Asia and Egypt, as we know from the chance discovery of a + collection of letters belonging to the Egyptian king Khun-aten, preserved + at Tel-el-Amarna. In the time of Ramses the Great the Babylonian writing + was in all probability considered by a majority of the most highly + civilized people in the world to be the most perfect script practicable. + Doubtless the average scribe of the time did not in the least realize the + waste of energy involved in his labors, or ever suspect that there could + be any better way of writing. + </p> + <p> + Yet the analysis of any one of these hundreds of syllables into its + component phonetic elements—had any one been genius enough to make + such analysis—would have given the key to simpler and better things. + But such an analysis was very hard to make, as the sequel shows. Nor is + the utility of such an analysis self-evident, as the experience of the + Egyptians proved. The vowel sound is so intimately linked with the + consonant—the con-sonant, implying this intimate relation in its + very name—that it seemed extremely difficult to give it individual + recognition. To set off the mere labial beginning of the sound by itself, + and to recognize it as an all-essential element of phonation, was the feat + at which human intelligence so long balked. The germ of great things lay + in that analysis. It was a process of simplification, and all art + development is from the complex to the simple. Unfortunately, however, it + did not seem a simplification, but rather quite the reverse. We may well + suppose that the idea of wresting from the syllabary its secret of + consonants and vowels, and giving to each consonantal sound a distinct + sign, seemed a most cumbersome and embarrassing complication to the + ancient scholars—that is to say, after the time arrived when any one + gave such an idea expression. We can imagine them saying: "You will oblige + us to use four signs instead of one to write such an elementary syllable + as 'bard,' for example. Out upon such endless perplexity!" Nor is such a + suggestion purely gratuitous, for it is an historical fact that the old + syllabary continued to be used in Babylon hundreds of years after the + alphabetical system had been introduced.(7) Custom is everything in + establishing our prejudices. The Japanese to-day rebel against the + introduction of an alphabet, thinking it ambiguous. + </p> + <p> + Yet, in the end, conservatism always yields, and so it was with opposition + to the alphabet. Once the idea of the consonant had been firmly grasped, + the old syllabary was doomed, though generations of time might be required + to complete the obsequies—generations of time and the influence of a + new nation. We have now to inquire how and by whom this advance was made. + </p> + <p> + THE ALPHABET ACHIEVED + </p> + <p> + We cannot believe that any nation could have vaulted to the final stage of + the simple alphabetical writing without tracing the devious and difficult + way of the pictograph and the syllabary. It is possible, however, for a + cultivated nation to build upon the shoulders of its neighbors, and, + profiting by the experience of others, to make sudden leaps upward and + onward. And this is seemingly what happened in the final development of + the art of writing. For while the Babylonians and Assyrians rested content + with their elaborate syllabary, a nation on either side of them, + geographically speaking, solved the problem, which they perhaps did not + even recognize as a problem; wrested from their syllabary its secret of + consonants and vowels, and by adopting an arbitrary sign for each + consonantal sound, produced that most wonderful of human inventions, the + alphabet. + </p> + <p> + The two nations credited with this wonderful achievement are the + Phoenicians and the Persians. But it is not usually conceded that the two + are entitled to anything like equal credit. The Persians, probably in the + time of Cyrus the Great, used certain characters of the Babylonian script + for the construction of an alphabet; but at this time the Phoenician + alphabet had undoubtedly been in use for some centuries, and it is more + than probable that the Persian borrowed his idea of an alphabet from a + Phoenician source. And that, of course, makes all the difference. Granted + the idea of an alphabet, it requires no great reach of constructive genius + to supply a set of alphabetical characters; though even here, it may be + added parenthetically, a study of the development of alphabets will show + that mankind has all along had a characteristic propensity to copy rather + than to invent. + </p> + <p> + Regarding the Persian alphabet-maker, then, as a copyist rather than a + true inventor, it remains to turn attention to the Phoenician source + whence, as is commonly believed, the original alphabet which became "the + mother of all existing alphabets" came into being. It must be admitted at + the outset that evidence for the Phoenician origin of this alphabet is + traditional rather than demonstrative. The Phoenicians were the great + traders of antiquity; undoubtedly they were largely responsible for the + transmission of the alphabet from one part of the world to another, once + it had been invented. Too much credit cannot be given them for this; and + as the world always honors him who makes an idea fertile rather than the + originator of the idea, there can be little injustice in continuing to + speak of the Phoenicians as the inventors of the alphabet. But the actual + facts of the case will probably never be known. For aught we know, it may + have been some dreamy-eyed Israelite, some Babylonian philosopher, some + Egyptian mystic, perhaps even some obscure Cretan, who gave to the + hard-headed Phoenician trader this conception of a dismembered syllable + with its all-essential, elemental, wonder-working consonant. But it is + futile now to attempt even to surmise on such unfathomable details as + these. Suffice it that the analysis was made; that one sign and no more + was adopted for each consonantal sound of the Semitic tongue, and that the + entire cumbersome mechanism of the Egyptian and Babylonian writing systems + was rendered obsolescent. These systems did not yield at once, to be sure; + all human experience would have been set at naught had they done so. They + held their own, and much more than held their own, for many centuries. + After the Phoenicians as a nation had ceased to have importance; after + their original script had been endlessly modified by many alien nations; + after the original alphabet had made the conquest of all civilized Europe + and of far outlying portions of the Orient—the Egyptian and + Babylonian scribes continued to indite their missives in the same old + pictographs and syllables. + </p> + <p> + The inventive thinker must have been struck with amazement when, after + making the fullest analysis of speech-sounds of which he was capable, he + found himself supplied with only a score or so of symbols. Yet as regards + the consonantal sounds he had exhausted the resources of the Semitic + tongue. As to vowels, he scarcely considered them at all. It seemed to him + sufficient to use one symbol for each consonantal sound. This reduced the + hitherto complex mechanism of writing to so simple a system that the + inventor must have regarded it with sheer delight. On the other hand, the + conservative scholar doubtless thought it distinctly ambiguous. In truth, + it must be admitted that the system was imperfect. It was a vast + improvement on the old syllabary, but it had its drawbacks. Perhaps it had + been made a bit too simple; certainly it should have had symbols for the + vowel sounds as well as for the consonants. Nevertheless, the + vowel-lacking alphabet seems to have taken the popular fancy, and to this + day Semitic people have never supplied its deficiencies save with certain + dots and points. + </p> + <p> + Peoples using the Aryan speech soon saw the defect, and the Greeks + supplied symbols for several new sounds at a very early day.(8) But there + the matter rested, and the alphabet has remained imperfect. For the + purposes of the English language there should certainly have been added a + dozen or more new characters. It is clear, for example, that, in the + interest of explicitness, we should have a separate symbol for the vowel + sound in each of the following syllables: bar, bay, bann, ball, to cite a + single illustration. + </p> + <p> + There is, to be sure, a seemingly valid reason for not extending our + alphabet, in the fact that in multiplying syllables it would be difficult + to select characters at once easy to make and unambiguous. Moreover, the + conservatives might point out, with telling effect, that the present + alphabet has proved admirably effective for about three thousand years. + Yet the fact that our dictionaries supply diacritical marks for some + thirty vowels sounds to indicate the pronunciation of the words of our + every-day speech, shows how we let memory and guessing do the work that + might reasonably be demanded of a really complete alphabet. But, whatever + its defects, the existing alphabet is a marvellous piece of mechanism, the + result of thousands of years of intellectual effort. It is, perhaps + without exception, the most stupendous invention of the human intellect + within historical times—an achievement taking rank with such great + prehistoric discoveries as the use of articulate speech, the making of a + fire, and the invention of stone implements, of the wheel and axle, and of + picture-writing. It made possible for the first time that education of the + masses upon which all later progress of civilization was so largely to + depend. + </p> + <p> + <a name="link2H_4_0007" id="link2H_4_0007"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + V. THE BEGINNINGS OF GREEK SCIENCE + </h2> + <p> + Herodotus, the Father of History, tells us that once upon a time—which + time, as the modern computator shows us, was about the year 590 B.C.—a + war had risen between the Lydians and the Medes and continued five years. + "In these years the Medes often discomfited the Lydians and the Lydians + often discomfited the Medes (and among other things they fought a battle + by night); and yet they still carried on the war with equally balanced + fortitude. In the sixth year a battle took place in which it happened, + when the fight had begun, that suddenly the day became night. And this + change of the day Thales, the Milesian, had foretold to the Ionians, + laying down as a limit this very year in which the change took place. The + Lydians, however, and the Medes, when they saw that it had become night + instead of day, ceased from their fighting and were much more eager, both + of them, that peace should be made between them." + </p> + <p> + This memorable incident occurred while Alyattus, father of Croesus, was + king of the Lydians. The modern astronomer, reckoning backward, estimates + this eclipse as occurring probably May 25th, 585 B.C. The date is + important as fixing a mile-stone in the chronology of ancient history, but + it is doubly memorable because it is the first recorded instance of a + predicted eclipse. Herodotus, who tells the story, was not born until + about one hundred years after the incident occurred, but time had not + dimmed the fame of the man who had performed the necromantic feat of + prophecy. Thales, the Milesian, thanks in part at least to this + accomplishment, had been known in life as first on the list of the Seven + Wise Men of Greece, and had passed into history as the father of Greek + philosophy. We may add that he had even found wider popular fame through + being named by Hippolytus, and then by Father aesop, as the philosopher + who, intent on studying the heavens, fell into a well; "whereupon," says + Hippolytus, "a maid-servant named Thratta laughed at him and said, 'In his + search for things in the sky he does not see what is at his feet.'" + </p> + <p> + Such citations as these serve to bring vividly to mind the fact that we + are entering a new epoch of thought. Hitherto our studies have been + impersonal. Among Egyptians and Babylonians alike we have had to deal with + classes of scientific records, but we have scarcely come across a single + name. Now, however, we shall begin to find records of the work of + individual investigators. In general, from now on, we shall be able to + trace each great idea, if not to its originator, at least to some one man + of genius who was prominent in bringing it before the world. The first of + these vitalizers of thought, who stands out at the beginnings of Greek + history, is this same Thales, of Miletus. His is not a very sharply + defined personality as we look back upon it, and we can by no means be + certain that all the discoveries which are ascribed to him are + specifically his. Of his individuality as a man we know very little. It is + not even quite certain as to where he was born; Miletus is usually + accepted as his birthplace, but one tradition makes him by birth a + Phenician. It is not at all in question, however, that by blood he was at + least in part an Ionian Greek. It will be recalled that in the seventh + century B.C., when Thales was born—and for a long time thereafter—the + eastern shores of the aegean Sea were quite as prominently the centre of + Greek influence as was the peninsula of Greece itself. Not merely Thales, + but his followers and disciples, Anaximander and Anaximenes, were born + there. So also was Herodotas, the Father of History, not to extend the + list. There is nothing anomalous, then, in the fact that Thales, the + father of Greek thought, was born and passed his life on soil that was not + geographically a part of Greece; but the fact has an important + significance of another kind. Thanks to his environment, Thales was + necessarily brought more or less in contact with Oriental ideas. There was + close commercial contact between the land of his nativity and the great + Babylonian capital off to the east, as also with Egypt. Doubtless this + association was of influence in shaping the development of Thales's mind. + Indeed, it was an accepted tradition throughout classical times that the + Milesian philosopher had travelled in Egypt, and had there gained at least + the rudiments of his knowledge of geometry. In the fullest sense, then, + Thales may be regarded as representing a link in the chain of thought + connecting the learning of the old Orient with the nascent scholarship of + the new Occident. Occupying this position, it is fitting that the + personality of Thales should partake somewhat of mystery; that the scene + may not be shifted too suddenly from the vague, impersonal East to the + individualism of Europe. + </p> + <p> + All of this, however, must not be taken as casting any doubt upon the + existence of Thales as a real person. Even the dates of his life—640 + to 546 B.C.—may be accepted as at least approximately trustworthy; + and the specific discoveries ascribed to him illustrate equally well the + stage of development of Greek thought, whether Thales himself or one of + his immediate disciples were the discoverer. We have already mentioned the + feat which was said to have given Thales his great reputation. That Thales + was universally credited with having predicted the famous eclipse is + beyond question. That he actually did predict it in any precise sense of + the word is open to doubt. At all events, his prediction was not based + upon any such precise knowledge as that of the modern astronomer. There + is, indeed, only one way in which he could have foretold the eclipse, and + that is through knowledge of the regular succession of preceding eclipses. + But that knowledge implies access on the part of some one to long series + of records of practical observations of the heavens. Such records, as we + have seen, existed in Egypt and even more notably in Babylonia. That these + records were the source of the information which established the + reputation of Thales is an unavoidable inference. In other words, the + magical prevision of the father of Greek thought was but a reflex of + Oriental wisdom. Nevertheless, it sufficed to establish Thales as the + father of Greek astronomy. In point of fact, his actual astronomical + attainments would appear to have been meagre enough. There is nothing to + show that he gained an inkling of the true character of the solar system. + He did not even recognize the sphericity of the earth, but held, still + following the Oriental authorities, that the world is a flat disk. Even + his famous cosmogonic guess, according to which water is the essence of + all things and the primordial element out of which the earth was + developed, is but an elaboration of the Babylonian conception. + </p> + <p> + When we turn to the other field of thought with which the name of Thales + is associated—namely, geometry—we again find evidence of the + Oriental influence. The science of geometry, Herodotus assures us, was + invented in Egypt. It was there an eminently practical science, being + applied, as the name literally suggests, to the measurement of the earth's + surface. Herodotus tells us that the Egyptians were obliged to cultivate + the science because the periodical inundations washed away the + boundary-lines between their farms. The primitive geometer, then, was a + surveyor. The Egyptian records, as now revealed to us, show that the + science had not been carried far in the land of its birth. The Egyptian + geometer was able to measure irregular pieces of land only approximately. + He never fully grasped the idea of the perpendicular as the true index of + measurement for the triangle, but based his calculations upon measurements + of the actual side of that figure. Nevertheless, he had learned to square + the circle with a close approximation to the truth, and, in general, his + measurement sufficed for all his practical needs. Just how much of the + geometrical knowledge which added to the fame of Thales was borrowed + directly from the Egyptians, and how much he actually created we cannot be + sure. Nor is the question raised in disparagement of his genius. + Receptivity is the first prerequisite to progressive thinking, and that + Thales reached out after and imbibed portions of Oriental wisdom argues in + itself for the creative character of his genius. Whether borrower of + originator, however, Thales is credited with the expression of the + following geometrical truths: + </p> + <p> + 1. That the circle is bisected by its diameter. + </p> + <p> + 2. That the angles at the base of an isosceles triangle are equal. + </p> + <p> + 3. That when two straight lines cut each other the vertical opposite + angles are equal. + </p> + <p> + 4. That the angle in a semicircle is a right angle. + </p> + <p> + 5. That one side and one acute angle of a right-angle triangle determine + the other sides of the triangle. + </p> + <p> + It was by the application of the last of these principles that Thales is + said to have performed the really notable feat of measuring the distance + of a ship from the shore, his method being precisely the same in principle + as that by which the guns are sighted on a modern man-of-war. Another + practical demonstration which Thales was credited with making, and to + which also his geometrical studies led him, was the measurement of any + tall object, such as a pyramid or building or tree, by means of its + shadow. The method, though simple enough, was ingenious. It consisted + merely in observing the moment of the day when a perpendicular stick casts + a shadow equal to its own length. Obviously the tree or monument would + also cast a shadow equal to its own height at the same moment. It remains + then but to measure the length of this shadow to determine the height of + the object. Such feats as this evidence the practicality of the genius of + Thales. They suggest that Greek science, guided by imagination, was + starting on the high-road of observation. We are told that Thales + conceived for the first time the geometry of lines, and that this, indeed, + constituted his real advance upon the Egyptians. We are told also that he + conceived the eclipse of the sun as a purely natural phenomenon, and that + herein lay his advance upon the Chaldean point of view. But if this be + true Thales was greatly in advance of his time, for it will be recalled + that fully two hundred years later the Greeks under Nicias before Syracuse + were so disconcerted by the appearance of an eclipse, which was + interpreted as a direct omen and warning, that Nicias threw away the last + opportunity to rescue his army. Thucydides, it is true, in recording this + fact speaks disparagingly of the superstitious bent of the mind of Nicias, + but Thucydides also was a man far in advance of his time. + </p> + <p> + All that we know of the psychology of Thales is summed up in the famous + maxim, "Know thyself," a maxim which, taken in connection with the proven + receptivity of the philosopher's mind, suggests to us a marvellously + rounded personality. + </p> + <p> + The disciples or successors of Thales, Anaximander and Anaximenes, were + credited with advancing knowledge through the invention or introduction of + the sundial. We may be sure, however, that the gnomon, which is the + rudimentary sundial, had been known and used from remote periods in the + Orient, and the most that is probable is that Anaximander may have + elaborated some special design, possibly the bowl-shaped sundial, through + which the shadow of the gnomon would indicate the time. The same + philosopher is said to have made the first sketch of a geographical map, + but this again is a statement which modern researches have shown to be + fallacious, since a Babylonian attempt at depicting the geography of the + world is still preserved to us on a clay tablet. Anaximander may, however, + have been the first Greek to make an attempt of this kind. Here again the + influence of Babylonian science upon the germinating Western thought is + suggested. + </p> + <p> + It is said that Anaximander departed from Thales's conception of the + earth, and, it may be added, from the Babylonian conception also, in that + he conceived it as a cylinder, or rather as a truncated cone, the upper + end of which is the habitable portion. This conception is perhaps the + first of these guesses through which the Greek mind attempted to explain + the apparent fixity of the earth. To ask what supports the earth in space + is most natural, but the answer given by Anaximander, like that more + familiar Greek solution which transformed the cone, or cylinder, into the + giant Atlas, is but another illustration of that substitution of + unwarranted inference for scientific induction which we have already so + often pointed out as characteristic of the primitive stages of thought. + </p> + <p> + Anaximander held at least one theory which, as vouched for by various + copyists and commentators, entitles him to be considered perhaps the first + teacher of the idea of organic evolution. According to this idea, man + developed from a fishlike ancestor, "growing up as sharks do until able to + help himself and then coming forth on dry land."(1) The thought here + expressed finds its germ, perhaps, in the Babylonian conception that + everything came forth from a chaos of waters. Yet the fact that the + thought of Anaximander has come down to posterity through such various + channels suggests that the Greek thinker had got far enough away from the + Oriental conception to make his view seem to his contemporaries a novel + and individual one. Indeed, nothing we know of the Oriental line of + thought conveys any suggestion of the idea of transformation of species, + whereas that idea is distinctly formulated in the traditional views of + Anaximander. + </p> + <p> + <a name="link2H_4_0008" id="link2H_4_0008"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + </h2> + <p> + Diogenes Laertius tells a story about a youth who, clad in a purple toga, + entered the arena at the Olympian games and asked to compete with the + other youths in boxing. He was derisively denied admission, presumably + because he was beyond the legitimate age for juvenile contestants. Nothing + daunted, the youth entered the lists of men, and turned the laugh on his + critics by coming off victor. The youth who performed this feat was named + Pythagoras. He was the same man, if we may credit the story, who + afterwards migrated to Italy and became the founder of the famous + Crotonian School of Philosophy; the man who developed the religion of the + Orphic mysteries; who conceived the idea of the music of the spheres; who + promulgated the doctrine of metempsychosis; who first, perhaps, of all men + clearly conceived the notion that this world on which we live is a ball + which moves in space and which may be habitable on every side. + </p> + <p> + A strange development that for a stripling pugilist. But we must not + forget that in the Greek world athletics held a peculiar place. The chief + winner of Olympian games gave his name to an epoch (the ensuing Olympiad + of four years), and was honored almost before all others in the land. A + sound mind in a sound body was the motto of the day. To excel in feats of + strength and dexterity was an accomplishment that even a philosopher need + not scorn. It will be recalled that aeschylus distinguished himself at the + battle of Marathon; that Thucydides, the greatest of Greek historians, was + a general in the Peloponnesian War; that Xenophon, the pupil and + biographer of Socrates, was chiefly famed for having led the Ten Thousand + in the memorable campaign of Cyrus the Younger; that Plato himself was + credited with having shown great aptitude in early life as a wrestler. If, + then, Pythagoras the philosopher was really the Pythagoras who won the + boxing contest, we may suppose that in looking back upon this athletic + feat from the heights of his priesthood—for he came to be almost + deified—he regarded it not as an indiscretion of his youth, but as + one of the greatest achievements of his life. Not unlikely he recalled + with pride that he was credited with being no less an innovator in + athletics than in philosophy. At all events, tradition credits him with + the invention of "scientific" boxing. Was it he, perhaps, who taught the + Greeks to strike a rising and swinging blow from the hip, as depicted in + the famous metopes of the Parthenon? If so, the innovation of Pythagoras + was as little heeded in this regard in a subsequent age as was his theory + of the motion of the earth; for to strike a swinging blow from the hip, + rather than from the shoulder, is a trick which the pugilist learned anew + in our own day. + </p> + <p> + But enough of pugilism and of what, at best, is a doubtful tradition. Our + concern is with another "science" than that of the arena. We must follow + the purple-robed victor to Italy—if, indeed, we be not + over-credulous in accepting the tradition—and learn of triumphs of a + different kind that have placed the name of Pythagoras high on the list of + the fathers of Grecian thought. To Italy? Yes, to the western limits of + the Greek world. Here it was, beyond the confines of actual Greek + territory, that Hellenic thought found its second home, its first home + being, as we have seen, in Asia Minor. Pythagoras, indeed, to whom we have + just been introduced, was born on the island of Samos, which lies near the + coast of Asia Minor, but he probably migrated at an early day to Crotona, + in Italy. There he lived, taught, and developed his philosophy until + rather late in life, when, having incurred the displeasure of his + fellow-citizens, he suffered the not unusual penalty of banishment. + </p> + <p> + Of the three other great Italic leaders of thought of the early period, + Xenophanes came rather late in life to Elea and founded the famous Eleatic + School, of which Parmenides became the most distinguished ornament. These + two were Ionians, and they lived in the sixth century before our era. + Empedocles, the Sicilian, was of Doric origin. He lived about the middle + of the fifth century B.C., at a time, therefore, when Athens had attained + a position of chief glory among the Greek states; but there is no evidence + that Empedocles ever visited that city, though it was rumored that he + returned to the Peloponnesus to die. The other great Italic philosophers + just named, living, as we have seen, in the previous century, can scarcely + have thought of Athens as a centre of Greek thought. Indeed, the very fact + that these men lived in Italy made that peninsula, rather than the + mother-land of Greece, the centre of Hellenic influence. But all these + men, it must constantly be borne in mind, were Greeks by birth and + language, fully recognized as such in their own time and by posterity. Yet + the fact that they lived in a land which was at no time a part of the + geographical territory of Greece must not be forgotten. They, or their + ancestors of recent generations, had been pioneers among those venturesome + colonists who reached out into distant portions of the world, and made + homes for themselves in much the same spirit in which colonists from + Europe began to populate America some two thousand years later. In + general, colonists from the different parts of Greece localized themselves + somewhat definitely in their new homes; yet there must naturally have been + a good deal of commingling among the various families of pioneers, and, to + a certain extent, a mingling also with the earlier inhabitants of the + country. This racial mingling, combined with the well-known vitalizing + influence of the pioneer life, led, we may suppose, to a more rapid and + more varied development than occurred among the home-staying Greeks. In + proof of this, witness the remarkable schools of philosophy which, as we + have seen, were thus developed at the confines of the Greek world, and + which were presently to invade and, as it were, take by storm the + mother-country itself. + </p> + <p> + As to the personality of these pioneer philosophers of the West, our + knowledge is for the most part more or less traditional. What has been + said of Thales may be repeated, in the main, regarding Pythagoras, + Parmenides, and Empedocles. That they were real persons is not at all in + question, but much that is merely traditional has come to be associated + with their names. Pythagoras was the senior, and doubtless his ideas may + have influenced the others more or less, though each is usually spoken of + as the founder of an independent school. Much confusion has all along + existed, however, as to the precise ideas which were to be ascribed to + each of the leaders. Numberless commentators, indeed, have endeavored to + pick out from among the traditions of antiquity, aided by such fragments, + of the writing of the philosophers as have come down to us, the particular + ideas that characterized each thinker, and to weave these ideas into + systems. But such efforts, notwithstanding the mental energy that has been + expended upon them, were, of necessity, futile, since, in the first place, + the ancient philosophers themselves did not specialize and systematize + their ideas according to modern notions, and, in the second place, the + records of their individual teachings have been too scantily preserved to + serve for the purpose of classification. It is freely admitted that fable + has woven an impenetrable mesh of contradictions about the personalities + of these ancient thinkers, and it would be folly to hope that this same + artificer had been less busy with their beliefs and theories. When one + reads that Pythagoras advocated an exclusively vegetable diet, yet that he + was the first to train athletes on meat diet; that he sacrificed only + inanimate things, yet that he offered up a hundred oxen in honor of his + great discovery regarding the sides of a triangle, and such like + inconsistencies in the same biography, one gains a realizing sense of the + extent to which diverse traditions enter into the story as it has come + down to us. And yet we must reflect that most men change their opinions in + the course of a long lifetime, and that the antagonistic reports may both + be true. + </p> + <p> + True or false, these fables have an abiding interest, since they prove the + unique and extraordinary character of the personality about which they are + woven. The alleged witticisms of a Whistler, in our own day, were + doubtless, for the most part, quite unknown to Whistler himself, yet they + never would have been ascribed to him were they not akin to witticisms + that he did originate—were they not, in short, typical expressions + of his personality. And so of the heroes of the past. "It is no ordinary + man," said George Henry Lewes, speaking of Pythagoras, "whom fable exalts + into the poetic region. Whenever you find romantic or miraculous deeds + attributed, be certain that the hero was great enough to maintain the + weight of the crown of this fabulous glory."(1) We may not doubt, then, + that Pythagoras, Parmenides, and Empedocles, with whose names fable was so + busy throughout antiquity, were men of extraordinary personality. We are + here chiefly concerned, however, neither with the personality of the man + nor yet with the precise doctrines which each one of them taught. A + knowledge of the latter would be interesting were it attainable, but in + the confused state of the reports that have come down to us we cannot hope + to be able to ascribe each idea with precision to its proper source. At + best we can merely outline, even here not too precisely, the scientific + doctrines which the Italic philosophers as a whole seem to have advocated. + </p> + <p> + First and foremost, there is the doctrine that the earth is a sphere. + Pythagoras is said to have been the first advocate of this theory; but, + unfortunately, it is reported also that Parmenides was its author. This + rivalship for the discovery of an important truth we shall see repeated + over and over in more recent times. Could we know the whole truth, it + would perhaps appear that the idea of the sphericity of the earth was + originated long before the time of the Greek philosophers. But it must be + admitted that there is no record of any sort to give tangible support to + such an assumption. So far as we can ascertain, no Egyptian or Babylonian + astronomer ever grasped the wonderful conception that the earth is round. + That the Italic Greeks should have conceived that idea was perhaps not so + much because they were astronomers as because they were practical + geographers and geometers. Pythagoras, as we have noted, was born at + Samos, and, therefore, made a relatively long sea voyage in passing to + Italy. Now, as every one knows, the most simple and tangible demonstration + of the convexity of the earth's surface is furnished by observation of an + approaching ship at sea. On a clear day a keen eye may discern the mast + and sails rising gradually above the horizon, to be followed in due course + by the hull. Similarly, on approaching the shore, high objects become + visible before those that lie nearer the water. It is at least a plausible + supposition that Pythagoras may have made such observations as these + during the voyage in question, and that therein may lie the germ of that + wonderful conception of the world as a sphere. + </p> + <p> + To what extent further proof, based on the fact that the earth's shadow + when the moon is eclipsed is always convex, may have been known to + Pythagoras we cannot say. There is no proof that any of the Italic + philosophers made extensive records of astronomical observations as did + the Egyptians and Babylonians; but we must constantly recall that the + writings of classical antiquity have been almost altogether destroyed. The + absence of astronomical records is, therefore, no proof that such records + never existed. Pythagoras, it should be said, is reported to have + travelled in Egypt, and he must there have gained an inkling of + astronomical methods. Indeed, he speaks of himself specifically, in a + letter quoted by Diogenes, as one who is accustomed to study astronomy. + Yet a later sentence of the letter, which asserts that the philosopher is + not always occupied about speculations of his own fancy, suggesting, as it + does, the dreamer rather than the observer, gives us probably a truer + glimpse into the philosopher's mind. There is, indeed, reason to suppose + that the doctrine of the sphericity of the earth appealed to Pythagoras + chiefly because it accorded with his conception that the sphere is the + most perfect solid, just as the circle is the most perfect plane surface. + Be that as it may, the fact remains that we have here, as far as we can + trace its origin, the first expression of the scientific theory that the + earth is round. Had the Italic philosophers accomplished nothing more than + this, their accomplishment would none the less mark an epoch in the + progress of thought. + </p> + <p> + That Pythagoras was an observer of the heavens is further evidenced by the + statement made by Diogenes, on the authority of Parmenides, that + Pythagoras was the first person who discovered or asserted the identity of + Hesperus and Lucifer—that is to say, of the morning and the evening + star. This was really a remarkable discovery, and one that was no doubt + instrumental later on in determining that theory of the mechanics of the + heavens which we shall see elaborated presently. To have made such a + discovery argues again for the practicality of the mind of Pythagoras. + His, indeed, would seem to have been a mind in which practical + common-sense was strangely blended with the capacity for wide and + imaginative generalization. As further evidence of his practicality, it is + asserted that he was the first person who introduced measures and weights + among the Greeks, this assertion being made on the authority of + Aristoxenus. It will be observed that he is said to have introduced, not + to have invented, weights and measures, a statement which suggests a + knowledge on the part of the Greeks that weights and measures were + previously employed in Egypt and Babylonia. + </p> + <p> + The mind that could conceive the world as a sphere and that interested + itself in weights and measures was, obviously, a mind of the visualizing + type. It is characteristic of this type of mind to be interested in the + tangibilities of geometry, hence it is not surprising to be told that + Pythagoras "carried that science to perfection." The most famous discovery + of Pythagoras in this field was that the square of the hypotenuse of a + right-angled triangle is equal to the squares of the other sides of the + triangle. We have already noted the fable that his enthusiasm over this + discovery led him to sacrifice a hecatomb. Doubtless the story is + apocryphal, but doubtless, also, it expresses the truth as to the fervid + joy with which the philosopher must have contemplated the results of his + creative imagination. + </p> + <p> + No line alleged to have been written by Pythagoras has come down to us. We + are told that he refrained from publishing his doctrines, except by word + of mouth. "The Lucanians and the Peucetians, and the Messapians and the + Romans," we are assured, "flocked around him, coming with eagerness to + hear his discourses; no fewer than six hundred came to him every night; + and if any one of them had ever been permitted to see the master, they + wrote of it to their friends as if they had gained some great advantage." + Nevertheless, we are assured that until the time of Philolaus no doctrines + of Pythagoras were ever published, to which statement it is added that + "when the three celebrated books were published, Plato wrote to have them + purchased for him for a hundred minas."(2) But if such books existed, they + are lost to the modern world, and we are obliged to accept the assertions + of relatively late writers as to the theories of the great Crotonian. + </p> + <p> + Perhaps we cannot do better than quote at length from an important summary + of the remaining doctrines of Pythagoras, which Diogenes himself quoted + from the work of a predecessor.(3) Despite its somewhat inchoate + character, this summary is a most remarkable one, as a brief analysis of + its contents will show. It should be explained that Alexander (whose work + is now lost) is said to have found these dogmas set down in the + commentaries of Pythagoras. If this assertion be accepted, we are brought + one step nearer the philosopher himself. The summary is as follows: + </p> + <p> + "That the monad was the beginning of everything. From the monad proceeds + an indefinite duad, which is subordinate to the monad as to its cause. + That from the monad and the indefinite duad proceed numbers. And from + numbers signs. And from these last, lines of which plane figures consist. + And from plane figures are derived solid bodies. And from solid bodies + sensible bodies, of which last there are four elements—fire, water, + earth, and air. And that the world, which is indued with life and + intellect, and which is of a spherical figure, having the earth, which is + also spherical, and inhabited all over in its centre,(4) results from a + combination of these elements, and derives its motion from them; and also + that there are antipodes, and that what is below, as respects us, is above + in respect of them. + </p> + <p> + "He also taught that light and darkness, and cold and heat, and dryness + and moisture, were equally divided in the world; and that while heat was + predominant it was summer; while cold had the mastery, it was winter; when + dryness prevailed, it was spring; and when moisture preponderated, winter. + And while all these qualities were on a level, then was the loveliest + season of the year; of which the flourishing spring was the wholesome + period, and the season of autumn the most pernicious one. Of the day, he + said that the flourishing period was the morning, and the fading one the + evening; on which account that also was the least healthy time. + </p> + <p> + "Another of his theories was that the air around the earth was immovable + and pregnant with disease, and that everything in it was mortal; but that + the upper air was in perpetual motion, and pure and salubrious, and that + everything in that was immortal, and on that account divine. And that the + sun and the moon and the stars were all gods; for in them the warm + principle predominates which is the cause of life. And that the moon + derives its light from the sun. And that there is a relationship between + men and the gods, because men partake of the divine principle; on which + account, also, God exercises his providence for our advantage. Also, that + Fate is the cause of the arrangement of the world both generally and + particularly. Moreover, that a ray from the sun penetrated both the cold + aether and the dense aether; and they call the air the cold aether, and + the sea and moisture they call the dense aether. And this ray descends + into the depths, and in this way vivifies everything. And everything which + partakes of the principle of heat lives, on which account, also, plants + are animated beings; but that all living things have not necessarily + souls. And that the soul is a something tom off from the aether, both warm + and cold, from its partaking of the cold aether. And that the soul is + something different from life. Also, that it is immortal, because that + from which it has been detached is immortal. + </p> + <p> + "Also, that animals are born from one another by seeds, and that it is + impossible for there to be any spontaneous production by the earth. And + that seed is a drop from the brain which contains in itself a warm vapor; + and that when this is applied to the womb it transmits virtue and moisture + and blood from the brain, from which flesh and sinews and bones and hair + and the whole body are produced. And from the vapor is produced the soul, + and also sensation. And that the infant first becomes a solid body at the + end of forty days; but, according to the principles of harmony, it is not + perfect till seven, or perhaps nine, or at most ten months, and then it is + brought forth. And that it contains in itself all the principles of life, + which are all connected together, and by their union and combination form + a harmonious whole, each of them developing itself at the appointed time. + </p> + <p> + "The senses in general, and especially the sight, are a vapor of excessive + warmth, and on this account a man is said to see through air and through + water. For the hot principle is opposed by the cold one; since, if the + vapor in the eyes were cold, it would have the same temperature as the + air, and so would be dissipated. As it is, in some passages he calls the + eyes the gates of the sun; and he speaks in a similar manner of hearing + and of the other senses. + </p> + <p> + "He also says that the soul of man is divided into three parts: into + intuition and reason and mind, and that the first and last divisions are + found also in other animals, but that the middle one, reason, is only + found in man. And that the chief abode of the soul is in those parts of + the body which are between the heart and the brain. And that that portion + of it which is in the heart is the mind; but that deliberation and reason + reside in the brain. + </p> + <p> + "Moreover, that the senses are drops from them; and that the reasoning + sense is immortal, but the others are mortal. And that the soul is + nourished by the blood; and that reasons are the winds of the soul. That + it is invisible, and so are its reasons, since the aether itself is + invisible. That the links of the soul are the veins and the arteries and + the nerves. But that when it is vigorous, and is by itself in a quiescent + state, then its links are words and actions. That when it is cast forth + upon the earth it wanders about, resembling the body. Moreover, that + Mercury is the steward of the souls, and that on this account he has the + name of Conductor, and Commercial, and Infernal, since it is he who + conducts the souls from their bodies, and from earth and sea; and that he + conducts the pure souls to the highest region, and that he does not allow + the impure ones to approach them, nor to come near one another, but + commits them to be bound in indissoluble fetters by the Furies. The + Pythagoreans also assert that the whole air is full of souls, and that + these are those which are accounted daemons and heroes. Also, that it is + by them that dreams are sent among men, and also the tokens of disease and + health; these last, too, being sent not only to men, but to sheep also, + and other cattle. Also that it is they who are concerned with + purifications and expiations and all kinds of divination and oracular + predictions, and things of that kind."(5) + </p> + <p> + A brief consideration of this summary of the doctrines of Pythagoras will + show that it at least outlines a most extraordinary variety of scientific + ideas. (1) There is suggested a theory of monads and the conception of the + development from simple to more complex bodies, passing through the stages + of lines, plain figures, and solids to sensible bodies. (2) The doctrine + of the four elements—fire, water, earth, and air—as the basis + of all organisms is put forward. (3) The idea, not merely of the + sphericity of the earth, but an explicit conception of the antipodes, is + expressed. (4) A conception of the sanitary influence of the air is + clearly expressed. (5) An idea of the problems of generation and heredity + is shown, together with a distinct disavowal of the doctrine of + spontaneous generation—a doctrine which, it may be added, remained + in vogue, nevertheless, for some twenty-four hundred years after the time + of Pythagoras. (6) A remarkable analysis of mind is made, and a + distinction between animal minds and the human mind is based on this + analysis. The physiological doctrine that the heart is the organ of one + department of mind is offset by the clear statement that the remaining + factors of mind reside in the brain. This early recognition of brain as + the organ of mind must not be forgotten in our later studies. It should be + recalled, however, that a Crotonian physician, Alemaean, a younger + contemporary of Pythagoras, is also credited with the same theory. (7) A + knowledge of anatomy is at least vaguely foreshadowed in the assertion + that veins, arteries, and nerves are the links of the soul. In this + connection it should be recalled that Pythagoras was a practical + physician. + </p> + <p> + As against these scientific doctrines, however, some of them being at + least remarkable guesses at the truth, attention must be called to the + concluding paragraph of our quotation, in which the old familiar + daemonology is outlined, quite after the Oriental fashion. We shall have + occasion to say more as to this phase of the subject later on. Meantime, + before leaving Pythagoras, let us note that his practical studies of + humanity led him to assert the doctrine that "the property of friends is + common, and that friendship is equality." His disciples, we are told, used + to put all their possessions together in one store and use them in common. + Here, then, seemingly, is the doctrine of communism put to the test of + experiment at this early day. If it seem that reference to this carries us + beyond the bounds of science, it may be replied that questions such as + this will not lie beyond the bounds of the science of the near future. + </p> + <p> + XENOPHANES AND PARMENIDES + </p> + <p> + There is a whimsical tale about Pythagoras, according to which the + philosopher was wont to declare that in an earlier state he had visited + Hades, and had there seen Homer and Hesiod tortured because of the absurd + things they had said about the gods. Apocrypbal or otherwise, the tale + suggests that Pythagoras was an agnostic as regards the current Greek + religion of his time. The same thing is perhaps true of most of the great + thinkers of this earliest period. But one among them was remembered in + later times as having had a peculiar aversion to the anthropomorphic + conceptions of his fellows. This was Xenophanes, who was born at Colophon + probably about the year 580 B.C., and who, after a life of wandering, + settled finally in Italy and became the founder of the so-called Eleatic + School. + </p> + <p> + A few fragments of the philosophical poem in which Xenophanes expressed + his views have come down to us, and these fragments include a tolerably + definite avowal of his faith. "God is one supreme among gods and men, and + not like mortals in body or in mind," says Xenophanes. Again he asserts + that "mortals suppose that the gods are born (as they themselves are), + that they wear man's clothing and have human voice and body; but," he + continues, "if cattle or lions had hands so as to paint with their hands + and produce works of art as men do, they would paint their gods and give + them bodies in form like their own—horses like horses, cattle like + cattle." Elsewhere he says, with great acumen: "There has not been a man, + nor will there be, who knows distinctly what I say about the gods or in + regard to all things. For even if one chance for the most part to say what + is true, still he would not know; but every one thinks that he knows."(6) + </p> + <p> + In the same spirit Xenophanes speaks of the battles of Titans, of giants, + and of centaurs as "fictions of former ages." All this tells of the + questioning spirit which distinguishes the scientific investigator. + Precisely whither this spirit led him we do not know, but the writers of a + later time have preserved a tradition regarding a belief of Xenophanes + that perhaps entitles him to be considered the father of geology. Thus + Hippolytus records that Xenophanes studied the fossils to be found in + quarries, and drew from their observation remarkable conclusions. His + words are as follows: "Xenophanes believes that once the earth was mingled + with the sea, but in the course of time it became freed from moisture; and + his proofs are such as these: that shells are found in the midst of the + land and among the mountains, that in the quarries of Syracuse the + imprints of a fish and of seals had been found, and in Paros the imprint + of an anchovy at some depth in the stone, and in Melite shallow + impressions of all sorts of sea products. He says that these imprints were + made when everything long ago was covered with mud, and then the imprint + dried in the mud. Further, he says that all men will be destroyed when the + earth sinks into the sea and becomes mud, and that the race will begin + anew from the beginning; and this transformation takes place for all + worlds."(7) Here, then, we see this earliest of paleontologists studying + the fossil-bearing strata of the earth, and drawing from his observations + a marvellously scientific induction. Almost two thousand years later + another famous citizen of Italy, Leonardo da Vinci, was independently to + think out similar conclusions from like observations. But not until the + nineteenth century of our era, some twenty-four hundred years after the + time of Xenophanes, was the old Greek's doctrine to be accepted by the + scientific world. The ideas of Xenophanes were known to his contemporaries + and, as we see, quoted for a few centuries by his successors, then they + were ignored or quite forgotten; and if any philosopher of an ensuing age + before the time of Leonardo championed a like rational explanation of the + fossils, we have no record of the fact. The geological doctrine of + Xenophanes, then, must be listed among those remarkable Greek + anticipations of nineteenth-century science which suffered almost total + eclipse in the intervening centuries. + </p> + <p> + Among the pupils of Xenophanes was Parmenides, the thinker who was + destined to carry on the work of his master along the same scientific + lines, though at the same time mingling his scientific conceptions with + the mysticism of the poet. We have already had occasion to mention that + Parmenides championed the idea that the earth is round; noting also that + doubts exist as to whether he or Pythagoras originated this doctrine. No + explicit answer to this question can possibly be hoped for. It seems + clear, however, that for a long time the Italic School, to which both + these philosophers belonged, had a monopoly of the belief in question. + Parmenides, like Pythagoras, is credited with having believed in the + motion of the earth, though the evidence furnished by the writings of the + philosopher himself is not as demonstrative as one could wish. + Unfortunately, the copyists of a later age were more concerned with + metaphysical speculations than with more tangible things. But as far as + the fragmentary references to the ideas of Parmenides may be accepted, + they do not support the idea of the earth's motion. Indeed, Parmenides is + made to say explicitly, in preserved fragments, that "the world is + immovable, limited, and spheroidal in form."(8) + </p> + <p> + Nevertheless, some modern interpreters have found an opposite meaning in + Parmenides. Thus Ritter interprets him as supposing "that the earth is in + the centre spherical, and maintained in rotary motion by its + equiponderance; around it lie certain rings, the highest composed of the + rare element fire, the next lower a compound of light and darkness, and + lowest of all one wholly of night, which probably indicated to his mind + the surface of the earth, the centre of which again he probably considered + to be fire."(9) But this, like too many interpretations of ancient + thought, appears to read into the fragments ideas which the words + themselves do not warrant. There seems no reason to doubt, however, that + Parmenides actually held the doctrine of the earth's sphericity. Another + glimpse of his astronomical doctrines is furnished us by a fragment which + tells us that he conceived the morning and the evening stars to be the + same, a doctrine which, as we have seen, was ascribed also to Pythagoras. + Indeed, we may repeat that it is quite impossible to distinguish between + the astronomical doctrines of these two philosophers. + </p> +<pre xml:space="preserve"> +The poem of Parmenides in which the cosmogonic speculations occur +treats also of the origin of man. The author seems to have had a clear +conception that intelligence depends on bodily organism, and that the +more elaborately developed the organism the higher the intelligence. +But in the interpretation of this thought we are hampered by the +characteristic vagueness of expression, which may best be evidenced by +putting before the reader two English translations of the same stanza. +Here is Ritter's rendering, as made into English by his translator, +Morrison: + + "For exactly as each has the state of his limbs many-jointed, +So invariably stands it with men in their mind and their reason; For the +system of limbs is that which thinketh in mankind Alike in all and in +each: for thought is the fulness."(10) +</pre> + <p> + The same stanza is given thus by George Henry Lewes: + </p> +<pre xml:space="preserve"> + "Such as to each man is the nature of his many-jointed limbs, +Such also is the intelligence of each man; for it is The nature of limbs +(organization) which thinketh in men, Both in one and in all; for the +highest degree of organization gives the highest degree of thought."(11) +</pre> + <p> + Here it will be observed that there is virtual agreement between the + translators except as to the last clause, but that clause is most + essential. The Greek phrase is (gr to gar pleon esti nohma). Ritter, it + will be observed, renders this, "for thought is the fulness." Lewes + paraphrases it, "for the highest degree of organization gives the highest + degree of thought." The difference is intentional, since Lewes himself + criticises the translation of Ritter. Ritter's translation is certainly + the more literal, but the fact that such diversity is possible suggests + one of the chief elements of uncertainty that hamper our interpretation of + the thought of antiquity. Unfortunately, the mind of the commentator has + usually been directed towards such subtleties, rather than towards the + expression of precise knowledge. Hence it is that the philosophers of + Greece are usually thought of as mere dreamers, and that their true status + as scientific discoverers is so often overlooked. With these + intangibilities we have no present concern beyond this bare mention; for + us it suffices to gain as clear an idea as we may of the really scientific + conceptions of these thinkers, leaving the subtleties of their deductive + reasoning for the most part untouched. + </p> + <p> + EMPEDOCLES + </p> + <p> + The latest of the important pre-Socratic philosophers of the Italic school + was Empedocles, who was born about 494 B.C. and lived to the age of sixty. + These dates make Empedocles strictly contemporary with Anaxagoras, a fact + which we shall do well to bear in mind when we come to consider the + latter's philosophy in the succeeding chapter. Like Pythagoras, Empedocles + is an imposing figure. Indeed, there is much of similarity between the + personalities, as between the doctrines, of the two men. Empedocles, like + Pythagoras, was a physician; like him also he was the founder of a cult. + As statesman, prophet, physicist, physician, reformer, and poet he showed + a versatility that, coupled with profundity, marks the highest genius. In + point of versatility we shall perhaps hardly find his equal at a later day—unless, + indeed, an exception be made of Eratosthenes. The myths that have grown + about the name of Empedocles show that he was a remarkable personality. He + is said to have been an awe-inspiring figure, clothing himself in Oriental + splendor and moving among mankind as a superior being. Tradition has it + that he threw himself into the crater of a volcano that his otherwise + unexplained disappearance might lead his disciples to believe that he had + been miraculously translated; but tradition goes on to say that one of the + brazen slippers of the philosopher was thrown up by the volcano, thus + revealing his subterfuge. Another tradition of far more credible aspect + asserts that Empedocles retreated from Italy, returning to the home of his + fathers in Peloponnesus to die there obscurely. It seems odd that the + facts regarding the death of so great a man, at so comparatively late a + period, should be obscure; but this, perhaps, is in keeping with the + personality of the man himself. His disciples would hesitate to ascribe a + merely natural death to so inspired a prophet. + </p> + <p> + Empedocles appears to have been at once an observer and a dreamer. He is + credited with noting that the pressure of air will sustain the weight of + water in an inverted tube; with divining, without the possibility of + proof, that light has actual motion in space; and with asserting that + centrifugal motion must keep the heavens from falling. He is credited with + a great sanitary feat in the draining of a marsh, and his knowledge of + medicine was held to be supernatural. Fortunately, some fragments of the + writings of Empedocles have come down to us, enabling us to judge at first + hand as to part of his doctrines; while still more is known through the + references made to him by Plato, Aristotle, and other commentators. + Empedocles was a poet whose verses stood the test of criticism. In this + regard he is in a like position with Parmenides; but in neither case are + the preserved fragments sufficient to enable us fully to estimate their + author's scientific attainments. Philosophical writings are obscure enough + at the best, and they perforce become doubly so when expressed in verse. + Yet there are certain passages of Empedocles that are unequivocal and full + of interest. Perhaps the most important conception which the works of + Empedocles reveal to us is the denial of anthropomorphism as applied to + deity. We have seen how early the anthropomorphic conception was developed + and how closely it was all along clung to; to shake the mind free from it + then was a remarkable feat, in accomplishing which Empedocles took a long + step in the direction of rationalism. His conception is paralleled by that + of another physician, Alcmaeon, of Proton, who contended that man's ideas + of the gods amounted to mere suppositions at the very most. A + rationalistic or sceptical tendency has been the accompaniment of medical + training in all ages. + </p> + <p> + The words in which Empedocles expresses his conception of deity have been + preserved and are well worth quoting: "It is not impossible," he says, "to + draw near (to god) even with the eyes or to take hold of him with our + hands, which in truth is the best highway of persuasion in the mind of + man; for he has no human head fitted to a body, nor do two shoots branch + out from the trunk, nor has he feet, nor swift legs, nor hairy parts, but + he is sacred and ineffable mind alone, darting through the whole world + with swift thoughts."(8) + </p> + <p> + How far Empedocles carried his denial of anthropomorphism is illustrated + by a reference of Aristotle, who asserts "that Empedocles regards god as + most lacking in the power of perception; for he alone does not know one of + the elements, Strife (hence), of perishable things." It is difficult to + avoid the feeling that Empedocles here approaches the modern philosophical + conception that God, however postulated as immutable, must also be + postulated as unconscious, since intelligence, as we know it, is dependent + upon the transmutations of matter. But to urge this thought would be to + yield to that philosophizing tendency which has been the bane of + interpretation as applied to the ancient thinkers. + </p> + <p> + Considering for a moment the more tangible accomplishments of Empedocles, + we find it alleged that one of his "miracles" consisted of the + preservation of a dead body without putrefaction for some weeks after + death. We may assume from this that he had gained in some way a knowledge + of embalming. As he was notoriously fond of experiment, and as the body in + question (assuming for the moment the authenticity of the legend) must + have been preserved without disfigurement, it is conceivable even that he + had hit upon the idea of injecting the arteries. This, of course, is pure + conjecture; yet it finds a certain warrant, both in the fact that the + words of Pythagoras lead us to believe that the arteries were known and + studied, and in the fact that Empedocles' own words reveal him also as a + student of the vascular system. Thus Plutarch cites Empedocles as + believing "that the ruling part is not in the head or in the breast, but + in the blood; wherefore in whatever part of the body the more of this is + spread in that part men excel."(13) And Empedocles' own words, as + preserved by Stobaeus, assert "(the heart) lies in seas of blood which + dart in opposite directions, and there most of all intelligence centres + for men; for blood about the heart is intelligence in the case of man." + All this implies a really remarkable appreciation of the dependence of + vital activities upon the blood. + </p> + <p> + This correct physiological conception, however, was by no means the most + remarkable of the ideas to which Empedoeles was led by his anatomical + studies. His greatest accomplishment was to have conceived and clearly + expressed an idea which the modern evolutionist connotes when he speaks of + homologous parts—an idea which found a famous modern expositor in + Goethe, as we shall see when we come to deal with eighteenth-century + science. Empedocles expresses the idea in these words: "Hair, and leaves, + and thick feathers of birds, are the same thing in origin, and reptile + scales too on strong limbs. But on hedgehogs sharp-pointed hair bristles + on their backs."(14) That the idea of transmutation of parts, as well as + of mere homology, was in mind is evidenced by a very remarkable sentence + in which Aristotle asserts, "Empedocles says that fingernails rise from + sinew from hardening." Nor is this quite all, for surely we find the germ + of the Lamarckian conception of evolution through the transmission of + acquired characters in the assertion that "many characteristics appear in + animals because it happened to be thus in their birth, as that they have + such a spine because they happen to be descended from one that bent itself + backward."(15) Aristotle, in quoting this remark, asserts, with the + dogmatism which characterizes the philosophical commentators of every age, + that "Empedocles is wrong," in making this assertion; but Lamarck, who + lived twenty-three hundred years after Empedocles, is famous in the + history of the doctrine of evolution for elaborating this very idea. + </p> + <p> + It is fair to add, however, that the dreamings of Empedocles regarding the + origin of living organisms led him to some conceptions that were much less + luminous. On occasion, Empedocles the poet got the better of Empedocles + the scientist, and we are presented with a conception of creation as + grotesque as that which delighted the readers of Paradise Lost at a later + day. Empedocles assures us that "many heads grow up without necks, and + arms were wandering about, necks bereft of shoulders, and eyes roamed + about alone with no foreheads."(16) This chaotic condition, so the poet + dreamed, led to the union of many incongruous parts, producing "creatures + with double faces, offspring of oxen with human faces, and children of men + with oxen heads." But out of this chaos came, finally, we are led to + infer, a harmonious aggregation of parts, producing ultimately the + perfected organisms that we see. Unfortunately the preserved portions of + the writings of Empedocles do not enlighten us as to the precise way in + which final evolution was supposed to be effected; although the idea of + endless experimentation until natural selection resulted in survival of + the fittest seems not far afield from certain of the poetical assertions. + Thus: "As divinity was mingled yet more with divinity, these things (the + various members) kept coming together in whatever way each might chance." + Again: "At one time all the limbs which form the body united into one by + love grew vigorously in the prime of life; but yet at another time, + separated by evil Strife, they wander each in different directions along + the breakers of the sea of life. Just so is it with plants, and with + fishes dwelling in watery halls, and beasts whose lair is in the + mountains, and birds borne on wings."(17) + </p> + <p> + All this is poetry rather than science, yet such imaginings could come + only to one who was groping towards what we moderns should term an + evolutionary conception of the origins of organic life; and however + grotesque some of these expressions may appear, it must be admitted that + the morphological ideas of Empedocles, as above quoted, give the Sicilian + philosopher a secure place among the anticipators of the modern + evolutionist. + </p> + <p> + <a name="link2H_4_0009" id="link2H_4_0009"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + </h2> + <p> + We have travelled rather far in our study of Greek science, and yet we + have not until now come to Greece itself. And even now, the men whose + names we are to consider were, for the most part, born in out-lying + portions of the empire; they differed from the others we have considered + only in the fact that they were drawn presently to the capital. The change + is due to a most interesting sequence of historical events. In the day + when Thales and his immediate successors taught in Miletus, when the great + men of the Italic school were in their prime, there was no single + undisputed Centre of Greek influence. The Greeks were a disorganized + company of petty nations, welded together chiefly by unity of speech; but + now, early in the fifth century B.C., occurred that famous attack upon the + Western world by the Persians under Darius and his son and successor + Xerxes. A few months of battling determined the fate of the Western world. + The Orientals were hurled back; the glorious memories of Marathon, + Salamis, and Plataea stimulated the patriotism and enthusiasm of all + children of the Greek race. The Greeks, for the first time, occupied the + centre of the historical stage; for the brief interval of about half a + century the different Grecian principalities lived together in relative + harmony. One city was recognized as the metropolis of the loosely bound + empire; one city became the home of culture and the Mecca towards which + all eyes turned; that city, of course, was Athens. For a brief time all + roads led to Athens, as, at a later date, they all led to Rome. The + waterways which alone bound the widely scattered parts of Hellas into a + united whole led out from Athens and back to Athens, as the spokes of a + wheel to its hub. Athens was the commercial centre, and, largely for that + reason, it became the centre of culture and intellectual influence also. + The wise men from the colonies visited the metropolis, and the wise + Athenians went out to the colonies. Whoever aspired to become a leader in + politics, in art, in literature, or in philosophy, made his way to the + capital, and so, with almost bewildering suddenness, there blossomed the + civilization of the age of Pericles; the civilization which produced + aeschylus, Sophocles, Euripides, Herodotus, and Thucydides; the + civilization which made possible the building of the Parthenon. + </p> + <p> + ANAXAGORAS + </p> + <p> + Sometime during the early part of this golden age there came to Athens a + middle-aged man from Clazomenae, who, from our present stand-point, was a + more interesting personality than perhaps any other in the great galaxy of + remarkable men assembled there. The name of this new-comer was Anaxagoras. + It was said in after-time, we know not with what degree of truth, that he + had been a pupil of Anaximenes. If so, he was a pupil who departed far + from the teachings of his master. What we know for certain is that + Anaxagoras was a truly original thinker, and that he became a close friend—in + a sense the teacher—of Pericles and of Euripides. Just how long he + remained at Athens is not certain; but the time came when he had made + himself in some way objectionable to the Athenian populace through his + teachings. Filled with the spirit of the investigator, he could not accept + the current conceptions as to the gods. He was a sceptic, an innovator. + Such men are never welcome; they are the chief factors in the progress of + thought, but they must look always to posterity for recognition of their + worth; from their contemporaries they receive, not thanks, but + persecution. Sometimes this persecution takes one form, sometimes another; + to the credit of the Greeks be it said, that with them it usually led to + nothing more severe than banishment. In the case of Anaxagoras, it is + alleged that the sentence pronounced was death; but that, thanks to the + influence of Pericles, this sentence was commuted to banishment. In any + event, the aged philosopher was sent away from the city of his adoption. + He retired to Lampsacus. "It is not I that have lost the Athenians," he + said; "it is the Athenians that have lost me." + </p> + <p> + The exact position which Anaxagoras had among his contemporaries, and his + exact place in the development of philosophy, have always been somewhat in + dispute. It is not known, of a certainty, that he even held an open school + at Athens. Ritter thinks it doubtful that he did. It was his fate to be + misunderstood, or underestimated, by Aristotle; that in itself would have + sufficed greatly to dim his fame—might, indeed, have led to his + almost entire neglect had he not been a truly remarkable thinker. With + most of the questions that have exercised the commentators we have but + scant concern. Following Aristotle, most historians of philosophy have + been metaphysicians; they have concerned themselves far less with what the + ancient thinkers really knew than with what they thought. A chance using + of a verbal quibble, an esoteric phrase, the expression of a vague + mysticism—these would suffice to call forth reams of exposition. It + has been the favorite pastime of historians to weave their own + anachronistic theories upon the scanty woof of the half-remembered + thoughts of the ancient philosophers. To make such cloth of the + imagination as this is an alluring pastime, but one that must not divert + us here. Our point of view reverses that of the philosophers. We are + chiefly concerned, not with some vague saying of Anaxagoras, but with what + he really knew regarding the phenomena of nature; with what he observed, + and with the comprehensible deductions that he derived from his + observations. In attempting to answer these inquiries, we are obliged, in + part, to take our evidence at second-hand; but, fortunately, some + fragments of writings of Anaxagoras have come down to us. We are told that + he wrote only a single book. It was said even (by Diogenes) that he was + the first man that ever wrote a work in prose. The latter statement would + not bear too close an examination, yet it is true that no extensive prose + compositions of an earlier day than this have been preserved, though + numerous others are known by their fragments. Herodotus, "the father of + prose," was a slightly younger contemporary of the Clazomenaean + philosopher; not unlikely the two men may have met at Athens. + </p> + <p> + Notwithstanding the loss of the greater part of the writings of + Anaxagoras, however, a tolerably precise account of his scientific + doctrines is accessible. Diogenes Laertius expresses some of them in very + clear and precise terms. We have already pointed out the uncertainty that + attaches to such evidence as this, but it is as valid for Anaxagoras as + for another. If we reject such evidence, we shall often have almost + nothing left; in accepting it we may at least feel certain that we are + viewing the thinker as his contemporaries and immediate successors viewed + him. Following Diogenes, then, we shall find some remarkable scientific + opinions ascribed to Anaxagoras. "He asserted," we are told, "that the sun + was a mass of burning iron, greater than Peloponnesus, and that the moon + contained houses and also hills and ravines." In corroboration of this, + Plato represents him as having conjectured the right explanation of the + moon's light, and of the solar and lunar eclipses. He had other + astronomical theories that were more fanciful; thus "he said that the + stars originally moved about in irregular confusion, so that at first the + pole-star, which is continually visible, always appeared in the zenith, + but that afterwards it acquired a certain declination, and that the Milky + Way was a reflection of the light of the sun when the stars did not + appear. The comets he considered to be a concourse of planets emitting + rays, and the shooting-stars he thought were sparks, as it were, leaping + from the firmament." + </p> + <p> + Much of this is far enough from the truth, as we now know it, yet all of + it shows an earnest endeavor to explain the observed phenomena of the + heavens on rational principles. To have predicated the sun as a great + molten mass of iron was indeed a wonderful anticipation of the results of + the modern spectroscope. Nor can it be said that this hypothesis of + Anaxagoras was a purely visionary guess. It was in all probability a + scientific deduction from the observed character of meteoric stones. + Reference has already been made to the alleged prediction of the fall of + the famous meteor at aegespotomi by Anaxagoras. The assertion that he + actually predicted this fall in any proper sense of the word would be + obviously absurd. Yet the fact that his name is associated with it + suggests that he had studied similar meteorites, or else that he studied + this particular one, since it is not quite clear whether it was before or + after this fall that he made the famous assertion that space is full of + falling stones. We should stretch the probabilities were we to assert that + Anaxagoras knew that shooting-stars and meteors were the same, yet there + is an interesting suggestiveness in his likening the shooting-stars to + sparks leaping from the firmament, taken in connection with his + observation on meteorites. Be this as it may, the fact that something + which falls from heaven as a blazing light turns out to be an iron-like + mass may very well have suggested to the most rational of thinkers that + the great blazing light called the sun has the same composition. This idea + grasped, it was a not unnatural extension to conceive the other heavenly + bodies as having the same composition. + </p> + <p> + This led to a truly startling thought. Since the heavenly bodies are of + the same composition as the earth, and since they are observed to be + whirling about the earth in space, may we not suppose that they were once + a part of the earth itself, and that they have been thrown off by the + force of a whirling motion? Such was the conclusion which Anaxagoras + reached; such his explanation of the origin of the heavenly bodies. It was + a marvellous guess. Deduct from it all that recent science has shown to be + untrue; bear in mind that the stars are suns, compared with which the + earth is a mere speck of dust; recall that the sun is parent, not + daughter, of the earth, and despite all these deductions, the cosmogonic + guess of Anaxagoras remains, as it seems to us, one of the most marvellous + feats of human intelligence. It was the first explanation of the cosmic + bodies that could be called, in any sense, an anticipation of what the + science of our own day accepts as a true explanation of cosmic origins. + Moreover, let us urge again that this was no mere accidental flight of the + imagination; it was a scientific induction based on the only data + available; perhaps it is not too much to say that it was the only + scientific induction which these data would fairly sustain. Of course it + is not for a moment to be inferred that Anaxagoras understood, in the + modern sense, the character of that whirling force which we call + centrifugal. About two thousand years were yet to elapse before that force + was explained as elementary inertia; and even that explanation, let us not + forget, merely sufficed to push back the barriers of mystery by one other + stage; for even in our day inertia is a statement of fact rather than an + explanation. + </p> + <p> + But however little Anaxagoras could explain the centrifugal force on + mechanical principles, the practical powers of that force were + sufficiently open to his observation. The mere experiment of throwing a + stone from a sling would, to an observing mind, be full of suggestiveness. + It would be obvious that by whirling the sling about, the stone which it + held would be sustained in its circling path about the hand in seeming + defiance of the earth's pull, and after the stone had left the sling, it + could fly away from the earth to a distance which the most casual + observation would prove to be proportionate to the speed of its flight. + Extremely rapid motion, then, might project bodies from the earth's + surface off into space; a sufficiently rapid whirl would keep them there. + Anaxagoras conceived that this was precisely what had occurred. His + imagination even carried him a step farther—to a conception of a + slackening of speed, through which the heavenly bodies would lose their + centrifugal force, and, responding to the perpetual pull of gravitation, + would fall back to the earth, just as the great stone at aegespotomi had + been observed to do. + </p> + <p> + Here we would seem to have a clear conception of the idea of universal + gravitation, and Anaxagoras stands before us as the anticipator of Newton. + Were it not for one scientific maxim, we might exalt the old Greek above + the greatest of modern natural philosophers; but that maxim bids us pause. + It is phrased thus, "He discovers who proves." Anaxagoras could not prove; + his argument was at best suggestive, not demonstrative. He did not even + know the laws which govern falling bodies; much less could he apply such + laws, even had he known them, to sidereal bodies at whose size and + distance he could only guess in the vaguest terms. Still his cosmogonic + speculation remains as perhaps the most remarkable one of antiquity. How + widely his speculation found currency among his immediate successors is + instanced in a passage from Plato, where Socrates is represented as + scornfully answering a calumniator in these terms: "He asserts that I say + the sun is a stone and the moon an earth. Do you think of accusing + Anaxagoras, Miletas, and have you so low an opinion of these men, and + think them so unskilled in laws, as not to know that the books of + Anaxagoras the Clazomenaean are full of these doctrines. And forsooth the + young men are learning these matters from me which sometimes they can buy + from the orchestra for a drachma, at the most, and laugh at Socrates if he + pretends they are his-particularly seeing they are so strange." + </p> + <p> + The element of error contained in these cosmogonic speculations of + Anaxagoras has led critics to do them something less than justice. But + there is one other astronomical speculation for which the Clazomenaean + philosopher has received full credit. It is generally admitted that it was + he who first found out the explanation of the phases of the moon; a + knowledge that that body shines only by reflected light, and that its + visible forms, waxing and waning month by month from crescent to disk and + from disk to crescent, merely represent our shifting view of its + sun-illumined face. It is difficult to put ourselves in the place of the + ancient observer and realize how little the appearances suggest the actual + fact. That a body of the same structure as the earth should shine with the + radiance of the moon merely because sunlight is reflected from it, is in + itself a supposition seemingly contradicted by ordinary experience. It + required the mind of a philosopher, sustained, perhaps, by some + experimental observations, to conceive the idea that what seems so + obviously bright may be in reality dark. The germ of the conception of + what the philosopher speaks of as the noumena, or actualities, back of + phenomena or appearances, had perhaps this crude beginning. Anaxagoras + could surely point to the moon in support of his seeming paradox that + snow, being really composed of water, which is dark, is in reality black + and not white—a contention to which we shall refer more at length in + a moment. + </p> + <p> + But there is yet another striking thought connected with this new + explanation of the phases of the moon. The explanation implies not merely + the reflection of light by a dark body, but by a dark body of a particular + form. Granted that reflections are in question, no body but a spherical + one could give an appearance which the moon presents. The moon, then, is + not merely a mass of earth, it is a spherical mass of earth. Here there + were no flaws in the reasoning of Anaxagoras. By scientific induction he + passed from observation to explanation. A new and most important element + was added to the science of astronomy. + </p> + <p> + Looking back from the latter-day stand-point, it would seem as if the mind + of the philosopher must have taken one other step: the mind that had + conceived sun, moon, stars, and earth to be of one substance might + naturally, we should think, have reached out to the further induction + that, since the moon is a sphere, the other cosmic bodies, including the + earth, must be spheres also. But generalizer as he was, Anaxagoras was too + rigidly scientific a thinker to make this assumption. The data at his + command did not, as he analyzed them, seem to point to this conclusion. We + have seen that Pythagoras probably, and Parmenides surely, out there in + Italy had conceived the idea of the earth's rotundity, but the Pythagorean + doctrines were not rapidly taken up in the mother-country, and Parmenides, + it must be recalled, was a strict contemporary of Anaxagoras himself. It + is no reproach, therefore, to the Clazomenaean philosopher that he should + have held to the old idea that the earth is flat, or at most a convex disk—the + latter being the Babylonian conception which probably dominated that + Milesian school to which Anaxagoras harked back. + </p> + <p> + Anaxagoras may never have seen an eclipse of the moon, and even if he had + he might have reflected that, from certain directions, a disk may throw + precisely the same shadow as a sphere. Moreover, in reference to the + shadow cast by the earth, there was, so Anaxagoras believed, an + observation open to him nightly which, we may well suppose, was not + without influence in suggesting to his mind the probable shape of the + earth. The Milky Way, which doubtless had puzzled astronomers from the + beginnings of history and which was to continue to puzzle them for many + centuries after the day of Anaxagoras, was explained by the Clazomenaean + philosopher on a theory obviously suggested by the theory of the moon's + phases. Since the earth-like moon shines by reflected light at night, and + since the stars seem obviously brighter on dark nights, Anaxagoras was but + following up a perfectly logical induction when he propounded the theory + that the stars in the Milky Way seem more numerous and brighter than those + of any other part of the heavens, merely because the Milky Way marks the + shadow of the earth. Of course the inference was wrong, so far as the + shadow of the earth is concerned; yet it contained a part truth, the force + of which was never fully recognized until the time of Galileo. This + consists in the assertion that the brightness of the Milky Way is merely + due to the glow of many stars. The shadow-theory of Anaxagoras would + naturally cease to have validity so soon as the sphericity of the earth + was proved, and with it, seemingly, fell for the time the companion theory + that the Milky Way is made up of a multitude of stars. + </p> + <p> + It has been said by a modern critic(1) that the shadow-theory was childish + in that it failed to note that the Milky Way does not follow the course of + the ecliptic. But this criticism only holds good so long as we reflect on + the true character of the earth as a symmetrical body poised in space. It + is quite possible to conceive a body occupying the position of the earth + with reference to the sun which would cast a shadow having such a tenuous + form as the Milky Way presents. Such a body obviously would not be a + globe, but a long-drawn-out, attenuated figure. There is, to be sure, no + direct evidence preserved to show that Anaxagoras conceived the world to + present such a figure as this, but what we know of that philosopher's + close-reasoning, logical mind gives some warrant to the assumption—gratuitous + though in a sense it be—that the author of the theory of the moon's + phases had not failed to ask himself what must be the form of that + terrestrial body which could cast the tenuous shadow of the Milky Way. + Moreover, we must recall that the habitable earth, as known to the Greeks + of that day, was a relatively narrow band of territory, stretching far to + the east and to the west. + </p> + <p> + Anaxagoras as Meteorologist + </p> + <p> + The man who had studied the meteorite of aegospotami, and been put by it + on the track of such remarkable inductions, was, naturally, not oblivious + to the other phenomena of the atmosphere. Indeed, such a mind as that of + Anaxagoras was sure to investigate all manner of natural phenomena, and + almost equally sure to throw new light on any subject that it + investigated. Hence it is not surprising to find Anaxagoras credited with + explaining the winds as due to the rarefactions of the atmosphere produced + by the sun. This explanation gives Anaxagoras full right to be called "the + father of meteorology," a title which, it may be, no one has thought of + applying to him, chiefly because the science of meteorology did not make + its real beginnings until some twenty-four hundred years after the death + of its first great votary. Not content with explaining the winds, this + prototype of Franklin turned his attention even to the tipper atmosphere. + "Thunder," he is reputed to have said, "was produced by the collision of + the clouds, and lightning by the rubbing together of the clouds." We dare + not go so far as to suggest that this implies an association in the mind + of Anaxagoras between the friction of the clouds and the observed + electrical effects generated by the friction of such a substance as amber. + To make such a suggestion doubtless would be to fall victim to the old + familiar propensity to read into Homer things that Homer never knew. Yet + the significant fact remains that Anaxagoras ascribed to thunder and to + lightning their true position as strictly natural phenomena. For him it + was no god that menaced humanity with thundering voice and the flash of + his divine fires from the clouds. Little wonder that the thinker whose + science carried him to such scepticism as this should have felt the wrath + of the superstitious Athenians. + </p> + <p> + Biological Speculations + </p> + <p> + Passing from the phenomena of the air to those of the earth itself, we + learn that Anaxagoras explained an earthquake as being produced by the + returning of air into the earth. We cannot be sure as to the exact meaning + here, though the idea that gases are imprisoned in the substance of the + earth seems not far afield. But a far more remarkable insight than this + would imply was shown by Anaxagoras when he asserted that a certain amount + of air is contained in water, and that fishes breathe this air. The + passage of Aristotle in which this opinion is ascribed to Anaxagoras is of + sufficient interest to be quoted at length: + </p> + <p> + "Democritus, of Abdera," says Aristotle, "and some others, that have + spoken concerning respiration, have determined nothing concerning other + animals, but seem to have supposed that all animals respire. But + Anaxagoras and Diogenes (Apolloniates), who say that all animals respire, + have also endeavored to explain how fishes, and all those animals that + have a hard, rough shell, such as oysters, mussels, etc., respire. And + Anaxagoras, indeed, says that fishes, when they emit water through their + gills, attract air from the mouth to the vacuum in the viscera from the + water which surrounds the mouth; as if air was inherent in the water."(2) + </p> + <p> + It should be recalled that of the three philosophers thus mentioned as + contending that all animals respire, Anaxagoras was the elder; he, + therefore, was presumably the originator of the idea. It will be observed, + too, that Anaxagoras alone is held responsible for the idea that fishes + respire air through their gills, "attracting" it from the water. This + certainly was one of the shrewdest physiological guesses of any age, if it + be regarded as a mere guess. With greater justice we might refer to it as + a profound deduction from the principle of the uniformity of nature. + </p> + <p> + In making such a deduction, Anaxagoras was far in advance of his time as + illustrated by the fact that Aristotle makes the citation we have just + quoted merely to add that "such things are impossible," and to refute + these "impossible" ideas by means of metaphysical reasonings that seemed + demonstrative not merely to himself, but to many generations of his + followers. + </p> + <p> + We are told that Anaxagoras alleged that all animals were originally + generated out of moisture, heat, and earth particles. Just what opinion he + held concerning man's development we are not informed. Yet there is one of + his phrases which suggests—without, perhaps, quite proving—that + he was an evolutionist. This phrase asserts, with insight that is fairly + startling, that man is the most intelligent of animals because he has + hands. The man who could make that assertion must, it would seem, have had + in mind the idea of the development of intelligence through the use of + hands—an idea the full force of which was not evident to subsequent + generations of thinkers until the time of Darwin. + </p> + <p> + Physical Speculations + </p> + <p> + Anaxagoras is cited by Aristotle as believing that "plants are animals and + feel pleasure and pain, inferring this because they shed their leaves and + let them grow again." The idea is fanciful, yet it suggests again a truly + philosophical conception of the unity of nature. The man who could + conceive that idea was but little hampered by traditional conceptions. He + was exercising a rare combination of the rigidly scientific spirit with + the poetical imagination. He who possesses these gifts is sure not to stop + in his questionings of nature until he has found some thinkable + explanation of the character of matter itself. Anaxagoras found such an + explanation, and, as good luck would have it, that explanation has been + preserved. Let us examine his reasoning in some detail. We have already + referred to the claim alleged to have been made by Anaxagoras that snow is + not really white, but black. The philosopher explained his paradox, we are + told, by asserting that snow is really water, and that water is dark, when + viewed under proper conditions—as at the bottom of a well. That idea + contains the germ of the Clazomenaean philosopher's conception of the + nature of matter. Indeed, it is not unlikely that this theory of matter + grew out of his observation of the changing forms of water. He seems + clearly to have grasped the idea that snow on the one hand, and vapor on + the other, are of the same intimate substance as the water from which they + are derived and into which they may be again transformed. The fact that + steam and snow can be changed back into water, and by simple manipulation + cannot be changed into any other substance, finds, as we now believe, its + true explanation in the fact that the molecular structure, as we phrase it—that + is to say, the ultimate particle of which water is composed, is not + changed, and this is precisely the explanation which Anaxagoras gave of + the same phenomena. For him the unit particle of water constituted an + elementary body, uncreated, unchangeable, indestructible. This particle, + in association with like particles, constitutes the substance which we + call water. The same particle in association with particles unlike itself, + might produce totally different substances—as, for example, when + water is taken up by the roots of a plant and becomes, seemingly, a part + of the substance of the plant. But whatever the changed association, so + Anaxagoras reasoned, the ultimate particle of water remains a particle of + water still. And what was true of water was true also, so he conceived, of + every other substance. Gold, silver, iron, earth, and the various + vegetables and animal tissues—in short, each and every one of all + the different substances with which experience makes us familiar, is made + up of unit particles which maintain their integrity in whatever + combination they may be associated. This implies, obviously, a multitude + of primordial particles, each one having an individuality of its own; each + one, like the particle of water already cited, uncreated, unchangeable, + and indestructible. + </p> + <p> + Fortunately, we have the philosopher's own words to guide us as to his + speculations here. The fragments of his writings that have come down to us + (chiefly through the quotations of Simplicius) deal almost exclusively + with these ultimate conceptions of his imagination. In ascribing to him, + then, this conception of diverse, uncreated, primordial elements, which + can never be changed, but can only be mixed together to form substances of + the material world, we are not reading back post-Daltonian knowledge into + the system of Anaxagoras. Here are his words: "The Greeks do not rightly + use the terms 'coming into being' and 'perishing.' For nothing comes into + being, nor, yet, does anything perish; but there is mixture and separation + of things that are. So they would do right in calling 'coming into being' + 'mixture' and 'perishing' 'separation.' For how could hair come from what + is not hair? Or flesh from what is not flesh?" + </p> + <p> + Elsewhere he tells us that (at one stage of the world's development) "the + dense, the moist, the cold, the dark, collected there where now is earth; + the rare, the warm, the dry, the bright, departed towards the further part + of the aether. The earth is condensed out of these things that are + separated, for water is separated from the clouds, and earth from the + water; and from the earth stones are condensed by the cold, and these are + separated farther from the water." Here again the influence of heat and + cold in determining physical qualities is kept pre-eminently in mind. The + dense, the moist, the cold, the dark are contrasted with the rare, the + warm, the dry, and bright; and the formation of stones is spoken of as a + specific condensation due to the influence of cold. Here, then, we have + nearly all the elements of the Daltonian theory of atoms on the one hand, + and the nebular hypothesis of Laplace on the other. But this is not quite + all. In addition to such diverse elementary particles as those of gold, + water, and the rest, Anaxagoras conceived a species of particles differing + from all the others, not merely as they differ from one another, but + constituting a class by themselves; particles infinitely smaller than the + others; particles that are described as infinite, self-powerful, mixed + with nothing, but existing alone. That is to say (interpreting the theory + in the only way that seems plausible), these most minute particles do not + mix with the other primordial particles to form material substances in the + same way in which these mixed with one another. But, on the other hand, + these "infinite, self-powerful, and unmixed" particles commingle + everywhere and in every substance whatever with the mixed particles that + go to make up the substances. + </p> + <p> + There is a distinction here, it will be observed, which at once suggests + the modern distinction between physical processes and chemical processes, + or, putting it otherwise, between molecular processes and atomic + processes; but the reader must be guarded against supposing that + Anaxagoras had any such thought as this in mind. His ultimate mixable + particles can be compared only with the Daltonian atom, not with the + molecule of the modern physicist, and his "infinite, self-powerful, and + unmixable" particles are not comparable with anything but the ether of the + modern physicist, with which hypothetical substance they have many points + of resemblance. But the "infinite, self-powerful, and unmixed" particles + constituting thus an ether-like plenum which permeates all material + structures, have also, in the mind of Anaxagoras, a function which carries + them perhaps a stage beyond the province of the modern ether. For these + "infinite, self powerful, and unmixed" particles are imbued with, and, + indeed, themselves constitute, what Anaxagoras terms nous, a word which + the modern translator has usually paraphrased as "mind." Neither that word + nor any other available one probably conveys an accurate idea of what + Anaxagoras meant to imply by the word nous. For him the word meant not + merely "mind" in the sense of receptive and comprehending intelligence, + but directive and creative intelligence as well. Again let Anaxagoras + speak for himself: "Other things include a portion of everything, but nous + is infinite, and self-powerful, and mixed with nothing, but it exists + alone, itself by itself. For if it were not by itself, but were mixed with + anything else, it would include parts of all things, if it were mixed with + anything; for a portion of everything exists in every thing, as has been + said by me before, and things mingled with it would prevent it from having + power over anything in the same way that it does now that it is alone by + itself. For it is the most rarefied of all things and the purest, and it + has all knowledge in regard to everything and the greatest power; over all + that has life, both greater and less, nous rules. And nous ruled the + rotation of the whole, so that it set it in rotation in the beginning. + First it began the rotation from a small beginning, then more and more was + included in the motion, and yet more will be included. Both the mixed and + the separated and distinct, all things nous recognized. And whatever + things were to be, and whatever things were, as many as are now, and + whatever things shall be, all these nous arranged in order; and it + arranged that rotation, according to which now rotate stars and sun and + moon and air and aether, now that they are separated. Rotation itself + caused the separation, and the dense is separated from the rare, the warm + from the cold, the bright from the dark, the dry from the moist. And when + nous began to set things in motion, there was separation from everything + that was in motion, all this was made distinct. The rotation of the things + that were moved and made distinct caused them to be yet more distinct."(3) + </p> + <p> + Nous, then, as Anaxagoras conceives it, is "the most rarefied of all + things, and the purest, and it has knowledge in regard to everything and + the greatest power; over all that has life, both greater and less, it + rules." But these are postulants of omnipresence and omniscience. In other + words, nous is nothing less than the omnipotent artificer of the material + universe. It lacks nothing of the power of deity, save only that we are + not assured that it created the primordial particles. The creation of + these particles was a conception that for Anaxagoras, as for the modern + Spencer, lay beyond the range of imagination. Nous is the artificer, + working with "uncreated" particles. Back of nous and the particles lies, + for an Anaxagoras as for a Spencer, the Unknowable. But nous itself is the + equivalent of that universal energy of motion which science recognizes as + operating between the particles of matter, and which the theologist + personifies as Deity. It is Pantheistic deity as Anaxagoras conceives it; + his may be called the first scientific conception of a non-anthropomorphic + god. In elaborating this conception Anaxagoras proved himself one of the + most remarkable scientific dreamers of antiquity. To have substituted for + the Greek Pantheon of anthropomorphic deities the conception of a + non-anthropomorphic immaterial and ethereal entity, of all things in the + world "the most rarefied and the purest," is to have performed a feat + which, considering the age and the environment in which it was + accomplished, staggers the imagination. As a strictly scientific + accomplishment the great thinker's conception of primordial elements + contained a germ of the truth which was to lie dormant for 2200 years, but + which then, as modified and vitalized by the genius of Dalton, was to + dominate the new chemical science of the nineteenth century. If there are + intimations that the primordial element of Anaxagoras and of Dalton may + turn out in the near future to be itself a compound, there will still + remain the yet finer particles of the nous of Anaxagoras to baffle the + most subtle analysis of which to-day's science gives us any pre-vision. + All in all, then, the work of Anaxagoras must stand as that of perhaps the + most far-seeing scientific imagination of pre-Socratic antiquity. + </p> + <p> + LEUCIPPUS AND DEMOCRITUS + </p> + <p> + But we must not leave this alluring field of speculation as to the nature + of matter without referring to another scientific guess, which soon + followed that of Anaxagoras and was destined to gain even wider fame, and + which in modern times has been somewhat unjustly held to eclipse the glory + of the other achievement. We mean, of course, the atomic theory of + Leucippus and Democritus. This theory reduced all matter to primordial + elements, called atoms (gr atoma) because they are by hypothesis incapable + of further division. These atoms, making up the entire material universe, + are in this theory conceived as qualitatively identical, differing from + one another only in size and perhaps in shape. The union of + different-sized atoms in endless combinations produces the diverse + substances with which our senses make us familiar. + </p> + <p> + Before we pass to a consideration of this alluring theory, and + particularly to a comparison of it with the theory of Anaxagoras, we must + catch a glimpse of the personality of the men to whom the theory owes its + origin. One of these, Leucippus, presents so uncertain a figure as to be + almost mythical. Indeed, it was long questioned whether such a man had + actually lived, or whether he were not really an invention of his alleged + disciple, Democritus. Latterday scholarship, however, accepts him as a + real personage, though knowing scarcely more of him than that he was the + author of the famous theory with which his name was associated. It is + suggested that he was a wanderer, like most philosophers of his time, and + that later in life he came to Abdera, in Thrace, and through this + circumstance became the teacher of Democritus. This fable answers as well + as another. What we really know is that Democritus himself, through whose + writings and teachings the atomic theory gained vogue, was born in Abdera, + about the year 460 B.C.—that is to say, just about the time when his + great precursor, Anaxagoras, was migrating to Athens. Democritus, like + most others of the early Greek thinkers, lives in tradition as a + picturesque figure. It is vaguely reported that he travelled for a time, + perhaps in the East and in Egypt, and that then he settled down to spend + the remainder of his life in Abdera. Whether or not he visited Athens in + the course of his wanderings we do not know. At Abdera he was revered as a + sage, but his influence upon the practical civilization of the time was + not marked. He was pre-eminently a dreamer and a writer. Like his + confreres of the epoch, he entered all fields of thought. He wrote + voluminously, but, unfortunately, his writings have, for the most part, + perished. The fables and traditions of a later day asserted that + Democritus had voluntarily put out his own eyes that he might turn his + thoughts inward with more concentration. Doubtless this is fiction, yet, + as usual with such fictions, it contains a germ of truth; for we may well + suppose that the promulgator of the atomic theory was a man whose mind was + attracted by the subtleties of thought rather than by the tangibilities of + observation. Yet the term "laughing philosopher," which seems to have been + universally applied to Democritus, suggests a mind not altogether + withdrawn from the world of practicalities. + </p> + <p> + So much for Democritus the man. Let us return now to his theory of atoms. + This theory, it must be confessed, made no very great impression upon his + contemporaries. It found an expositor, a little later, in the philosopher + Epicurus, and later still the poet Lucretius gave it popular expression. + But it seemed scarcely more than the dream of a philosopher or the vagary + of a poet until the day when modern science began to penetrate the + mysteries of matter. When, finally, the researches of Dalton and his + followers had placed the atomic theory on a surer footing as the + foundation of modern chemistry, the ideas of the old laughing philosopher + of Abdera, which all along had been half derisively remembered, were + recalled with a new interest. Now it appeared that these ideas had + curiously foreshadowed nineteenth-century knowledge. It appeared that away + back in the fifth century B.C. a man had dreamed out a conception of the + ultimate nature of matter which had waited all these centuries for + corroboration. And now the historians of philosophy became more than + anxious to do justice to the memory of Democritus. + </p> + <p> + It is possible that this effort at poetical restitution has carried the + enthusiast too far. There is, indeed, a curious suggestiveness in the + theory of Democritus; there is philosophical allurement in his reduction + of all matter to a single element; it contains, it may be, not merely a + germ of the science of the nineteenth-century chemistry, but perhaps the + germs also of the yet undeveloped chemistry of the twentieth century. Yet + we dare suggest that in their enthusiasm for the atomic theory of + Democritus the historians of our generation have done something less than + justice to that philosopher's precursor, Anaxagoras. And one suspects that + the mere accident of a name has been instrumental in producing this + result. Democritus called his primordial element an atom; Anaxagoras, too, + conceived a primordial element, but he called it merely a seed or thing; + he failed to christen it distinctively. Modern science adopted the word + atom and gave it universal vogue. It owed a debt of gratitude to + Democritus for supplying it the word, but it somewhat overpaid the debt in + too closely linking the new meaning of the word with its old original one. + For, let it be clearly understood, the Daltonian atom is not precisely + comparable with the atom of Democritus. The atom, as Democritus conceived + it, was monistic; all atoms, according to this hypothesis, are of the same + substance; one atom differs from another merely in size and shape, but not + at all in quality. But the Daltonian hypothesis conceived, and nearly all + the experimental efforts of the nineteenth century seemed to prove, that + there are numerous classes of atoms, each differing in its very essence + from the others. + </p> + <p> + As the case stands to-day the chemist deals with seventy-odd substances, + which he calls elements. Each one of these substances is, as he conceives + it, made up of elementary atoms having a unique personality, each + differing in quality from all the others. As far as experiment has thus + far safely carried us, the atom of gold is a primordial element which + remains an atom of gold and nothing else, no matter with what other atoms + it is associated. So, too, of the atom of silver, or zinc, or sodium—in + short, of each and every one of the seventy-odd elements. There are, + indeed, as we shall see, experiments that suggest the dissolution of the + atom—that suggest, in short, that the Daltonian atom is misnamed, + being a structure that may, under certain conditions, be broken asunder. + But these experiments have, as yet, the warrant rather of philosophy than + of pure science, and to-day we demand that the philosophy of science shall + be the handmaid of experiment. + </p> + <p> + When experiment shall have demonstrated that the Daltonian atom is a + compound, and that in truth there is but a single true atom, which, + combining with its fellows perhaps in varying numbers and in different + special relations, produces the Daltonian atoms, then the philosophical + theory of monism will have the experimental warrant which to-day it lacks; + then we shall be a step nearer to the atom of Democritus in one direction, + a step farther away in the other. We shall be nearer, in that the + conception of Democritus was, in a sense, monistic; farther away, in that + all the atoms of Democritus, large and small alike, were considered as + permanently fixed in size. Democritus postulated all his atoms as of the + same substance, differing not at all in quality; yet he was obliged to + conceive that the varying size of the atoms gave to them varying functions + which amounted to qualitative differences. He might claim for his largest + atom the same quality of substance as for his smallest, but so long as he + conceived that the large atoms, when adjusted together to form a tangible + substance, formed a substance different in quality from the substance + which the small atoms would make up when similarly grouped, this + concession amounts to the predication of difference of quality between the + atoms themselves. The entire question reduces itself virtually to a + quibble over the word quality, So long as one atom conceived to be + primordial and indivisible is conceded to be of such a nature as + necessarily to produce a different impression on our senses, when grouped + with its fellows, from the impression produced by other atoms when + similarly grouped, such primordial atoms do differ among themselves in + precisely the same way for all practical purposes as do the primordial + elements of Anaxagoras. + </p> + <p> + The monistic conception towards which twentieth-century chemistry seems to + be carrying us may perhaps show that all the so-called atoms are + compounded of a single element. All the true atoms making up that element + may then properly be said to have the same quality, but none the less will + it remain true that the combinations of that element that go to make up + the different Daltonian atoms differ from one another in quality in + precisely the same sense in which such tangible substances as gold, and + oxygen, and mercury, and diamonds differ from one another. In the last + analysis of the monistic philosophy, there is but one substance and one + quality in the universe. In the widest view of that philosophy, gold and + oxygen and mercury and diamonds are one substance, and, if you please, one + quality. But such refinements of analysis as this are for the + transcendental philosopher, and not for the scientist. Whatever the + allurement of such reasoning, we must for the purpose of science let words + have a specific meaning, nor must we let a mere word-jugglery blind us to + the evidence of facts. That was the rock on which Greek science foundered; + it is the rock which the modern helmsman sometimes finds it difficult to + avoid. And if we mistake not, this case of the atom of Democritus is + precisely a case in point. Because Democritus said that his atoms did not + differ in quality, the modern philosopher has seen in his theory the + essentials of monism; has discovered in it not merely a forecast of the + chemistry of the nineteenth century, but a forecast of the hypothetical + chemistry of the future. And, on the other hand, because Anaxagoras + predicted a different quality for his primordial elements, the philosopher + of our day has discredited the primordial element of Anaxagoras. + </p> + <p> + Yet if our analysis does not lead us astray, the theory of Democritus was + not truly monistic; his indestructible atoms, differing from one another + in size and shape, utterly incapable of being changed from the form which + they had maintained from the beginning, were in reality as truly and + primordially different as are the primordial elements of Anaxagoras. In + other words, the atom of Democritus is nothing less than the primordial + seed of Anaxagoras, a little more tangibly visualized and given a + distinctive name. Anaxagoras explicitly conceived his elements as + invisibly small, as infinite in number, and as made up of an indefinite + number of kinds—one for each distinctive substance in the world. But + precisely the same postulates are made of the atom of Democritus. These + also are invisibly small; these also are infinite in number; these also + are made up of an indefinite number of kinds, corresponding with the + observed difference of substances in the world. "Primitive seeds," or + "atoms," were alike conceived to be primordial, un-changeable, and + indestructible. Wherein then lies the difference? We answer, chiefly in a + name; almost solely in the fact that Anaxagoras did not attempt to + postulate the physical properties of the elements beyond stating that each + has a distinctive personality, while Democritus did attempt to postulate + these properties. He, too, admitted that each kind of element has its + distinctive personality, and he attempted to visualize and describe the + characteristics of the personality. + </p> + <p> + Thus while Anaxagoras tells us nothing of his elements except that they + differ from one another, Democritus postulates a difference in size, + imagines some elements as heavier and some as lighter, and conceives even + that the elements may be provided with projecting hooks, with the aid of + which they link themselves one with another. No one to-day takes these + crude visualizings seriously as to their details. The sole element of + truth which these dreamings contain, as distinguishing them from the + dreamings of Anaxagoras, is in the conception that the various atoms + differ in size and weight. Here, indeed, is a vague fore-shadowing of that + chemistry of form which began to come into prominence towards the close of + the nineteenth century. To have forecast even dimly this newest phase of + chemical knowledge, across the abyss of centuries, is indeed a feat to put + Democritus in the front rank of thinkers. But this estimate should not + blind us to the fact that the pre-vision of Democritus was but a slight + elaboration of a theory which had its origin with another thinker. The + association between Anaxagoras and Democritus cannot be directly traced, + but it is an association which the historian of ideas should never for a + moment forget. If we are not to be misled by mere word-jugglery, we shall + recognize the founder of the atomic theory of matter in Anaxagoras; its + expositors along slightly different lines in Leucippus and Democritus; its + re-discoverer of the nineteenth century in Dalton. All in all, then, just + as Anaxagoras preceded Democritus in time, so must he take precedence over + him also as an inductive thinker, who carried the use of the scientific + imagination to its farthest reach. + </p> + <p> + An analysis of the theories of the two men leads to somewhat the same + conclusion that might be reached from a comparison of their lives. + Anaxagoras was a sceptical, experimental scientist, gifted also with the + prophetic imagination. He reasoned always from the particular to the + general, after the manner of true induction, and he scarcely took a step + beyond the confines of secure induction. True scientist that he was, he + could content himself with postulating different qualities for his + elements, without pretending to know how these qualities could be defined. + His elements were by hypothesis invisible, hence he would not attempt to + visualize them. Democritus, on the other hand, refused to recognize this + barrier. Where he could not know, he still did not hesitate to guess. Just + as he conceived his atom of a definite form with a definite structure, + even so he conceived that the atmosphere about him was full of invisible + spirits; he accepted the current superstitions of his time. Like the + average Greeks of his day, he even believed in such omens as those + furnished by inspecting the entrails of a fowl. These chance bits of + biography are weather-vanes of the mind of Democritus. They tend to + substantiate our conviction that Democritus must rank below Anaxagoras as + a devotee of pure science. But, after all, such comparisons and estimates + as this are utterly futile. The essential fact for us is that here, in the + fifth century before our era, we find put forward the most penetrating + guess as to the constitution of matter that the history of ancient thought + has to present to us. In one direction, the avenue of progress is barred; + there will be no farther step that way till we come down the centuries to + the time of Dalton. + </p> + <p> + HIPPOCRATES AND GREEK MEDICINE + </p> + <p> + These studies of the constitution of matter have carried us to the limits + of the field of scientific imagination in antiquity; let us now turn + sharply and consider a department of science in which theory joins hands + with practicality. Let us witness the beginnings of scientific + therapeutics. + </p> + <p> + Medicine among the early Greeks, before the time of Hippocrates, was a + crude mixture of religion, necromancy, and mysticism. Temples were erected + to the god of medicine, aesculapius, and sick persons made their way, or + were carried, to these temples, where they sought to gain the favor of the + god by suitable offerings, and learn the way to regain their health + through remedies or methods revealed to them in dreams by the god. When + the patient had been thus cured, he placed a tablet in the temple + describing his sickness, and telling by what method the god had cured him. + He again made suitable offerings at the temple, which were sometimes in + the form of gold or silver representations of the diseased organ—a + gold or silver model of a heart, hand, foot, etc. + </p> + <p> + Nevertheless, despite this belief in the supernatural, many drugs and + healing lotions were employed, and the Greek physicians possessed + considerable skill in dressing wounds and bandaging. But they did not + depend upon these surgical dressings alone, using with them certain + appropriate prayers and incantations, recited over the injured member at + the time of applying the dressings. + </p> + <p> + Even the very early Greeks had learned something of anatomy. The daily + contact with wounds and broken bones must of necessity lead to a crude + understanding of anatomy in general. The first Greek anatomist, however, + who is recognized as such, is said to have been Alcmaeon. He is said to + have made extensive dissections of the lower animals, and to have + described many hitherto unknown structures, such as the optic nerve and + the Eustachian canal—the small tube leading into the throat from the + ear. He is credited with many unique explanations of natural phenomena, + such as, for example, the explanation that "hearing is produced by the + hollow bone behind the ear; for all hollow things are sonorous." He was a + rationalist, and he taught that the brain is the organ of mind. The + sources of our information about his work, however, are unreliable. + </p> + <p> + Democedes, who lived in the sixth century B.C., is the first physician of + whom we have any trustworthy history. We learn from Herodotus that he came + from Croton to aegina, where, in recognition of his skill, he was + appointed medical officer of the city. From aegina he was called to Athens + at an increased salary, and later was in charge of medical affairs in + several other Greek cities. He was finally called to Samos by the tyrant + Polycrates, who reigned there from about 536 to 522 B.C. But on the death + of Polycrates, who was murdered by the Persians, Democedes became a slave. + His fame as a physician, however, had reached the ears of the Persian + monarch, and shortly after his capture he was permitted to show his skill + upon King Darius himself. The Persian monarch was suffering from a + sprained ankle, which his Egyptian surgeons had been unable to cure. + Democedes not only cured the injured member but used his influence in + saving the lives of his Egyptian rivals, who had been condemned to death + by the king. + </p> + <p> + At another time he showed his skill by curing the queen, who was suffering + from a chronic abscess of long standing. This so pleased the monarch that + he offered him as a reward anything he might desire, except his liberty. + But the costly gifts of Darius did not satisfy him so long as he remained + a slave; and determined to secure his freedom at any cost, he volunteered + to lead some Persian spies into his native country, promising to use his + influence in converting some of the leading men of his nation to the + Persian cause. Laden with the wealth that had been heaped upon him by + Darius, he set forth upon his mission, but upon reaching his native city + of Croton he threw off his mask, renounced his Persian mission, and became + once more a free Greek. + </p> + <p> + While the story of Democedes throws little light upon the medical + practices of the time, it shows that paid city medical officers existed in + Greece as early as the fifth and sixth centuries B.C. Even then there were + different "schools" of medicine, whose disciples disagreed radically in + their methods of treating diseases; and there were also specialists in + certain diseases, quacks, and charlatans. Some physicians depended + entirely upon external lotions for healing all disorders; others were + "hydrotherapeutists" or "bath-physicians"; while there were a host of + physicians who administered a great variety of herbs and drugs. There were + also magicians who pretended to heal by sorcery, and great numbers of + bone-setters, oculists, and dentists. + </p> + <p> + Many of the wealthy physicians had hospitals, or clinics, where patients + were operated upon and treated. They were not hospitals in our modern + understanding of the term, but were more like dispensaries, where patients + were treated temporarily, but were not allowed to remain for any length of + time. Certain communities established and supported these dispensaries for + the care of the poor. + </p> + <p> + But anything approaching a rational system of medicine was not + established, until Hippocrates of Cos, the "father of medicine," came upon + the scene. In an age that produced Phidias, Lysias, Herodotus, Sophocles, + and Pericles, it seems but natural that the medical art should find an + exponent who would rise above superstitious dogmas and lay the foundation + for a medical science. His rejection of the supernatural alone stamps the + greatness of his genius. But, besides this, he introduced more detailed + observation of diseases, and demonstrated the importance that attaches to + prognosis. + </p> + <p> + Hippocrates was born at Cos, about 460 B.C., but spent most of his life at + Larissa, in Thessaly. He was educated as a physician by his father, and + travelled extensively as an itinerant practitioner for several years. His + travels in different climates and among many different people undoubtedly + tended to sharpen his keen sense of observation. He was a practical + physician as well as a theorist, and, withal, a clear and concise writer. + "Life is short," he says, "opportunity fleeting, judgment difficult, + treatment easy, but treatment after thought is proper and profitable." + </p> + <p> + His knowledge of anatomy was necessarily very imperfect, and was gained + largely from his predecessors, to whom he gave full credit. Dissections of + the human body were forbidden him, and he was obliged to confine his + experimental researches to operations on the lower animals. His knowledge + of the structure and arrangement of the bones, however, was fairly + accurate, but the anatomy of the softer tissues, as he conceived it, was a + queer jumbling together of blood-vessels, muscles, and tendons. He does + refer to "nerves," to be sure, but apparently the structures referred to + are the tendons and ligaments, rather than the nerves themselves. He was + better acquainted with the principal organs in the cavities of the body, + and knew, for example, that the heart is divided into four cavities, two + of which he supposed to contain blood, and the other two air. + </p> + <p> + His most revolutionary step was his divorcing of the supernatural from the + natural, and establishing the fact that disease is due to natural causes + and should be treated accordingly. The effect of such an attitude can + hardly be over-estimated. The establishment of such a theory was naturally + followed by a close observation as to the course of diseases and the + effects of treatment. To facilitate this, he introduced the custom of + writing down his observations as he made them—the "clinical history" + of the case. Such clinical records are in use all over the world to-day, + and their importance is so obvious that it is almost incomprehensible that + they should have fallen into disuse shortly after the time of Hippocrates, + and not brought into general use again until almost two thousand years + later. + </p> + <p> + But scarcely less important than his recognition of disease as a natural + phenomenon was the importance he attributed to prognosis. Prognosis, in + the sense of prophecy, was common before the time of Hippocrates. But + prognosis, as he practised it and as we understand it to-day, is prophecy + based on careful observation of the course of diseases—something + more than superstitious conjecture. + </p> + <p> + Although Hippocratic medicine rested on the belief in natural causes, + nevertheless, dogma and theory held an important place. The humoral theory + of disease was an all-important one, and so fully was this theory accepted + that it influenced the science of medicine all through succeeding + centuries. According to this celebrated theory there are four humors in + the body—blood, phlegm, yellow bile, and black bile. When these + humors are mixed in exact proportions they constitute health; but any + deviations from these proportions produce disease. In treating diseases + the aim of the physician was to discover which of these humors were out of + proportion and to restore them to their natural equilibrium. It was in the + methods employed in this restitution, rather than a disagreement about the + humors themselves, that resulted in the various "schools" of medicine. + </p> + <p> + In many ways the surgery of Hippocrates showed a better understanding of + the structure of the organs than of their functions. Some of the surgical + procedures as described by him are followed, with slight modifications, + to-day. Many of his methods were entirely lost sight of until modern + times, and one, the treatment of dislocation of the outer end of the + collar-bone, was not revived until some time in the eighteenth century. + </p> + <p> + Hippocrates, it seems, like modern physicians, sometimes suffered from the + ingratitude of his patients. "The physician visits a patient suffering + from fever or a wound, and prescribes for him," he says; "on the next day, + if the patient feels worse the blame is laid upon the physician; if, on + the other hand, he feels better, nature is extolled, and the physician + reaps no praise." The essence of this has been repeated in rhyme and prose + by writers in every age and country, but the "father of medicine" cautions + physicians against allowing it to influence their attitude towards their + profession. + </p> + <p> + <a name="link2H_4_0010" id="link2H_4_0010"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + VIII. POST-SOCRATIC SCIENCE AT ATHENS—PLATO, ARISTOTLE, AND + THEOPHRASTUS + </h2> + <p> + Doubtless it has been noticed that our earlier scientists were as far + removed as possible from the limitations of specialism. In point of fact, + in this early day, knowledge had not been classified as it came to be + later on. The philosopher was, as his name implied, a lover of knowledge, + and he did not find it beyond the reach of his capacity to apply himself + to all departments of the field of human investigation. It is nothing + strange to discover that Anaximander and the Pythagoreans and Anaxagoras + have propounded theories regarding the structure of the cosmos, the origin + and development of animals and man, and the nature of matter itself. + Nowadays, so enormously involved has become the mass of mere facts + regarding each of these departments of knowledge that no one man has the + temerity to attempt to master them all. But it was different in those days + of beginnings. Then the methods of observation were still crude, and it + was quite the custom for a thinker of forceful personality to find an + eager following among disciples who never thought of putting his theories + to the test of experiment. The great lesson that true science in the last + resort depends upon observation and measurement, upon compass and balance, + had not yet been learned, though here and there a thinker like Anaxagoras + had gained an inkling of it. + </p> + <p> + For the moment, indeed, there in Attica, which was now, thanks to that + outburst of Periclean culture, the centre of the world's civilization, the + trend of thought was to take quite another direction. The very year which + saw the birth of Democritus at Abdera, and of Hippocrates, marked also the + birth, at Athens, of another remarkable man, whose influence it would + scarcely be possible to over-estimate. This man was Socrates. The main + facts of his history are familiar to every one. It will be recalled that + Socrates spent his entire life in Athens, mingling everywhere with the + populace; haranguing, so the tradition goes, every one who would listen; + inculcating moral lessons, and finally incurring the disapprobation of at + least a voting majority of his fellow-citizens. He gathered about him a + company of remarkable men with Plato at their head, but this could not + save him from the disapprobation of the multitudes, at whose hands he + suffered death, legally administered after a public trial. The facts at + command as to certain customs of the Greeks at this period make it + possible to raise a question as to whether the alleged "corruption of + youth," with which Socrates was charged, may not have had a different + implication from what posterity has preferred to ascribe to it. But this + thought, almost shocking to the modern mind and seeming altogether + sacrilegious to most students of Greek philosophy, need not here detain + us; neither have we much concern in the present connection with any part + of the teaching of the martyred philosopher. For the historian of + metaphysics, Socrates marks an epoch, but for the historian of science he + is a much less consequential figure. + </p> + <p> + Similarly regarding Plato, the aristocratic Athenian who sat at the feet + of Socrates, and through whose writings the teachings of the master found + widest currency. Some students of philosophy find in Plato "the greatest + thinker and writer of all time."(1) The student of science must recognize + in him a thinker whose point of view was essentially non-scientific; one + who tended always to reason from the general to the particular rather than + from the particular to the general. Plato's writings covered almost the + entire field of thought, and his ideas were presented with such literary + charm that successive generations of readers turned to them with + unflagging interest, and gave them wide currency through copies that + finally preserved them to our own time. Thus we are not obliged in his + case, as we are in the case of every other Greek philosopher, to estimate + his teachings largely from hearsay evidence. Plato himself speaks to us + directly. It is true, the literary form which he always adopted, namely, + the dialogue, does not give quite the same certainty as to when he is + expressing his own opinions that a more direct narrative would have given; + yet, in the main, there is little doubt as to the tenor of his own + opinions—except, indeed, such doubt as always attaches to the + philosophical reasoning of the abstract thinker. + </p> + <p> + What is chiefly significant from our present standpoint is that the great + ethical teacher had no significant message to give the world regarding the + physical sciences. He apparently had no sharply defined opinions as to the + mechanism of the universe; no clear conception as to the origin or + development of organic beings; no tangible ideas as to the problems of + physics; no favorite dreams as to the nature of matter. Virtually his back + was turned on this entire field of thought. He was under the sway of those + innate ideas which, as we have urged, were among the earliest inductions + of science. But he never for a moment suspected such an origin for these + ideas. He supposed his conceptions of being, his standards of ethics, to + lie back of all experience; for him they were the most fundamental and + most dependable of facts. He criticised Anaxagoras for having tended to + deduce general laws from observation. As we moderns see it, such criticism + is the highest possible praise. It is a criticism that marks the + distinction between the scientist who is also a philosopher and the + philosopher who has but a vague notion of physical science. Plato seemed, + indeed, to realize the value of scientific investigation; he referred to + the astronomical studies of the Egyptians and Chaldeans, and spoke + hopefully of the results that might accrue were such studies to be taken + up by that Greek mind which, as he justly conceived, had the power to + vitalize and enrich all that it touched. But he told here of what he would + have others do, not of what he himself thought of doing. His voice was + prophetic, but it stimulated no worker of his own time. + </p> + <p> + Plato himself had travelled widely. It is a familiar legend that he lived + for years in Egypt, endeavoring there to penetrate the mysteries of + Egyptian science. It is said even that the rudiments of geometry which he + acquired there influenced all his later teachings. But be that as it may, + the historian of science must recognize in the founder of the Academy a + moral teacher and metaphysical dreamer and sociologist, but not, in the + modern acceptance of the term, a scientist. Those wider phases of + biological science which find their expression in metaphysics, in ethics, + in political economy, lie without our present scope; and for the + development of those subjects with which we are more directly concerned, + Plato, like his master, has a negative significance. + </p> + <p> + ARISTOTLE (384-322 B.C.) + </p> + <p> + When we pass to that third great Athenian teacher, Aristotle, the case is + far different. Here was a man whose name was to be received as almost a + synonym for Greek science for more than a thousand years after his death. + All through the Middle Ages his writings were to be accepted as virtually + the last word regarding the problems of nature. We shall see that his + followers actually preferred his mandate to the testimony of their own + senses. We shall see, further, that modern science progressed somewhat in + proportion as it overthrew the Aristotelian dogmas. But the traditions of + seventeen or eighteen centuries are not easily set aside, and it is + perhaps not too much to say that the name of Aristotle stands, even in our + own time, as vaguely representative in the popular mind of all that was + highest and best in the science of antiquity. Yet, perhaps, it would not + be going too far to assert that something like a reversal of this judgment + would be nearer the truth. Aristotle did, indeed, bring together a great + mass of facts regarding animals in his work on natural history, which, + being preserved, has been deemed to entitle its author to be called the + "father of zoology." But there is no reason to suppose that any + considerable portion of this work contained matter that was novel, or + recorded observations that were original with Aristotle; and the + classifications there outlined are at best but a vague foreshadowing of + the elaboration of the science. Such as it is, however, the natural + history stands to the credit of the Stagirite. He must be credited, too, + with a clear enunciation of one most important scientific doctrine—namely, + the doctrine of the spherical figure of the earth. We have already seen + that this theory originated with the Pythagorean philosophers out in + Italy. We have seen, too, that the doctrine had not made its way in Attica + in the time of Anaxagoras. But in the intervening century it had gained + wide currency, else so essentially conservative a thinker as Aristotle + would scarcely have accepted it. He did accept it, however, and gave the + doctrine clearest and most precise expression. Here are his words:(2) + </p> + <p> + "As to the figure of the earth it must necessarily be spherical.... If it + were not so, the eclipses of the moon would not have such sections as they + have. For in the configurations in the course of a month the deficient + part takes all different shapes; it is straight, and concave, and convex; + but in eclipses it always has the line of divisions convex; wherefore, + since the moon is eclipsed in consequence of the interposition of the + earth, the periphery of the earth must be the cause of this by having a + spherical form. And again, from the appearance of the stars it is clear, + not only that the earth is round, but that its size is not very large; for + when we make a small removal to the south or the north, the circle of the + horizon becomes palpably different, so that the stars overhead undergo a + great change, and are not the same to those that travel in the north and + to the south. For some stars are seen in Egypt or at Cyprus, but are not + seen in the countries to the north of these; and the stars that in the + north are visible while they make a complete circuit, there undergo a + setting. So that from this it is manifest, not only that the form of the + earth is round, but also that it is a part of a not very large sphere; for + otherwise the difference would not be so obvious to persons making so + small a change of place. Wherefore we may judge that those persons who + connect the region in the neighborhood of the pillars of Hercules with + that towards India, and who assert that in this way the sea is one, do not + assert things very improbable. They confirm this conjecture moreover by + the elephants, which are said to be of the same species towards each + extreme; as if this circumstance was a consequence of the conjunction of + the extremes. The mathematicians who try to calculate the measure of the + circumference, make it amount to four hundred thousand stadia; whence we + collect that the earth is not only spherical, but is not large compared + with the magnitude of the other stars." + </p> + <p> + But in giving full meed of praise to Aristotle for the promulgation of + this doctrine of the sphericity of the earth, it must unfortunately be + added that the conservative philosopher paused without taking one other + important step. He could not accept, but, on the contrary, he expressly + repudiated, the doctrine of the earth's motion. We have seen that this + idea also was a part of the Pythagorean doctrine, and we shall have + occasion to dwell more at length on this point in a succeeding chapter. It + has even been contended by some critics that it was the adverse conviction + of the Peripatetic philosopher which, more than any other single + influence, tended to retard the progress of the true doctrine regarding + the mechanism of the heavens. Aristotle accepted the sphericity of the + earth, and that doctrine became a commonplace of scientific knowledge, and + so continued throughout classical antiquity. But Aristotle rejected the + doctrine of the earth's motion, and that doctrine, though promulgated + actively by a few contemporaries and immediate successors of the + Stagirite, was then doomed to sink out of view for more than a thousand + years. If it be a correct assumption that the influence of Aristotle was, + in a large measure, responsible for this result, then we shall perhaps not + be far astray in assuming that the great founder of the Peripatetic school + was, on the whole, more instrumental in retarding the progress of + astronomical science that any other one man that ever lived. + </p> + <p> + The field of science in which Aristotle was pre-eminently a pathfinder is + zoology. His writings on natural history have largely been preserved, and + they constitute by far the most important contribution to the subject that + has come down to us from antiquity. They show us that Aristotle had gained + possession of the widest range of facts regarding the animal kingdom, and, + what is far more important, had attempted to classify these facts. In so + doing he became the founder of systematic zoology. Aristotle's + classification of the animal kingdom was known and studied throughout the + Middle Ages, and, in fact, remained in vogue until superseded by that of + Cuvier in the nineteenth century. It is not to be supposed that all the + terms of Aristotle's classification originated with him. Some of the + divisions are too patent to have escaped the observation of his + predecessors. Thus, for example, the distinction between birds and fishes + as separate classes of animals is so obvious that it must appeal to a + child or to a savage. But the efforts of Aristotle extended, as we shall + see, to less patent generalizations. At the very outset, his grand + division of the animal kingdom into blood-bearing and bloodless animals + implies a very broad and philosophical conception of the entire animal + kingdom. The modern physiologist does not accept the classification, + inasmuch as it is now known that colorless fluids perform the functions of + blood for all the lower organisms. But the fact remains that Aristotle's + grand divisions correspond to the grand divisions of the Lamarckian system—vertebrates + and invertebrates—which every one now accepts. Aristotle, as we have + said, based his classification upon observation of the blood; Lamarck was + guided by a study of the skeleton. The fact that such diverse points of + view could direct the observer towards the same result gives, + inferentially, a suggestive lesson in what the modern physiologist calls + the homologies of parts of the organism. + </p> + <p> + Aristotle divides his so-called blood-bearing animals into five classes: + (1) Four-footed animals that bring forth their young alive; (2) birds; (3) + egg-laying four-footed animals (including what modern naturalists call + reptiles and amphibians); (4) whales and their allies; (5) fishes. This + classification, as will be observed, is not so very far afield from the + modern divisions into mammals, birds, reptiles, amphibians, and fishes. + That Aristotle should have recognized the fundamental distinction between + fishes and the fish-like whales, dolphins, and porpoises proves the far + from superficial character of his studies. Aristotle knew that these + animals breathe by means of lungs and that they produce living young. He + recognized, therefore, their affinity with his first class of animals, + even if he did not, like the modern naturalist, consider these affinities + close enough to justify bringing the two types together into a single + class. + </p> + <p> + The bloodless animals were also divided by Aristotle into five classes—namely: + (1) Cephalopoda (the octopus, cuttle-fish, etc.); (2) weak-shelled animals + (crabs, etc.); (3) insects and their allies (including various forms, such + as spiders and centipedes, which the modern classifier prefers to place by + themselves); (4) hard-shelled animals (clams, oysters, snails, etc.); (5) + a conglomerate group of marine forms, including star-fish, sea-urchins, + and various anomalous forms that were regarded as linking the animal to + the vegetable worlds. This classification of the lower forms of animal + life continued in vogue until Cuvier substituted for it his famous + grouping into articulates, mollusks, and radiates; which grouping in turn + was in part superseded later in the nineteenth century. + </p> + <p> + What Aristotle did for the animal kingdom his pupil, Theophrastus, did in + some measure for the vegetable kingdom. Theophrastus, however, was much + less a classifier than his master, and his work on botany, called The + Natural History of Development, pays comparatively slight attention to + theoretical questions. It deals largely with such practicalities as the + making of charcoal, of pitch, and of resin, and the effects of various + plants on the animal organism when taken as foods or as medicines. In this + regard the work of Theophrastus, is more nearly akin to the natural + history of the famous Roman compiler, Pliny. It remained, however, + throughout antiquity as the most important work on its subject, and it + entitles Theophrastus to be called the "father of botany." Theophrastus + deals also with the mineral kingdom after much the same fashion, and here + again his work is the most notable that was produced in antiquity. + </p> + <p> + <a name="link2H_4_0011" id="link2H_4_0011"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + </h2> + <p> + We are entering now upon the most important scientific epoch of antiquity. + When Aristotle and Theophrastus passed from the scene, Athens ceased to be + in any sense the scientific centre of the world. That city still retained + its reminiscent glory, and cannot be ignored in the history of culture, + but no great scientific leader was ever again to be born or to take up his + permanent abode within the confines of Greece proper. With almost + cataclysmic suddenness, a new intellectual centre appeared on the south + shore of the Mediterranean. This was the city of Alexandria, a city which + Alexander the Great had founded during his brief visit to Egypt, and which + became the capital of Ptolemy Soter when he chose Egypt as his portion of + the dismembered empire of the great Macedonian. Ptolemy had been with his + master in the East, and was with him in Babylonia when he died. He had + therefore come personally in contact with Babylonian civilization, and we + cannot doubt that this had a most important influence upon his life, and + through him upon the new civilization of the West. In point of culture, + Alexandria must be regarded as the successor of Babylon, scarcely less + directly than of Greece. Following the Babylonian model, Ptolemy erected a + great museum and began collecting a library. Before his death it was said + that he had collected no fewer than two hundred thousand manuscripts. He + had gathered also a company of great teachers and founded a school of + science which, as has just been said, made Alexandria the culture-centre + of the world. + </p> + <p> + Athens in the day of her prime had known nothing quite like this. Such + private citizens as Aristotle are known to have had libraries, but there + were no great public collections of books in Athens, or in any other part + of the Greek domain, until Ptolemy founded his famous library. As is well + known, such libraries had existed in Babylonia for thousands of years. The + character which the Ptolemaic epoch took on was no doubt due to Babylonian + influence, but quite as much to the personal experience of Ptolemy himself + as an explorer in the Far East. The marvellous conquering journey of + Alexander had enormously widened the horizon of the Greek geographer, and + stimulated the imagination of all ranks of the people, It was but natural, + then, that geography and its parent science astronomy should occupy the + attention of the best minds in this succeeding epoch. In point of fact, + such a company of star-gazers and earth-measurers came upon the scene in + this third century B.C. as had never before existed anywhere in the world. + The whole trend of the time was towards mechanics. It was as if the + greatest thinkers had squarely faced about from the attitude of the + mystical philosophers of the preceding century, and had set themselves the + task of solving all the mechanical riddles of the universe, They no longer + troubled themselves about problems of "being" and "becoming"; they gave + but little heed to metaphysical subtleties; they demanded that their + thoughts should be gauged by objective realities. Hence there arose a + succession of great geometers, and their conceptions were applied to the + construction of new mechanical contrivances on the one hand, and to the + elaboration of theories of sidereal mechanics on the other. + </p> + <p> + The wonderful company of men who performed the feats that are about to be + recorded did not all find their home in Alexandria, to be sure; but they + all came more or less under the Alexandrian influence. We shall see that + there are two other important centres; one out in Sicily, almost at the + confines of the Greek territory in the west; the other in Asia Minor, + notably on the island of Samos—the island which, it will be + recalled, was at an earlier day the birthplace of Pythagoras. But whereas + in the previous century colonists from the confines of the civilized world + came to Athens, now all eyes turned towards Alexandria, and so improved + were the facilities for communication that no doubt the discoveries of one + coterie of workers were known to all the others much more quickly than had + ever been possible before. We learn, for example, that the studies of + Aristarchus of Samos were definitely known to Archimedes of Syracuse, out + in Sicily. Indeed, as we shall see, it is through a chance reference + preserved in one of the writings of Archimedes that one of the most + important speculations of Aristarchus is made known to us. This + illustrates sufficiently the intercommunication through which the thought + of the Alexandrian epoch was brought into a single channel. We no longer, + as in the day of the earlier schools of Greek philosophy, have isolated + groups of thinkers. The scientific drama is now played out upon a single + stage; and if we pass, as we shall in the present chapter, from Alexandria + to Syracuse and from Syracuse to Samos, the shift of scenes does no + violence to the dramatic unities. + </p> + <p> + Notwithstanding the number of great workers who were not properly + Alexandrians, none the less the epoch is with propriety termed + Alexandrian. Not merely in the third century B.C., but throughout the + lapse of at least four succeeding centuries, the city of Alexander and the + Ptolemies continued to hold its place as the undisputed culture-centre of + the world. During that period Rome rose to its pinnacle of glory and began + to decline, without ever challenging the intellectual supremacy of the + Egyptian city. We shall see, in a later chapter, that the Alexandrian + influences were passed on to the Mohammedan conquerors, and every one is + aware that when Alexandria was finally overthrown its place was taken by + another Greek city, Byzantium or Constantinople. But that transfer did not + occur until Alexandria had enjoyed a longer period of supremacy as an + intellectual centre than had perhaps ever before been granted to any city, + with the possible exception of Babylon. + </p> + <p> + EUCLID (ABOUT 300 B.C.) + </p> + <p> + Our present concern is with that first wonderful development of scientific + activity which began under the first Ptolemy, and which presents, in the + course of the first century of Alexandrian influence, the most remarkable + coterie of scientific workers and thinkers that antiquity produced. The + earliest group of these new leaders in science had at its head a man whose + name has been a household word ever since. This was Euclid, the father of + systematic geometry. Tradition has preserved to us but little of the + personality of this remarkable teacher; but, on the other hand, his most + important work has come down to us in its entirety. The Elements of + Geometry, with which the name of Euclid is associated in the mind of every + school-boy, presented the chief propositions of its subject in so simple + and logical a form that the work remained a textbook everywhere for more + than two thousand years. Indeed it is only now beginning to be superseded. + It is not twenty years since English mathematicians could deplore the fact + that, despite certain rather obvious defects of the work of Euclid, no + better textbook than this was available. Euclid's work, of course, gives + expression to much knowledge that did not originate with him. We have + already seen that several important propositions of geometry had been + developed by Thales, and one by Pythagoras, and that the rudiments of the + subject were at least as old as Egyptian civilization. Precisely how much + Euclid added through his own investigations cannot be ascertained. It + seems probable that he was a diffuser of knowledge rather than an + originator, but as a great teacher his fame is secure. He is credited with + an epigram which in itself might insure him perpetuity of fame: "There is + no royal road to geometry," was his answer to Ptolemy when that ruler had + questioned whether the Elements might not be simplified. Doubtless this, + like most similar good sayings, is apocryphal; but whoever invented it has + made the world his debtor. + </p> + <p> + HEROPHILUS AND ERASISTRATUS + </p> + <p> + The catholicity of Ptolemy's tastes led him, naturally enough, to + cultivate the biological no less than the physical sciences. In particular + his influence permitted an epochal advance in the field of medicine. Two + anatomists became famous through the investigations they were permitted to + make under the patronage of the enlightened ruler. These earliest of + really scientific investigators of the mechanism of the human body were + named Herophilus and Erasistratus. These two anatomists gained their + knowledge by the dissection of human bodies (theirs are the first records + that we have of such practices), and King Ptolemy himself is said to have + been present at some of these dissections. They were the first to discover + that the nerve-trunks have their origin in the brain and spinal cord, and + they are credited also with the discovery that these nerve-trunks are of + two different kinds—one to convey motor, and the other sensory + impulses. They discovered, described, and named the coverings of the + brain. The name of Herophilus is still applied by anatomists, in honor of + the discoverer, to one of the sinuses or large canals that convey the + venous blood from the head. Herophilus also noticed and described four + cavities or ventricles in the brain, and reached the conclusion that one + of these ventricles was the seat of the soul—a belief shared until + comparatively recent times by many physiologists. He made also a careful + and fairly accurate study of the anatomy of the eye, a greatly improved + the old operation for cataract. + </p> + <p> + With the increased knowledge of anatomy came also corresponding advances + in surgery, and many experimental operations are said to have been + performed upon condemned criminals who were handed over to the surgeons by + the Ptolemies. While many modern writers have attempted to discredit these + assertions, it is not improbable that such operations were performed. In + an age when human life was held so cheap, and among a people accustomed to + torturing condemned prisoners for comparatively slight offences, it is not + unlikely that the surgeons were allowed to inflict perhaps less painful + tortures in the cause of science. Furthermore, we know that condemned + criminals were sometimes handed over to the medical profession to be + "operated upon and killed in whatever way they thought best" even as late + as the sixteenth century. Tertullian(1) probably exaggerates, however, + when he puts the number of such victims in Alexandria at six hundred. + </p> + <p> + Had Herophilus and Erasistratus been as happy in their deductions as to + the functions of the organs as they were in their knowledge of anatomy, + the science of medicine would have been placed upon a very high plane even + in their time. Unfortunately, however, they not only drew erroneous + inferences as to the functions of the organs, but also disagreed radically + as to what functions certain organs performed, and how diseases should be + treated, even when agreeing perfectly on the subject of anatomy itself. + Their contribution to the knowledge of the scientific treatment of + diseases holds no such place, therefore, as their anatomical + investigations. + </p> + <p> + Half a century after the time of Herophilus there appeared a Greek + physician, Heraclides, whose reputation in the use of drugs far surpasses + that of the anatomists of the Alexandrian school. His reputation has been + handed down through the centuries as that of a physician, rather than a + surgeon, although in his own time he was considered one of the great + surgeons of the period. Heraclides belonged to the "Empiric" school, which + rejected anatomy as useless, depending entirely on the use of drugs. He is + thought to have been the first physician to point out the value of opium + in certain painful diseases. His prescription of this drug for certain + cases of "sleeplessness, spasm, cholera, and colic," shows that his use of + it was not unlike that of the modern physician in certain cases; and his + treatment of fevers, by keeping the patient's head cool and facilitating + the secretions of the body, is still recognized as "good practice." He + advocated a free use of liquids in quenching the fever patient's thirst—a + recognized therapeutic measure to-day, but one that was widely condemned a + century ago. + </p> + <p> + ARCHIMEDES OF SYRACUSE AND THE FOUNDATION OF MECHANICS + </p> + <p> + We do not know just when Euclid died, but as he was at the height of his + fame in the time of Ptolemy I., whose reign ended in the year 285 B.C., it + is hardly probable that he was still living when a young man named + Archimedes came to Alexandria to study. Archimedes was born in the Greek + colony of Syracuse, on the island of Sicily, in the year 287 B.C. When he + visited Alexandria he probably found Apollonius of Perga, the pupil of + Euclid, at the head of the mathematical school there. Just how long + Archimedes remained at Alexandria is not known. When he had satisfied his + curiosity or completed his studies, he returned to Syracuse and spent his + life there, chiefly under the patronage of King Hiero, who seems fully to + have appreciated his abilities. + </p> + <p> + Archimedes was primarily a mathematician. Left to his own devices, he + would probably have devoted his entire time to the study of geometrical + problems. But King Hiero had discovered that his protege had wonderful + mechanical ingenuity, and he made good use of this discovery. Under stress + of the king's urgings, the philosopher was led to invent a great variety + of mechanical contrivances, some of them most curious ones. Antiquity + credited him with the invention of more than forty machines, and it is + these, rather than his purely mathematical discoveries, that gave his name + popular vogue both among his contemporaries and with posterity. Every one + has heard of the screw of Archimedes, through which the paradoxical effect + was produced of making water seem to flow up hill. The best idea of this + curious mechanism is obtained if one will take in hand an ordinary + corkscrew, and imagine this instrument to be changed into a hollow tube, + retaining precisely the same shape but increased to some feet in length + and to a proportionate diameter. If one will hold the corkscrew in a + slanting direction and turn it slowly to the right, supposing that the + point dips up a portion of water each time it revolves, one can in + imagination follow the flow of that portion of water from spiral to + spiral, the water always running downward, of course, yet paradoxically + being lifted higher and higher towards the base of the corkscrew, until + finally it pours out (in the actual Archimedes' tube) at the top. There is + another form of the screw in which a revolving spiral blade operates + within a cylinder, but the principle is precisely the same. With either + form water may be lifted, by the mere turning of the screw, to any desired + height. The ingenious mechanism excited the wonder of the contemporaries + of Archimedes, as well it might. More efficient devices have superseded it + in modern times, but it still excites the admiration of all who examine + it, and its effects seem as paradoxical as ever. + </p> + <p> + Some other of the mechanisms of Archimedes have been made known to + successive generations of readers through the pages of Polybius and + Plutarch. These are the devices through which Archimedes aided King Hiero + to ward off the attacks of the Roman general Marcellus, who in the course + of the second Punic war laid siege to Syracuse. + </p> + <p> + Plutarch, in his life of Marcellus, describes the Roman's attack and + Archimedes' defence in much detail. Incidentally he tells us also how + Archimedes came to make the devices that rendered the siege so famous: + </p> + <p> + "Marcellus himself, with threescore galleys of five rowers at every bank, + well armed and full of all sorts of artillery and fireworks, did assault + by sea, and rowed hard to the wall, having made a great engine and device + of battery, upon eight galleys chained together, to batter the wall: + trusting in the great multitude of his engines of battery, and to all such + other necessary provision as he had for wars, as also in his own + reputation. But Archimedes made light account of all his devices, as + indeed they were nothing comparable to the engines himself had invented. + This inventive art to frame instruments and engines (which are called + mechanical, or organical, so highly commended and esteemed of all sorts of + people) was first set forth by Architas, and by Eudoxus: partly to + beautify a little the science of geometry by this fineness, and partly to + prove and confirm by material examples and sensible instruments, certain + geometrical conclusions, where of a man cannot find out the conceivable + demonstrations by enforced reasons and proofs. As that conclusion which + instructeth one to search out two lines mean proportional, which cannot be + proved by reason demonstrative, and yet notwithstanding is a principle and + an accepted ground for many things which are contained in the art of + portraiture. Both of them have fashioned it to the workmanship of certain + instruments, called mesolabes or mesographs, which serve to find these + mean lines proportional, by drawing certain curve lines, and overthwart + and oblique sections. But after that Plato was offended with them, and + maintained against them, that they did utterly corrupt and disgrace, the + worthiness and excellence of geometry, making it to descend from things + not comprehensible and without body, unto things sensible and material, + and to bring it to a palpable substance, where the vile and base handiwork + of man is to be employed: since that time, I say, handicraft, or the art + of engines, came to be separated from geometry, and being long time + despised by the philosophers, it came to be one of the warlike arts. + </p> + <p> + "But Archimedes having told King Hiero, his kinsman and friend, that it + was possible to remove as great a weight as he would, with as little + strength as he listed to put to it: and boasting himself thus (as they + report of him) and trusting to the force of his reasons, wherewith he + proved this conclusion, that if there were another globe of earth, he was + able to remove this of ours, and pass it over to the other: King Hiero + wondering to hear him, required him to put his device in execution, and to + make him see by experience, some great or heavy weight removed, by little + force. So Archimedes caught hold with a book of one of the greatest + carects, or hulks of the king (that to draw it to the shore out of the + water required a marvellous number of people to go about it, and was + hardly to be done so) and put a great number of men more into her, than + her ordinary burden: and he himself sitting alone at his ease far off, + without any straining at all, drawing the end of an engine with many + wheels and pulleys, fair and softly with his hand, made it come as gently + and smoothly to him, as it had floated in the sea. The king wondering to + see the sight, and knowing by proof the greatness of his art; be prayed + him to make him some engines, both to assault and defend, in all manner of + sieges and assaults. So Archimedes made him many engines, but King Hiero + never occupied any of them, because he reigned the most part of his time + in peace without any wars. But this provision and munition of engines, + served the Syracusan's turn marvellously at that time: and not only the + provision of the engines ready made, but also the engineer and work-master + himself, that had invented them. + </p> + <p> + "Now the Syracusans, seeing themselves assaulted by the Romans, both by + sea and by land, were marvellously perplexed, and could not tell what to + say, they were so afraid: imagining it was impossible for them to + withstand so great an army. But when Archimedes fell to handling his + engines, and to set them at liberty, there flew in the air infinite kinds + of shot, and marvellous great stones, with an incredible noise and force + on the sudden, upon the footmen that came to assault the city by land, + bearing down, and tearing in pieces all those which came against them, or + in what place soever they lighted, no earthly body being able to resist + the violence of so heavy a weight: so that all their ranks were + marvellously disordered. And as for the galleys that gave assault by sea, + some were sunk with long pieces of timber like unto the yards of ships, + whereto they fasten their sails, which were suddenly blown over the walls + with force of their engines into their galleys, and so sunk them by their + over great weight." + </p> + <p> + Polybius describes what was perhaps the most important of these + contrivances, which was, he tells us, "a band of iron, hanging by a chain + from the beak of a machine, which was used in the following manner. The + person who, like a pilot, guided the beak, having let fall the hand, and + catched hold of the prow of any vessel, drew down the opposite end of the + machine that was on the inside of the walls. And when the vessel was thus + raised erect upon its stem, the machine itself was held immovable; but, + the chain being suddenly loosened from the beak by the means of pulleys, + some of the vessels were thrown upon their sides, others turned with the + bottom upwards; and the greatest part, as the prows were plunged from a + considerable height into the sea, were filled with water, and all that + were on board thrown into tumult and disorder. + </p> + <p> + "Marcellus was in no small degree embarrassed," Polybius continues, "when + he found himself encountered in every attempt by such resistance. He + perceived that all his efforts were defeated with loss; and were even + derided by the enemy. But, amidst all the anxiety that he suffered, he + could not help jesting upon the inventions of Archimedes. This man, said + he, employs our ships as buckets to draw water: and boxing about our + sackbuts, as if they were unworthy to be associated with him, drives them + from his company with disgrace. Such was the success of the siege on the + side of the sea." + </p> + <p> + Subsequently, however, Marcellus took the city by strategy, and Archimedes + was killed, contrary, it is said, to the express orders of Marcellus. + "Syracuse being taken," says Plutarch, "nothing grieved Marcellus more + than the loss of Archimedes. Who, being in his study when the city was + taken, busily seeking out by himself the demonstration of some geometrical + proposition which he had drawn in figure, and so earnestly occupied + therein, as he neither saw nor heard any noise of enemies that ran up and + down the city, and much less knew it was taken: he wondered when he saw a + soldier by him, that bade him go with him to Marcellus. Notwithstanding, + he spake to the soldier, and bade him tarry until he had done his + conclusion, and brought it to demonstration: but the soldier being angry + with his answer, drew out his sword and killed him. Others say, that the + Roman soldier when he came, offered the sword's point to him, to kill him: + and that Archimedes when he saw him, prayed him to hold his hand a little, + that he might not leave the matter he looked for imperfect, without + demonstration. But the soldier making no reckoning of his speculation, + killed him presently. It is reported a third way also, saying that certain + soldiers met him in the streets going to Marcellus, carrying certain + mathematical instruments in a little pretty coffer, as dials for the sun, + spheres, and angles, wherewith they measure the greatness of the body of + the sun by view: and they supposing he had carried some gold or silver, or + other precious jewels in that little coffer, slew him for it. But it is + most certain that Marcellus was marvellously sorry for his death, and ever + after hated the villain that slew him, as a cursed and execrable person: + and how he had made also marvellous much afterwards of Archimedes' kinsmen + for his sake." + </p> + <p> + We are further indebted to Plutarch for a summary of the character and + influence of Archimedes, and for an interesting suggestion as to the + estimate which the great philosopher put upon the relative importance of + his own discoveries. "Notwithstanding Archimedes had such a great mind, + and was so profoundly learned, having hidden in him the only treasure and + secrets of geometrical inventions: as he would never set forth any book + how to make all these warlike engines, which won him at that time the fame + and glory, not of man's knowledge, but rather of divine wisdom. But he + esteeming all kind of handicraft and invention to make engines, and + generally all manner of sciences bringing common commodity by the use of + them, to be but vile, beggarly, and mercenary dross: employed his wit and + study only to write things, the beauty and subtlety whereof were not + mingled anything at all with necessity. For all that he hath written, are + geometrical propositions, which are without comparison of any other + writings whatsoever: because the subject where of they treat, doth appear + by demonstration, the maker gives them the grace and the greatness, and + the demonstration proving it so exquisitely, with wonderful reason and + facility, as it is not repugnable. For in all geometry are not to be found + more profound and difficult matters written, in more plain and simple + terms, and by more easy principles, than those which he hath invented. Now + some do impute this, to the sharpness of his wit and understanding, which + was a natural gift in him: others do refer it to the extreme pains he + took, which made these things come so easily from him, that they seemed as + if they had been no trouble to him at all. For no man living of himself + can devise the demonstration of his propositions, what pains soever he + take to seek it: and yet straight so soon as he cometh to declare and open + it, every man then imagineth with himself he could have found it out well + enough, he can then so plainly make demonstration of the thing he meaneth + to show. And therefore that methinks is likely to be true, which they + write of him: that he was so ravished and drunk with the sweet enticements + of this siren, which as it were lay continually with him, as he forgot his + meat and drink, and was careless otherwise of himself, that oftentimes his + servants got him against his will to the baths to wash and anoint him: and + yet being there, he would ever be drawing out of the geometrical figures, + even in the very imbers of the chimney. And while they were anointing of + him with oils and sweet savours, with his finger he did draw lines upon + his naked body: so far was he taken from himself, and brought into an + ecstasy or trance, with the delight he had in the study of geometry, and + truly ravished with the love of the Muses. But amongst many notable things + he devised, it appeareth, that he most esteemed the demonstration of the + proportion between the cylinder (to wit, the round column) and the sphere + or globe contained in the same: for he prayed his kinsmen and friends, + that after his death they would put a cylinder upon his tomb, containing a + massy sphere, with an inscription of the proportion, whereof the continent + exceedeth the thing contained."(2) + </p> + <p> + It should be observed that neither Polybius nor Plutarch mentions the use + of burning-glasses in connection with the siege of Syracuse, nor indeed + are these referred to by any other ancient writer of authority. + Nevertheless, a story gained credence down to a late day to the effect + that Archimedes had set fire to the fleet of the enemy with the aid of + concave mirrors. An experiment was made by Sir Isaac Newton to show the + possibility of a phenomenon so well in accord with the genius of + Archimedes, but the silence of all the early authorities makes it more + than doubtful whether any such expedient was really adopted. + </p> + <p> + It will be observed that the chief principle involved in all these + mechanisms was a capacity to transmit great power through levers and + pulleys, and this brings us to the most important field of the Syracusan + philosopher's activity. It was as a student of the lever and the pulley + that Archimedes was led to some of his greatest mechanical discoveries. He + is even credited with being the discoverer of the compound pulley. More + likely he was its developer only, since the principle of the pulley was + known to the old Babylonians, as their sculptures testify. But there is no + reason to doubt the general outlines of the story that Archimedes + astounded King Hiero by proving that, with the aid of multiple pulleys, + the strength of one man could suffice to drag the largest ship from its + moorings. + </p> + <p> + The property of the lever, from its fundamental principle, was studied by + him, beginning with the self-evident fact that "equal bodies at the ends + of the equal arms of a rod, supported on its middle point, will balance + each other"; or, what amounts to the same thing stated in another way, a + regular cylinder of uniform matter will balance at its middle point. From + this starting-point he elaborated the subject on such clear and + satisfactory principles that they stand to-day practically unchanged and + with few additions. From all his studies and experiments he finally + formulated the principle that "bodies will be in equilibrio when their + distance from the fulcrum or point of support is inversely as their + weight." He is credited with having summed up his estimate of the + capabilities of the lever with the well-known expression, "Give me a + fulcrum on which to rest or a place on which to stand, and I will move the + earth." + </p> + <p> + But perhaps the feat of all others that most appealed to the imagination + of his contemporaries, and possibly also the one that had the greatest + bearing upon the position of Archimedes as a scientific discoverer, was + the one made familiar through the tale of the crown of Hiero. This crown, + so the story goes, was supposed to be made of solid gold, but King Hiero + for some reason suspected the honesty of the jeweller, and desired to know + if Archimedes could devise a way of testing the question without injuring + the crown. Greek imagination seldom spoiled a story in the telling, and in + this case the tale was allowed to take on the most picturesque of phases. + The philosopher, we are assured, pondered the problem for a long time + without succeeding, but one day as he stepped into a bath, his attention + was attracted by the overflow of water. A new train of ideas was started + in his ever-receptive brain. Wild with enthusiasm he sprang from the bath, + and, forgetting his robe, dashed along the streets of Syracuse, shouting: + "Eureka! Eureka!" (I have found it!) The thought that had come into his + mind was this: That any heavy substance must have a bulk proportionate to + its weight; that gold and silver differ in weight, bulk for bulk, and that + the way to test the bulk of such an irregular object as a crown was to + immerse it in water. The experiment was made. A lump of pure gold of the + weight of the crown was immersed in a certain receptacle filled with + water, and the overflow noted. Then a lump of pure silver of the same + weight was similarly immersed; lastly the crown itself was immersed, and + of course—for the story must not lack its dramatic sequel—was + found bulkier than its weight of pure gold. Thus the genius that could + balk warriors and armies could also foil the wiles of the silversmith. + </p> + <p> + Whatever the truth of this picturesque narrative, the fact remains that + some, such experiments as these must have paved the way for perhaps the + greatest of all the studies of Archimedes—those that relate to the + buoyancy of water. Leaving the field of fable, we must now examine these + with some precision. Fortunately, the writings of Archimedes himself are + still extant, in which the results of his remarkable experiments are + related, so we may present the results in the words of the discoverer. + </p> + <p> + Here they are: "First: The surface of every coherent liquid in a state of + rest is spherical, and the centre of the sphere coincides with the centre + of the earth. Second: A solid body which, bulk for bulk, is of the same + weight as a liquid, if immersed in the liquid will sink so that the + surface of the body is even with the surface of the liquid, but will not + sink deeper. Third: Any solid body which is lighter, bulk for bulk, than a + liquid, if placed in the liquid will sink so deep as to displace the mass + of liquid equal in weight to another body. Fourth: If a body which is + lighter than a liquid is forcibly immersed in the liquid, it will be + pressed upward with a force corresponding to the weight of a like volume + of water, less the weight of the body itself. Fifth: Solid bodies which, + bulk for bulk, are heavier than a liquid, when immersed in the liquid sink + to the bottom, but become in the liquid as much lighter as the weight of + the displaced water itself differs from the weight of the solid." These + propositions are not difficult to demonstrate, once they are conceived, + but their discovery, combined with the discovery of the laws of statics + already referred to, may justly be considered as proving Archimedes the + most inventive experimenter of antiquity. + </p> + <p> + Curiously enough, the discovery which Archimedes himself is said to have + considered the most important of all his innovations is one that seems + much less striking. It is the answer to the question, What is the relation + in bulk between a sphere and its circumscribing cylinder? Archimedes finds + that the ratio is simply two to three. We are not informed as to how he + reached his conclusion, but an obvious method would be to immerse a ball + in a cylindrical cup. The experiment is one which any one can make for + himself, with approximate accuracy, with the aid of a tumbler and a solid + rubber ball or a billiard-ball of just the right size. Another geometrical + problem which Archimedes solved was the problem as to the size of a + triangle which has equal area with a circle; the answer being, a triangle + having for its base the circumference of the circle and for its altitude + the radius. Archimedes solved also the problem of the relation of the + diameter of the circle to its circumference; his answer being a close + approximation to the familiar 3.1416, which every tyro in geometry will + recall as the equivalent of pi. + </p> + <p> + Numerous other of the studies of Archimedes having reference to conic + sections, properties of curves and spirals, and the like, are too + technical to be detailed here. The extent of his mathematical knowledge, + however, is suggested by the fact that he computed in great detail the + number of grains of sand that would be required to cover the sphere of the + sun's orbit, making certain hypothetical assumptions as to the size of the + earth and the distance of the sun for the purposes of argument. + Mathematicians find his computation peculiarly interesting because it + evidences a crude conception of the idea of logarithms. From our present + stand-point, the paper in which this calculation is contained has + considerable interest because of its assumptions as to celestial + mechanics. Thus Archimedes starts out with the preliminary assumption that + the circumference of the earth is less than three million stadia. It must + be understood that this assumption is purely for the sake of argument. + Archimedes expressly states that he takes this number because it is "ten + times as large as the earth has been supposed to be by certain + investigators." Here, perhaps, the reference is to Eratosthenes, whose + measurement of the earth we shall have occasion to revert to in a moment. + Continuing, Archimedes asserts that the sun is larger than the earth, and + the earth larger than the moon. In this assumption, he says, he is + following the opinion of the majority of astronomers. In the third place, + Archimedes assumes that the diameter of the sun is not more than thirty + times greater than that of the moon. Here he is probably basing his + argument upon another set of measurements of Aristarchus, to which, also, + we shall presently refer more at length. In reality, his assumption is + very far from the truth, since the actual diameter of the sun, as we now + know, is something like four hundred times that of the moon. Fourth, the + circumference of the sun is greater than one side of the thousand-faced + figure inscribed in its orbit. The measurement, it is expressly stated, is + based on the measurements of Aristarchus, who makes the diameter of the + sun 1/170 of its orbit. Archimedes adds, however, that he himself has + measured the angle and that it appears to him to be less than 1/164, and + greater than 1/200 part of the orbit. That is to say, reduced to modern + terminology, he places the limit of the sun's apparent size between + thirty-three minutes and twenty-seven minutes of arc. As the real diameter + is thirty-two minutes, this calculation is surprisingly exact, considering + the implements then at command. But the honor of first making it must be + given to Aristarchus and not to Archimedes. + </p> + <p> + We need not follow Archimedes to the limits of his incomprehensible + numbers of sand-grains. The calculation is chiefly remarkable because it + was made before the introduction of the so-called Arabic numerals had + simplified mathematical calculations. It will be recalled that the Greeks + used letters for numerals, and, having no cipher, they soon found + themselves in difficulties when large numbers were involved. The Roman + system of numerals simplified the matter somewhat, but the beautiful + simplicity of the decimal system did not come into vogue until the Middle + Ages, as we shall see. Notwithstanding the difficulties, however, + Archimedes followed out his calculations to the piling up of bewildering + numbers, which the modern mathematician finds to be the consistent outcome + of the problem he had set himself. + </p> + <p> + But it remains to notice the most interesting feature of this document in + which the calculation of the sand-grains is contained. "It was known to + me," says Archimedes, "that most astronomers understand by the expression + 'world' (universe) a ball of which the centre is the middle point of the + earth, and of which the radius is a straight line between the centre of + the earth and the sun." Archimedes himself appears to accept this opinion + of the majority,—it at least serves as well as the contrary + hypothesis for the purpose of his calculation,—but he goes on to + say: "Aristarchus of Samos, in his writing against the astronomers, seeks + to establish the fact that the world is really very different from this. + He holds the opinion that the fixed stars and the sun are immovable and + that the earth revolves in a circular line about the sun, the sun being at + the centre of this circle." This remarkable bit of testimony establishes + beyond question the position of Aristarchus of Samos as the Copernicus of + antiquity. We must make further inquiry as to the teachings of the man who + had gained such a remarkable insight into the true system of the heavens. + </p> + <p> + ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY + </p> + <p> + It appears that Aristarchus was a contemporary of Archimedes, but the + exact dates of his life are not known. He was actively engaged in making + astronomical observations in Samos somewhat before the middle of the third + century B.C.; in other words, just at the time when the activities of the + Alexandrian school were at their height. Hipparchus, at a later day, was + enabled to compare his own observations with those made by Aristarchus, + and, as we have just seen, his work was well known to so distant a + contemporary as Archimedes. Yet the facts of his life are almost a blank + for us, and of his writings only a single one has been preserved. That + one, however, is a most important and interesting paper on the + measurements of the sun and the moon. Unfortunately, this paper gives us + no direct clew as to the opinions of Aristarchus concerning the relative + positions of the earth and sun. But the testimony of Archimedes as to this + is unequivocal, and this testimony is supported by other rumors in + themselves less authoritative. + </p> + <p> + In contemplating this astronomer of Samos, then, we are in the presence of + a man who had solved in its essentials the problem of the mechanism of the + solar system. It appears from the words of Archimedes that Aristarchus; + had propounded his theory in explicit writings. Unquestionably, then, he + held to it as a positive doctrine, not as a mere vague guess. We shall + show, in a moment, on what grounds he based his opinion. Had his teaching + found vogue, the story of science would be very different from what it is. + We should then have no tale to tell of a Copernicus coming upon the scene + fully seventeen hundred years later with the revolutionary doctrine that + our world is not the centre of the universe. We should not have to tell of + the persecution of a Bruno or of a Galileo for teaching this doctrine in + the seventeenth century of an era which did not begin till two hundred + years after the death of Aristarchus. But, as we know, the teaching of the + astronomer of Samos did not win its way. The old conservative geocentric + doctrine, seemingly so much more in accordance with the every-day + observations of mankind, supported by the majority of astronomers with the + Peripatetic philosophers at their head, held its place. It found fresh + supporters presently among the later Alexandrians, and so fully eclipsed + the heliocentric view that we should scarcely know that view had even + found an advocate were it not for here and there such a chance record as + the phrases we have just quoted from Archimedes. Yet, as we now see, the + heliocentric doctrine, which we know to be true, had been thought out and + advocated as the correct theory of celestial mechanics by at least one + worker of the third century B.C. Such an idea, we may be sure, did not + spring into the mind of its originator except as the culmination of a long + series of observations and inferences. The precise character of the + evolution we perhaps cannot trace, but its broader outlines are open to + our observation, and we may not leave so important a topic without at + least briefly noting them. + </p> + <p> + Fully to understand the theory of Aristarchus, we must go back a century + or two and recall that as long ago as the time of that other great native + of Samos, Pythagoras, the conception had been reached that the earth is in + motion. We saw, in dealing with Pythagoras, that we could not be sure as + to precisely what he himself taught, but there is no question that the + idea of the world's motion became from an early day a so-called + Pythagorean doctrine. While all the other philosophers, so far as we know, + still believed that the world was flat, the Pythagoreans out in Italy + taught that the world is a sphere and that the apparent motions of the + heavenly bodies are really due to the actual motion of the earth itself. + They did not, however, vault to the conclusion that this true motion of + the earth takes place in the form of a circuit about the sun. Instead of + that, they conceived the central body of the universe to be a great fire, + invisible from the earth, because the inhabited side of the terrestrial + ball was turned away from it. The sun, it was held, is but a great mirror, + which reflects the light from the central fire. Sun and earth alike + revolve about this great fire, each in its own orbit. Between the earth + and the central fire there was, curiously enough, supposed to be an + invisible earthlike body which was given the name of Anticthon, or + counter-earth. This body, itself revolving about the central fire, was + supposed to shut off the central light now and again from the sun or from + the moon, and thus to account for certain eclipses for which the shadow of + the earth did not seem responsible. It was, perhaps, largely to account + for such eclipses that the counter-earth was invented. But it is supposed + that there was another reason. The Pythagoreans held that there is a + peculiar sacredness in the number ten. Just as the Babylonians of the + early day and the Hegelian philosophers of a more recent epoch saw a + sacred connection between the number seven and the number of planetary + bodies, so the Pythagoreans thought that the universe must be arranged in + accordance with the number ten. Their count of the heavenly bodies, + including the sphere of the fixed stars, seemed to show nine, and the + counter-earth supplied the missing body. + </p> + <p> + The precise genesis and development of this idea cannot now be followed, + but that it was prevalent about the fifth century B.C. as a Pythagorean + doctrine cannot be questioned. Anaxagoras also is said to have taken + account of the hypothetical counter-earth in his explanation of eclipses; + though, as we have seen, he probably did not accept that part of the + doctrine which held the earth to be a sphere. The names of Philolaus and + Heraclides have been linked with certain of these Pythagorean doctrines. + Eudoxus, too, who, like the others, lived in Asia Minor in the fourth + century B.C., was held to have made special studies of the heavenly + spheres and perhaps to have taught that the earth moves. So, too, Nicetas + must be named among those whom rumor credited with having taught that the + world is in motion. In a word, the evidence, so far as we can garner it + from the remaining fragments, tends to show that all along, from the time + of the early Pythagoreans, there had been an undercurrent of opinion in + the philosophical world which questioned the fixity of the earth; and it + would seem that the school of thinkers who tended to accept the + revolutionary view centred in Asia Minor, not far from the early home of + the founder of the Pythagorean doctrines. It was not strange, then, that + the man who was finally to carry these new opinions to their logical + conclusion should hail from Samos. + </p> + <p> + But what was the support which observation could give to this new, strange + conception that the heavenly bodies do not in reality move as they seem to + move, but that their apparent motion is due to the actual revolution of + the earth? It is extremely difficult for any one nowadays to put himself + in a mental position to answer this question. We are so accustomed to + conceive the solar system as we know it to be, that we are wont to forget + how very different it is from what it seems. Yet one needs but to glance + up at the sky, and then to glance about one at the solid earth, to grant, + on a moment's reflection, that the geocentric idea is of all others the + most natural; and that to conceive the sun as the actual Centre of the + solar system is an idea which must look for support to some other evidence + than that which ordinary observation can give. Such was the view of most + of the ancient philosophers, and such continued to be the opinion of the + majority of mankind long after the time of Copernicus. We must not forget + that even so great an observing astronomer as Tycho Brahe, so late as the + seventeenth century, declined to accept the heliocentric theory, though + admitting that all the planets except the earth revolve about the sun. We + shall see that before the Alexandrian school lost its influence a + geocentric scheme had been evolved which fully explained all the apparent + motions of the heavenly bodies. All this, then, makes us but wonder the + more that the genius of an Aristarchus could give precedence to scientific + induction as against the seemingly clear evidence of the senses. + </p> + <p> + What, then, was the line of scientific induction that led Aristarchus to + this wonderful goal? Fortunately, we are able to answer that query, at + least in part. Aristarchus gained his evidence through some wonderful + measurements. First, he measured the disks of the sun and the moon. This, + of course, could in itself give him no clew to the distance of these + bodies, and therefore no clew as to their relative size; but in attempting + to obtain such a clew he hit upon a wonderful yet altogether simple + experiment. It occurred to him that when the moon is precisely + dichotomized—that is to say, precisely at the half-the line of + vision from the earth to the moon must be precisely at right angles with + the line of light passing from the sun to the moon. At this moment, then, + the imaginary lines joining the sun, the moon, and the earth, make a right + angle triangle. But the properties of the right-angle triangle had long + been studied and were well under stood. One acute angle of such a triangle + determines the figure of the triangle itself. We have already seen that + Thales, the very earliest of the Greek philosophers, measured the distance + of a ship at sea by the application of this principle. Now Aristarchus + sights the sun in place of Thales' ship, and, sighting the moon at the + same time, measures the angle and establishes the shape of his right-angle + triangle. This does not tell him the distance of the sun, to be sure, for + he does not know the length of his base-line—that is to say, of the + line between the moon and the earth. But it does establish the relation of + that base-line to the other lines of the triangle; in other words, it + tells him the distance of the sun in terms of the moon's distance. As + Aristarchus strikes the angle, it shows that the sun is eighteen times as + distant as the moon. Now, by comparing the apparent size of the sun with + the apparent size of the moon—which, as we have seen, Aristarchus + has already measured—he is able to tell us that, the sun is "more + than 5832 times, and less than 8000" times larger than the moon; though + his measurements, taken by themselves, give no clew to the actual bulk of + either body. These conclusions, be it understood, are absolutely valid + inferences—nay, demonstrations—from the measurements involved, + provided only that these measurements have been correct. Unfortunately, + the angle of the triangle we have just seen measured is exceedingly + difficult to determine with accuracy, while at the same time, as a + moment's reflection will show, it is so large an angle that a very slight + deviation from the truth will greatly affect the distance at which its + line joins the other side of the triangle. Then again, it is virtually + impossible to tell the precise moment when the moon is at half, as the + line it gives is not so sharp that we can fix it with absolute accuracy. + There is, moreover, another element of error due to the refraction of + light by the earth's atmosphere. The experiment was probably made when the + sun was near the horizon, at which time, as we now know, but as + Aristarchus probably did not suspect, the apparent displacement of the + sun's position is considerable; and this displacement, it will be + observed, is in the direction to lessen the angle in question. + </p> + <p> + In point of fact, Aristarchus estimated the angle at eighty-seven degrees. + Had his instrument been more precise, and had he been able to take account + of all the elements of error, he would have found it eighty-seven degrees + and fifty-two minutes. The difference of measurement seems slight; but it + sufficed to make the computations differ absurdly from the truth. The sun + is really not merely eighteen times but more than two hundred times the + distance of the moon, as Wendelein discovered on repeating the experiment + of Aristarchus about two thousand years later. Yet this discrepancy does + not in the least take away from the validity of the method which + Aristarchus employed. Moreover, his conclusion, stated in general terms, + was perfectly correct: the sun is many times more distant than the moon + and vastly larger than that body. Granted, then, that the moon is, as + Aristarchus correctly believed, considerably less in size than the earth, + the sun must be enormously larger than the earth; and this is the vital + inference which, more than any other, must have seemed to Aristarchus to + confirm the suspicion that the sun and not the earth is the centre of the + planetary system. It seemed to him inherently improbable that an + enormously large body like the sun should revolve about a small one such + as the earth. And again, it seemed inconceivable that a body so distant as + the sun should whirl through space so rapidly as to make the circuit of + its orbit in twenty-four hours. But, on the other hand, that a small body + like the earth should revolve about the gigantic sun seemed inherently + probable. This proposition granted, the rotation of the earth on its axis + follows as a necessary consequence in explanation of the seeming motion of + the stars. Here, then, was the heliocentric doctrine reduced to a virtual + demonstration by Aristarchus of Samos, somewhere about the middle of the + third century B.C. + </p> + <p> + It must be understood that in following out the steps of reasoning by + which we suppose Aristarchus to have reached so remarkable a conclusion, + we have to some extent guessed at the processes of thought-development; + for no line of explication written by the astronomer himself on this + particular point has come down to us. There does exist, however, as we + have already stated, a very remarkable treatise by Aristarchus on the Size + and Distance of the Sun and the Moon, which so clearly suggests the + methods of reasoning of the great astronomer, and so explicitly cites the + results of his measurements, that we cannot well pass it by without + quoting from it at some length. It is certainly one of the most remarkable + scientific documents of antiquity. As already noted, the heliocentric + doctrine is not expressly stated here. It seems to be tacitly implied + throughout, but it is not a necessary consequence of any of the + propositions expressly stated. These propositions have to do with certain + observations and measurements and what Aristarchus believes to be + inevitable deductions from them, and he perhaps did not wish to have these + deductions challenged through associating them with a theory which his + contemporaries did not accept. In a word, the paper of Aristarchus is a + rigidly scientific document unvitiated by association with any theorizings + that are not directly germane to its central theme. The treatise opens + with certain hypotheses as follows: + </p> + <p> + "First. The moon receives its light from the sun. + </p> + <p> + "Second. The earth may be considered as a point and as the centre of the + orbit of the moon. + </p> + <p> + "Third. When the moon appears to us dichotomized it offers to our view a + great circle (or actual meridian) of its circumference which divides the + illuminated part from the dark part. + </p> + <p> + "Fourth. When the moon appears dichotomized its distance from the sun is + less than a quarter of the circumference (of its orbit) by a thirtieth + part of that quarter." + </p> + <p> + That is to say, in modern terminology, the moon at this time lacks three + degrees (one thirtieth of ninety degrees) of being at right angles with + the line of the sun as viewed from the earth; or, stated otherwise, the + angular distance of the moon from the sun as viewed from the earth is at + this time eighty-seven degrees—this being, as we have already + observed, the fundamental measurement upon which so much depends. We may + fairly suppose that some previous paper of Aristarchus's has detailed the + measurement which here is taken for granted, yet which of course could + depend solely on observation. + </p> + <p> + "Fifth. The diameter of the shadow (cast by the earth at the point where + the moon's orbit cuts that shadow when the moon is eclipsed) is double the + diameter of the moon." + </p> + <p> + Here again a knowledge of previously established measurements is taken for + granted; but, indeed, this is the case throughout the treatise. + </p> + <p> + "Sixth. The arc subtended in the sky by the moon is a fifteenth part of a + sign" of the zodiac; that is to say, since there are twenty-four, signs in + the zodiac, one-fifteenth of one twenty-fourth, or in modern terminology, + one degree of arc. This is Aristarchus's measurement of the moon to which + we have already referred when speaking of the measurements of Archimedes. + </p> + <p> + "If we admit these six hypotheses," Aristarchus continues, "it follows + that the sun is more than eighteen times more distant from the earth than + is the moon, and that it is less than twenty times more distant, and that + the diameter of the sun bears a corresponding relation to the diameter of + the moon; which is proved by the position of the moon when dichotomized. + But the ratio of the diameter of the sun to that of the earth is greater + than nineteen to three and less than forty-three to six. This is + demonstrated by the relation of the distances, by the position (of the + moon) in relation to the earth's shadow, and by the fact that the arc + subtended by the moon is a fifteenth part of a sign." + </p> + <p> + Aristarchus follows with nineteen propositions intended to elucidate his + hypotheses and to demonstrate his various contentions. These show a + singularly clear grasp of geometrical problems and an altogether correct + conception of the general relations as to size and position of the earth, + the moon, and the sun. His reasoning has to do largely with the shadow + cast by the earth and by the moon, and it presupposes a considerable + knowledge of the phenomena of eclipses. His first proposition is that "two + equal spheres may always be circumscribed in a cylinder; two unequal + spheres in a cone of which the apex is found on the side of the smaller + sphere; and a straight line joining the centres of these spheres is + perpendicular to each of the two circles made by the contact of the + surface of the cylinder or of the cone with the spheres." + </p> + <p> + It will be observed that Aristarchus has in mind here the moon, the earth, + and the sun as spheres to be circumscribed within a cone, which cone is + made tangible and measurable by the shadows cast by the non-luminous + bodies; since, continuing, he clearly states in proposition nine, that + "when the sun is totally eclipsed, an observer on the earth's surface is + at an apex of a cone comprising the moon and the sun." Various + propositions deal with other relations of the shadows which need not + detain us since they are not fundamentally important, and we may pass to + the final conclusions of Aristarchus, as reached in his propositions ten + to nineteen. + </p> + <p> + Now, since (proposition ten) "the diameter of the sun is more than + eighteen times and less than twenty times greater than that of the moon," + it follows (proposition eleven) "that the bulk of the sun is to that of + the moon in ratio, greater than 5832 to 1, and less than 8000 to 1." + </p> + <p> + "Proposition sixteen. The diameter of the sun is to the diameter of the + earth in greater proportion than nineteen to three, and less than + forty-three to six. + </p> + <p> + "Proposition seventeen. The bulk of the sun is to that of the earth in + greater proportion than 6859 to 27, and less than 79,507 to 216. + </p> + <p> + "Proposition eighteen. The diameter of the earth is to the diameter of the + moon in greater proportion than 108 to 43 and less than 60 to 19. + </p> + <p> + "Proposition nineteen. The bulk of the earth is to that of the moon in + greater proportion than 1,259,712 to 79,507 and less than 20,000 to 6859." + </p> + <p> + Such then are the more important conclusions of this very remarkable paper—a + paper which seems to have interest to the successors of Aristarchus + generation after generation, since this alone of all the writings of the + great astronomer has been preserved. How widely the exact results of the + measurements of Aristarchus, differ from the truth, we have pointed out as + we progressed. But let it be repeated that this detracts little from the + credit of the astronomer who had such clear and correct conceptions of the + relations of the heavenly bodies and who invented such correct methods of + measurement. Let it be particularly observed, however, that all the + conclusions of Aristarchus are stated in relative terms. He nowhere + attempts to estimate the precise size of the earth, of the moon, or of the + sun, or the actual distance of one of these bodies from another. The + obvious reason for this is that no data were at hand from which to make + such precise measurements. Had Aristarchus known the size of any one of + the bodies in question, he might readily, of course, have determined the + size of the others by the mere application of his relative scale; but he + had no means of determining the size of the earth, and to this extent his + system of measurements remained imperfect. Where Aristarchus halted, + however, another worker of the same period took the task in hand and by an + altogether wonderful measurement determined the size of the earth, and + thus brought the scientific theories of cosmology to their climax. This + worthy supplementor of the work of Aristarchus was Eratosthenes of + Alexandria. + </p> + <p> + ERATOSTHENES, "THE SURVEYOR OF THE WORLD" + </p> + <p> + An altogether remarkable man was this native of Cyrene, who came to + Alexandria from Athens to be the chief librarian of Ptolemy Euergetes. He + was not merely an astronomer and a geographer, but a poet and grammarian + as well. His contemporaries jestingly called him Beta the Second, because + he was said through the universality of his attainments to be "a second + Plato" in philosophy, "a second Thales" in astronomy, and so on throughout + the list. He was also called the "surveyor of the world," in recognition + of his services to geography. Hipparchus said of him, perhaps half + jestingly, that he had studied astronomy as a geographer and geography as + an astronomer. It is not quite clear whether the epigram was meant as + compliment or as criticism. Similar phrases have been turned against men + of versatile talent in every age. Be that as it may, Eratosthenes passed + into history as the father of scientific geography and of scientific + chronology; as the astronomer who first measured the obliquity of the + ecliptic; and as the inventive genius who performed the astounding feat of + measuring the size of the globe on which we live at a time when only a + relatively small portion of that globe's surface was known to civilized + man. It is no discredit to approach astronomy as a geographer and + geography as an astronomer if the results are such as these. What + Eratosthenes really did was to approach both astronomy and geography from + two seemingly divergent points of attack—namely, from the + stand-point of the geometer and also from that of the poet. Perhaps no man + in any age has brought a better combination of observing and imaginative + faculties to the aid of science. + </p> + <p> + Nearly all the discoveries of Eratosthenes are associated with + observations of the shadows cast by the sun. We have seen that, in the + study of the heavenly bodies, much depends on the measurement of angles. + Now the easiest way in which angles can be measured, when solar angles are + in question, is to pay attention, not to the sun itself, but to the shadow + that it casts. We saw that Thales made some remarkable measurements with + the aid of shadows, and we have more than once referred to the gnomon, + which is the most primitive, but which long remained the most important, + of astronomical instruments. It is believed that Eratosthenes invented an + important modification of the gnomon which was elaborated afterwards by + Hipparchus and called an armillary sphere. This consists essentially of a + small gnomon, or perpendicular post, attached to a plane representing the + earth's equator and a hemisphere in imitation of the earth's surface. With + the aid of this, the shadow cast by the sun could be very accurately + measured. It involves no new principle. Every perpendicular post or object + of any kind placed in the sunlight casts a shadow from which the angles + now in question could be roughly measured. The province of the armillary + sphere was to make these measurements extremely accurate. + </p> + <p> + With the aid of this implement, Eratosthenes carefully noted the longest + and the shortest shadows cast by the gnomon—that is to say, the + shadows cast on the days of the solstices. He found that the distance + between the tropics thus measured represented 47 degrees 42' 39" of arc. + One-half of this, or 23 degrees 5,' 19.5", represented the obliquity of + the ecliptic—that is to say, the angle by which the earth's axis + dipped from the perpendicular with reference to its orbit. This was a most + important observation, and because of its accuracy it has served modern + astronomers well for comparison in measuring the trifling change due to + our earth's slow, swinging wobble. For the earth, be it understood, like a + great top spinning through space, holds its position with relative but not + quite absolute fixity. It must not be supposed, however, that the + experiment in question was quite new with Eratosthenes. His merit consists + rather in the accuracy with which he made his observation than in the + novelty of the conception; for it is recorded that Eudoxus, a full century + earlier, had remarked the obliquity of the ecliptic. That observer had + said that the obliquity corresponded to the side of a pentadecagon, or + fifteen-sided figure, which is equivalent in modern phraseology to + twenty-four degrees of arc. But so little is known regarding the way in + which Eudoxus reached his estimate that the measurement of Eratosthenes is + usually spoken of as if it were the first effort of the kind. + </p> + <p> + Much more striking, at least in its appeal to the popular imagination, was + that other great feat which Eratosthenes performed with the aid of his + perfected gnomon—the measurement of the earth itself. When we + reflect that at this period the portion of the earth open to observation + extended only from the Straits of Gibraltar on the west to India on the + east, and from the North Sea to Upper Egypt, it certainly seems + enigmatical—at first thought almost miraculous—that an + observer should have been able to measure the entire globe. That he should + have accomplished this through observation of nothing more than a tiny bit + of Egyptian territory and a glimpse of the sun's shadow makes it seem but + the more wonderful. Yet the method of Eratosthenes, like many another + enigma, seems simple enough once it is explained. It required but the + application of a very elementary knowledge of the geometry of circles, + combined with the use of a fact or two from local geography—which + detracts nothing from the genius of the man who could reason from such + simple premises to so wonderful a conclusion. + </p> + <p> + Stated in a few words, the experiment of Eratosthenes was this. His + geographical studies had taught him that the town of Syene lay directly + south of Alexandria, or, as we should say, on the same meridian of + latitude. He had learned, further, that Syene lay directly under the + tropic, since it was reported that at noon on the day of the summer + solstice the gnomon there cast no shadow, while a deep well was illumined + to the bottom by the sun. A third item of knowledge, supplied by the + surveyors of Ptolemy, made the distance between Syene and Alexandria five + thousand stadia. These, then, were the preliminary data required by + Eratosthenes. Their significance consists in the fact that here is a + measured bit of the earth's arc five thousand stadia in length. If we + could find out what angle that bit of arc subtends, a mere matter of + multiplication would give us the size of the earth. But how determine this + all-important number? The answer came through reflection on the relations + of concentric circles. If you draw any number of circles, of whatever + size, about a given centre, a pair of radii drawn from that centre will + cut arcs of the same relative size from all the circles. One circle may be + so small that the actual arc subtended by the radii in a given case may be + but an inch in length, while another circle is so large that its + corresponding are is measured in millions of miles; but in each case the + same number of so-called degrees will represent the relation of each arc + to its circumference. Now, Eratosthenes knew, as just stated, that the + sun, when on the meridian on the day of the summer solstice, was directly + over the town of Syene. This meant that at that moment a radius of the + earth projected from Syene would point directly towards the sun. + Meanwhile, of course, the zenith would represent the projection of the + radius of the earth passing through Alexandria. All that was required, + then, was to measure, at Alexandria, the angular distance of the sun from + the zenith at noon on the day of the solstice to secure an approximate + measurement of the arc of the sun's circumference, corresponding to the + arc of the earth's surface represented by the measured distance between + Alexandria and Syene. + </p> + <p> + The reader will observe that the measurement could not be absolutely + accurate, because it is made from the surface of the earth, and not from + the earth's centre, but the size of the earth is so insignificant in + comparison with the distance of the sun that this slight discrepancy could + be disregarded. + </p> + <p> + The way in which Eratosthenes measured this angle was very simple. He + merely measured the angle of the shadow which his perpendicular gnomon at + Alexandria cast at mid-day on the day of the solstice, when, as already + noted, the sun was directly perpendicular at Syene. Now a glance at the + diagram will make it clear that the measurement of this angle of the + shadow is merely a convenient means of determining the precisely equal + opposite angle subtending an arc of an imaginary circle passing through + the sun; the are which, as already explained, corresponds with the arc of + the earth's surface represented by the distance between Alexandria and + Syene. He found this angle to represent 7 degrees 12', or one-fiftieth of + the circle. Five thousand stadia, then, represent one-fiftieth of the + earth's circumference; the entire circumference being, therefore, 250,000 + stadia. Unfortunately, we do not know which one of the various + measurements used in antiquity is represented by the stadia of + Eratosthenes. According to the researches of Lepsius, however, the stadium + in question represented 180 meters, and this would make the earth, + according to the measurement of Eratosthenes, about twenty-eight thousand + miles in circumference, an answer sufficiently exact to justify the wonder + which the experiment excited in antiquity, and the admiration with which + it has ever since been regarded. + </p> + <p> + {illustration caption = DIAGRAM TO ILLUSTRATE ERATOSTHENES' MEASUREMENT OF + THE GLOBE + </p> + <p> + FIG. 1. AF is a gnomon at Alexandria; SB a gnomon at Svene; IS and JK + represent the sun's rays. The angle actually measured by Eratosthenes is + KFA, as determined by the shadow cast by the gnomon AF. This angle is + equal to the opposite angle JFL, which measures the sun's distance from + the zenith; and which is also equal to the angle AES—to determine + the Size of which is the real object of the entire measurement. + </p> + <p> + FIG. 2 shows the form of the gnomon actually employed in antiquity. The + hemisphere KA being marked with a scale, it is obvious that in actual + practice Eratosthenes required only to set his gnomon in the sunlight at + the proper moment, and read off the answer to his problem at a glance. The + simplicity of the method makes the result seem all the more wonderful.} + </p> + <p> + Of course it is the method, and not its details or its exact results, that + excites our interest. And beyond question the method was an admirable one. + Its result, however, could not have been absolutely accurate, because, + while correct in principle, its data were defective. In point of fact + Syene did not lie precisely on the same meridian as Alexandria, neither + did it lie exactly on the tropic. Here, then, are two elements of + inaccuracy. Moreover, it is doubtful whether Eratosthenes made allowance, + as he should have done, for the semi-diameter of the sun in measuring the + angle of the shadow. But these are mere details, scarcely worthy of + mention from our present stand-point. What perhaps is deserving of more + attention is the fact that this epoch-making measurement of Eratosthenes + may not have been the first one to be made. A passage of Aristotle records + that the size of the earth was said to be 400,000 stadia. Some + commentators have thought that Aristotle merely referred to the area of + the inhabited portion of the earth and not to the circumference of the + earth itself, but his words seem doubtfully susceptible of this + interpretation; and if he meant, as his words seem to imply, that + philosophers of his day had a tolerably precise idea of the globe, we must + assume that this idea was based upon some sort of measurement. The + recorded size, 400,000 stadia, is a sufficient approximation to the truth + to suggest something more than a mere unsupported guess. Now, since + Aristotle died more than fifty years before Eratosthenes was born, his + report as to the alleged size of the earth certainly has a suggestiveness + that cannot be overlooked; but it arouses speculations without giving an + inkling as to their solution. If Eratosthenes had a precursor as an + earth-measurer, no hint or rumor has come down to us that would enable us + to guess who that precursor may have been. His personality is as deeply + enveloped in the mists of the past as are the personalities of the great + prehistoric discoverers. For the purpose of the historian, Eratosthenes + must stand as the inventor of the method with which his name is + associated, and as the first man of whom we can say with certainty that he + measured the size of the earth. Right worthily, then, had the Alexandrian + philosopher won his proud title of "surveyor of the world." + </p> + <p> + HIPPARCHUS, "THE LOVER OF TRUTH" + </p> + <p> + Eratosthenes outlived most of his great contemporaries. He saw the turning + of that first and greatest century of Alexandrian science, the third + century before our era. He died in the year 196 B.C., having, it is said, + starved himself to death to escape the miseries of blindness;—to the + measurer of shadows, life without light seemed not worth the living. + Eratosthenes left no immediate successor. A generation later, however, + another great figure appeared in the astronomical world in the person of + Hipparchus, a man who, as a technical observer, had perhaps no peer in the + ancient world: one who set so high a value upon accuracy of observation as + to earn the title of "the lover of truth." Hipparchus was born at Nicaea, + in Bithynia, in the year 160 B.C. His life, all too short for the + interests of science, ended in the year 125 B.C. The observations of the + great astronomer were made chiefly, perhaps entirely, at Rhodes. A + misinterpretation of Ptolemy's writings led to the idea that Hipparchus, + performed his chief labors in Alexandria, but it is now admitted that + there is no evidence for this. Delambre doubted, and most subsequent + writers follow him here, whether Hipparchus ever so much as visited + Alexandria. In any event there seems to be no question that Rhodes may + claim the honor of being the chief site of his activities. + </p> + <p> + It was Hipparchus whose somewhat equivocal comment on the work of + Eratosthenes we have already noted. No counter-charge in kind could be + made against the critic himself; he was an astronomer pure and simple. His + gift was the gift of accurate observation rather than the gift of + imagination. No scientific progress is possible without scientific + guessing, but Hipparchus belonged to that class of observers with whom + hypothesis is held rigidly subservient to fact. It was not to be expected + that his mind would be attracted by the heliocentric theory of + Aristarchus. He used the facts and observations gathered by his great + predecessor of Samos, but he declined to accept his theories. For him the + world was central; his problem was to explain, if he could, the + irregularities of motion which sun, moon, and planets showed in their + seeming circuits about the earth. Hipparchus had the gnomon of + Eratosthenes—doubtless in a perfected form—to aid him, and he + soon proved himself a master in its use. For him, as we have said, + accuracy was everything; this was the one element that led to all his + great successes. + </p> + <p> + Perhaps his greatest feat was to demonstrate the eccentricity of the sun's + seeming orbit. We of to-day, thanks to Keppler and his followers, know + that the earth and the other planetary bodies in their circuit about the + sun describe an ellipse and not a circle. But in the day of Hipparchus, + though the ellipse was recognized as a geometrical figure (it had been + described and named along with the parabola and hyperbola by Apollonius of + Perga, the pupil of Euclid), yet it would have been the rankest heresy to + suggest an elliptical course for any heavenly body. A metaphysical theory, + as propounded perhaps by the Pythagoreans but ardently supported by + Aristotle, declared that the circle is the perfect figure, and pronounced + it inconceivable that the motions of the spheres should be other than + circular. This thought dominated the mind of Hipparchus, and so when his + careful measurements led him to the discovery that the northward and + southward journeyings of the sun did not divide the year into four equal + parts, there was nothing open to him but to either assume that the earth + does not lie precisely at the centre of the sun's circular orbit or to + find some alternative hypothesis. + </p> + <p> + In point of fact, the sun (reversing the point of view in accordance with + modern discoveries) does lie at one focus of the earth's elliptical orbit, + and therefore away from the physical centre of that orbit; in other words, + the observations of Hipparchus were absolutely accurate. He was quite + correct in finding that the sun spends more time on one side of the + equator than on the other. When, therefore, he estimated the relative + distance of the earth from the geometrical centre of the sun's supposed + circular orbit, and spoke of this as the measure of the sun's + eccentricity, he propounded a theory in which true data of observation + were curiously mingled with a positively inverted theory. That the theory + of Hipparchus was absolutely consistent with all the facts of this + particular observation is the best evidence that could be given of the + difficulties that stood in the way of a true explanation of the mechanism + of the heavens. + </p> + <p> + But it is not merely the sun which was observed to vary in the speed of + its orbital progress; the moon and the planets also show curious + accelerations and retardations of motion. The moon in particular received + most careful attention from Hipparchus. Dominated by his conception of the + perfect spheres, he could find but one explanation of the anomalous + motions which he observed, and this was to assume that the various + heavenly bodies do not fly on in an unvarying arc in their circuit about + the earth, but describe minor circles as they go which can be likened to + nothing so tangibly as to a light attached to the rim of a wagon-wheel in + motion. If such an invisible wheel be imagined as carrying the sun, for + example, on its rim, while its invisible hub follows unswervingly the + circle of the sun's mean orbit (this wheel, be it understood, lying in the + plane of the orbit, not at right-angles to it), then it must be obvious + that while the hub remains always at the same distance from the earth, the + circling rim will carry the sun nearer the earth, then farther away, and + that while it is traversing that portion of the are which brings it + towards the earth, the actual forward progress of the sun will be retarded + notwithstanding the uniform motion of the hub, just as it will be + accelerated in the opposite arc. Now, if we suppose our sun-bearing wheel + to turn so slowly that the sun revolves but once about its imaginary hub + while the wheel itself is making the entire circuit of the orbit, we shall + have accounted for the observed fact that the sun passes more quickly + through one-half of the orbit than through the other. Moreover, if we can + visualize the process and imagine the sun to have left a visible line of + fire behind him throughout the course, we shall see that in reality the + two circular motions involved have really resulted in producing an + elliptical orbit. + </p> + <p> + The idea is perhaps made clearer if we picture the actual progress of the + lantern attached to the rim of an ordinary cart-wheel. When the cart is + drawn forward the lantern is made to revolve in a circle as regards the + hub of the wheel, but since that hub is constantly going forward, the + actual path described by the lantern is not a circle at all but a waving + line. It is precisely the same with the imagined course of the sun in its + orbit, only that we view these lines just as we should view the lantern on + the wheel if we looked at it from directly above and not from the side. + The proof that the sun is describing this waving line, and therefore must + be considered as attached to an imaginary wheel, is furnished, as it + seemed to Hipparchus, by the observed fact of the sun's varying speed. + </p> + <p> + That is one way of looking at the matter. It is an hypothesis that + explains the observed facts—after a fashion, and indeed a very + remarkable fashion. The idea of such an explanation did not originate with + Hipparchus. The germs of the thought were as old as the Pythagorean + doctrine that the earth revolves about a centre that we cannot see. + Eudoxus gave the conception greater tangibility, and may be considered as + the father of this doctrine of wheels—epicycles, as they came to be + called. Two centuries before the time of Hipparchus he conceived a + doctrine of spheres which Aristotle found most interesting, and which + served to explain, along the lines we have just followed, the observed + motions of the heavenly bodies. Calippus, the reformer of the calendar, is + said to have carried an account of this theory to Aristotle. As new + irregularities of motion of the sun, moon, and planetary bodies were + pointed out, new epicycles were invented. There is no limit to the number + of imaginary circles that may be inscribed about an imaginary centre, and + if we conceive each one of these circles to have a proper motion of its + own, and each one to carry the sun in the line of that motion, except as + it is diverted by the other motions—if we can visualize this complex + mingling of wheels—we shall certainly be able to imagine the + heavenly body which lies at the juncture of all the rims, as being carried + forward in as erratic and wobbly a manner as could be desired. In other + words, the theory of epicycles will account for all the facts of the + observed motions of all the heavenly bodies, but in so doing it fills the + universe with a most bewildering network of intersecting circles. Even in + the time of Calippus fifty-five of these spheres were computed. + </p> + <p> + We may well believe that the clear-seeing Aristarchus would look askance + at such a complex system of imaginary machinery. But Hipparchus, + pre-eminently an observer rather than a theorizer, seems to have been + content to accept the theory of epicycles as he found it, though his + studies added to its complexities; and Hipparchus was the dominant + scientific personality of his century. What he believed became as a law to + his immediate successors. His tenets were accepted as final by their great + popularizer, Ptolemy, three centuries later; and so the heliocentric + theory of Aristarchus passed under a cloud almost at the hour of its + dawning, there to remain obscured and forgotten for the long lapse of + centuries. A thousand pities that the greatest observing astronomer of + antiquity could not, like one of his great precursors, have approached + astronomy from the stand-point of geography and poetry. Had he done so, + perhaps he might have reflected, like Aristarchus before him, that it + seems absurd for our earth to hold the giant sun in thraldom; then perhaps + his imagination would have reached out to the heliocentric doctrine, and + the cobweb hypothesis of epicycles, with that yet more intangible figment + of the perfect circle, might have been wiped away. + </p> + <p> + But it was not to be. With Aristarchus the scientific imagination had + reached its highest flight; but with Hipparchus it was beginning to settle + back into regions of foggier atmosphere and narrower horizons. For what, + after all, does it matter that Hipparchus should go on to measure the + precise length of the year and the apparent size of the moon's disk; that + he should make a chart of the heavens showing the place of 1080 stars; + even that he should discover the precession of the equinox;—what, + after all, is the significance of these details as against the + all-essential fact that the greatest scientific authority of his century—the + one truly heroic scientific figure of his epoch—should have lent all + the forces of his commanding influence to the old, false theory of + cosmology, when the true theory had been propounded and when he, perhaps, + was the only man in the world who might have substantiated and vitalized + that theory? It is easy to overestimate the influence of any single man, + and, contrariwise, to underestimate the power of the Zeitgeist. But when + we reflect that the doctrines of Hipparchus, as promulgated by Ptolemy, + became, as it were, the last word of astronomical science for both the + Eastern and Western worlds, and so continued after a thousand years, it is + perhaps not too much to say that Hipparchus, "the lover of truth," missed + one of the greatest opportunities for the promulgation of truth ever + vouchsafed to a devotee of pure science. + </p> + <p> + But all this, of course, detracts nothing from the merits of Hipparchus as + an observing astronomer. A few words more must be said as to his specific + discoveries in this field. According to his measurement, the tropic year + consists of 365 days, 5 hours, and 49 minutes, varying thus only 12 + seconds from the true year, as the modern astronomer estimates it. Yet + more remarkable, because of the greater difficulties involved, was + Hipparchus's attempt to measure the actual distance of the moon. + Aristarchus had made a similar attempt before him. Hipparchus based his + computations on studies of the moon in eclipse, and he reached the + conclusion that the distance of the moon is equal to 59 radii of the earth + (in reality it is 60.27 radii). Here, then, was the measure of the + base-line of that famous triangle with which Aristarchus had measured the + distance of the sun. Hipparchus must have known of that measurement, since + he quotes the work of Aristarchus in other fields. Had he now but repeated + the experiment of Aristarchus, with his perfected instruments and his + perhaps greater observational skill, he was in position to compute the + actual distance of the sun in terms not merely of the moon's distance but + of the earth's radius. And now there was the experiment of Eratosthenes to + give the length of that radius in precise terms. In other words, + Hipparchus might have measured the distance of the sun in stadia. But if + he had made the attempt—and, indeed, it is more than likely that he + did so—the elements of error in his measurements would still have + kept him wide of the true figures. + </p> + <p> + The chief studies of Hipparchus were directed, as we have seen, towards + the sun and the moon, but a phenomenon that occurred in the year 134 B.C. + led him for a time to give more particular attention to the fixed stars. + The phenomenon in question was the sudden outburst of a new star; a + phenomenon which has been repeated now and again, but which is + sufficiently rare and sufficiently mysterious to have excited the unusual + attention of astronomers in all generations. Modern science offers an + explanation of the phenomenon, as we shall see in due course. We do not + know that Hipparchus attempted to explain it, but he was led to make a + chart of the heavens, probably with the idea of guiding future observers + in the observation of new stars. Here again Hipparchus was not altogether + an innovator, since a chart showing the brightest stars had been made by + Eratosthenes; but the new charts were much elaborated. + </p> + <p> + The studies of Hipparchus led him to observe the stars chiefly with + reference to the meridian rather than with reference to their rising, as + had hitherto been the custom. In making these studies of the relative + position of the stars, Hipparchus was led to compare his observations with + those of the Babylonians, which, it was said, Alexander had caused to be + transmitted to Greece. He made use also of the observations of Aristarchus + and others of his Greek precursors. The result of his comparisons proved + that the sphere of the fixed stars had apparently shifted its position in + reference to the plane of the sun's orbit—that is to say, the plane + of the ecliptic no longer seemed to cut the sphere of the fixed stars at + precisely the point where the two coincided in former centuries. The plane + of the ecliptic must therefore be conceived as slowly revolving in such a + way as gradually to circumnavigate the heavens. This important phenomenon + is described as the precession of the equinoxes. + </p> + <p> + It is much in question whether this phenomenon was not known to the + ancient Egyptian astronomers; but in any event, Hipparchus is to be + credited with demonstrating the fact and making it known to the Western + world. A further service was rendered theoretical astronomy by Hipparchus + through his invention of the planosphere, an instrument for the + representation of the mechanism of the heavens. His computations of the + properties of the spheres led him also to what was virtually a discovery + of the method of trigonometry, giving him, therefore, a high position in + the field of mathematics. All in all, then, Hipparchus is a most heroic + figure. He may well be considered the greatest star-gazer of antiquity, + though he cannot, without injustice to his great precursors, be allowed + the title which is sometimes given him of "father of systematic + astronomy." + </p> + <p> + CTESIBIUS AND HERO: MAGICIANS OF ALEXANDRIA + </p> + <p> + Just about the time when Hipparchus was working out at Rhodes his puzzles + of celestial mechanics, there was a man in Alexandria who was exercising a + strangely inventive genius over mechanical problems of another sort; a man + who, following the example set by Archimedes a century before, was + studying the problems of matter and putting his studies to practical + application through the invention of weird devices. The man's name was + Ctesibius. We know scarcely more of him than that he lived in Alexandria, + probably in the first half of the second century B.C. His antecedents, the + place and exact time of his birth and death, are quite unknown. Neither + are we quite certain as to the precise range of his studies or the exact + number of his discoveries. It appears that he had a pupil named Hero, + whose personality, unfortunately, is scarcely less obscure than that of + his master, but who wrote a book through which the record of the master's + inventions was preserved to posterity. Hero, indeed, wrote several books, + though only one of them has been preserved. The ones that are lost bear + the following suggestive titles: On the Construction of Slings; On the + Construction of Missiles; On the Automaton; On the Method of Lifting Heavy + Bodies; On the Dioptric or Spying-tube. The work that remains is called + Pneumatics, and so interesting a work it is as to make us doubly regret + the loss of its companion volumes. Had these other books been preserved we + should doubtless have a clearer insight than is now possible into some at + least of the mechanical problems that exercised the minds of the ancient + philosophers. The book that remains is chiefly concerned, as its name + implies, with the study of gases, or, rather, with the study of a single + gas, this being, of course, the air. But it tells us also of certain + studies in the dynamics of water that are most interesting, and for the + historian of science most important. + </p> + <p> + Unfortunately, the pupil of Ctesibius, whatever his ingenuity, was a man + with a deficient sense of the ethics of science. He tells us in his + preface that the object of his book is to record some ingenious + discoveries of others, together with additional discoveries of his own, + but nowhere in the book itself does he give us the, slightest clew as to + where the line is drawn between the old and the new. Once, in discussing + the weight of water, he mentions the law of Archimedes regarding a + floating body, but this is the only case in which a scientific principle + is traced to its source or in which credit is given to any one for a + discovery. This is the more to be regretted because Hero has discussed at + some length the theories involved in the treatment of his subject. This + reticence on the part of Hero, combined with the fact that such somewhat + later writers as Pliny and Vitruvius do not mention Hero's name, while + they frequently mention the name of his master, Ctesibius, has led modern + critics to a somewhat sceptical attitude regarding the position of Hero as + an actual discoverer. + </p> + <p> + The man who would coolly appropriate some discoveries of others under + cloak of a mere prefatorial reference was perhaps an expounder rather than + an innovator, and had, it is shrewdly suspected, not much of his own to + offer. Meanwhile, it is tolerably certain that Ctesibius was the + discoverer of the principle of the siphon, of the forcing-pump, and of a + pneumatic organ. An examination of Hero's book will show that these are + really the chief principles involved in most of the various interesting + mechanisms which he describes. We are constrained, then, to believe that + the inventive genius who was really responsible for the mechanisms we are + about to describe was Ctesibius, the master. Yet we owe a debt of + gratitude to Hero, the pupil, for having given wider vogue to these + discoveries, and in particular for the discussion of the principles of + hydrostatics and pneumatics contained in the introduction to his book. + This discussion furnishes us almost our only knowledge as to the progress + of Greek philosophers in the field of mechanics since the time of + Archimedes. + </p> + <p> + The main purpose of Hero in his preliminary thesis has to do with the + nature of matter, and recalls, therefore, the studies of Anaxagoras and + Democritus. Hero, however, approaches his subject from a purely material + or practical stand-point. He is an explicit champion of what we nowadays + call the molecular theory of matter. "Every body," he tells us, "is + composed of minute particles, between which are empty spaces less than + these particles of the body. It is, therefore, erroneous to say that there + is no vacuum except by the application of force, and that every space is + full either of air or water or some other substance. But in proportion as + any one of these particles recedes, some other follows it and fills the + vacant space; therefore there is no continuous vacuum, except by the + application of some force (like suction)—that is to say, an absolute + vacuum is never found, except as it is produced artificially." Hero brings + forward some thoroughly convincing proofs of the thesis he is maintaining. + "If there were no void places between the particles of water," he says, + "the rays of light could not penetrate the water; moreover, another + liquid, such as wine, could not spread itself through the water, as it is + observed to do, were the particles of water absolutely continuous." The + latter illustration is one the validity of which appeals as forcibly to + the physicists of to-day as it did to Hero. The same is true of the + argument drawn from the compressibility of gases. Hero has evidently made + a careful study of this subject. He knows that an inverted tube full of + air may be immersed in water without becoming wet on the inside, proving + that air is a physical substance; but he knows also that this same air may + be caused to expand to a much greater bulk by the application of heat, or + may, on the other hand, be condensed by pressure, in which case, as he is + well aware, the air exerts force in the attempt to regain its normal bulk. + But, he argues, surely we are not to believe that the particles of air + expand to fill all the space when the bulk of air as a whole expands under + the influence of heat; nor can we conceive that the particles of normal + air are in actual contact, else we should not be able to compress the air. + Hence his conclusion, which, as we have seen, he makes general in its + application to all matter, that there are spaces, or, as he calls them, + vacua, between the particles that go to make up all substances, whether + liquid, solid, or gaseous. + </p> + <p> + Here, clearly enough, was the idea of the "atomic" nature of matter + accepted as a fundamental notion. The argumentative attitude assumed by + Hero shows that the doctrine could not be expected to go unchallenged. + But, on the other hand, there is nothing in his phrasing to suggest an + intention to claim originality for any phase of the doctrine. We may infer + that in the three hundred years that had elapsed since the time of + Anaxagoras, that philosopher's idea of the molecular nature of matter had + gained fairly wide currency. As to the expansive power of gas, which Hero + describes at some length without giving us a clew to his authorities, we + may assume that Ctesibius was an original worker, yet the general facts + involved were doubtless much older than his day. Hero, for example, tells + us of the cupping-glass used by physicians, which he says is made into a + vacuum by burning up the air in it; but this apparatus had probably been + long in use, and Hero mentions it not in order to describe the ordinary + cupping-glass which is referred to, but a modification of it. He refers to + the old form as if it were something familiar to all. + </p> + <p> + Again, we know that Empedocles studied the pressure of the air in the + fifth century B.C., and discovered that it would support a column of water + in a closed tube, so this phase of the subject is not new. But there is no + hint anywhere before this work of Hero of a clear understanding that the + expansive properties of the air when compressed, or when heated, may be + made available as a motor power. Hero, however, has the clearest notions + on the subject and puts them to the practical test of experiment. Thus he + constructs numerous mechanisms in which the expansive power of air under + pressure is made to do work, and others in which the same end is + accomplished through the expansive power of heated air. For example, the + doors of a temple are made to swing open automatically when a fire is + lighted on a distant altar, closing again when the fire dies out—effects + which must have filled the minds of the pious observers with bewilderment + and wonder, serving a most useful purpose for the priests, who alone, we + may assume, were in the secret. There were two methods by which this + apparatus was worked. In one the heated air pressed on the water in a + close retort connected with the altar, forcing water out of the retort + into a bucket, which by its weight applied a force through pulleys and + ropes that turned the standards on which the temple doors revolved. When + the fire died down the air contracted, the water was siphoned back from + the bucket, which, being thus lightened, let the doors close again through + the action of an ordinary weight. The other method was a slight + modification, in which the retort of water was dispensed with and a + leather sack like a large football substitued. The ropes and pulleys were + connected with this sack, which exerted a pull when the hot air expanded, + and which collapsed and thus relaxed its strain when the air cooled. A + glance at the illustrations taken from Hero's book will make the details + clear. + </p> + <p> + Other mechanisms utilized a somewhat different combination of weights, + pulleys, and siphons, operated by the expansive power of air, unheated but + under pressure, such pressure being applied with a force-pump, or by the + weight of water running into a closed receptacle. One such mechanism gives + us a constant jet of water or perpetual fountain. Another curious + application of the principle furnishes us with an elaborate toy, + consisting of a group of birds which alternately whistle or are silent, + while an owl seated on a neighboring perch turns towards the birds when + their song begins and away from them when it ends. The "singing" of the + birds, it must be explained, is produced by the expulsion of air through + tiny tubes passing up through their throats from a tank below. The owl is + made to turn by a mechanism similar to that which manipulates the temple + doors. The pressure is supplied merely by a stream of running water, and + the periodical silence of the birds is due to the fact that this pressure + is relieved through the automatic siphoning off of the water when it + reaches a certain height. The action of the siphon, it may be added, is + correctly explained by Hero as due to the greater weight of the water in + the longer arm of the bent tube. As before mentioned, the siphon is + repeatedly used in these mechanisms of Hero. The diagram will make clear + the exact application of it in the present most ingenious mechanism. We + may add that the principle of the whistle was a favorite one of Hero. By + the aid of a similar mechanism he brought about the blowing of trumpets + when the temple doors were opened, a phenomenon which must greatly have + enhanced the mystification. It is possible that this principle was + utilized also in connection with statues to produce seemingly supernatural + effects. This may be the explanation of the tradition of the speaking + statue in the temple of Ammon at Thebes. + </p> + <p> + {illustration caption = DEVICE FOR CAUSING THE DOORS OF THE TEMPLE TO OPEN + WHEN THE FIRE ON THE ALTAR IS LIGHTED (Air heated in the altar F drives + water from the closed receptacle H through the tube KL into the bucket M, + which descends through gravity, thus opening the doors. When the altar + cools, the air contracts, the water is sucked from the bucket, and the + weight and pulley close the doors.)} + </p> + <p> + {illustration caption = THE STEAM-ENGINE OF HERO (The steam generated in + the receptacle AB passes through the tube EF into the globe, and escapes + through the bent tubes H and K, causing the globe to rotate on the axis + LG.)} + </p> + <p> + The utilization of the properties of compressed air was not confined, + however, exclusively to mere toys, or to produce miraculous effects. The + same principle was applied to a practical fire-engine, worked by levers + and force-pumps; an apparatus, in short, altogether similar to that still + in use in rural districts. A slightly different application of the motive + power of expanding air is furnished in a very curious toy called "the + dancing figures." In this, air heated in a retort like a miniature altar + is allowed to escape through the sides of two pairs of revolving arms + precisely like those of the ordinary revolving fountain with which we are + accustomed to water our lawns, the revolving arms being attached to a + plane on which several pairs of statuettes representing dancers are + placed, An even more interesting application of this principle of setting + a wheel in motion is furnished in a mechanism which must be considered the + earliest of steam-engines. Here, as the name implies, the gas supplying + the motive power is actually steam. The apparatus made to revolve is a + globe connected with the steam-retort by a tube which serves as one of its + axes, the steam escaping from the globe through two bent tubes placed at + either end of an equatorial diameter. It does not appear that Hero had any + thought of making practical use of this steam-engine. It was merely a + curious toy—nothing more. Yet had not the age that succeeded that of + Hero been one in which inventive genius was dormant, some one must soon + have hit upon the idea that this steam-engine might be improved and made + to serve a useful purpose. As the case stands, however, there was no + advance made upon the steam motor of Hero for almost two thousand years. + And, indeed, when the practical application of steam was made, towards the + close of the eighteenth century, it was made probably quite without + reference to the experiment of Hero, though knowledge of his toy may + perhaps have given a clew to Watt or his predecessors. + </p> + <p> + {illustration caption = THE SLOT-MACHINE OF HERO (The coin introduced at A + falls on the lever R, and by its weight opens the valve S, permitting the + liquid to escape through the invisible tube LM. As the lever tips, the + coin slides off and the valve closes. The liquid in tank must of course be + kept above F.)} + </p> + <p> + In recent times there has been a tendency to give to this steam-engine of + Hero something more than full meed of appreciation. To be sure, it marked + a most important principle in the conception that steam might be used as a + motive power, but, except in the demonstration of this principle, the + mechanism of Hero was much too primitive to be of any importance. But + there is one mechanism described by Hero which was a most explicit + anticipation of a device, which presumably soon went out of use, and which + was not reinvented until towards the close of the nineteenth century. This + was a device which has become familiar in recent times as the + penny-in-the-slot machine. When towards the close of the nineteenth + century some inventive craftsman hit upon the idea of an automatic machine + to supply candy, a box of cigarettes, or a whiff of perfumery, he may or + may not have borrowed his idea from the slot-machine of Hero; but in any + event, instead of being an innovator he was really two thousand years + behind the times, for the slot-machine of Hero is the precise prototype of + these modern ones. + </p> + <p> + The particular function which the mechanism of Hero was destined to fulfil + was the distribution of a jet of water, presumably used for sacramental + purposes, which was given out automatically when a five-drachma coin was + dropped into the slot at the top of the machine. The internal mechanism of + the machine was simple enough, consisting merely of a lever operating a + valve which was opened by the weight of the coin dropping on the little + shelf at the end of the lever, and which closed again when the coin slid + off the shelf. The illustration will show how simple this mechanism was. + Yet to the worshippers, who probably had entered the temple through doors + miraculously opened, and who now witnessed this seemingly intelligent + response of a machine, the result must have seemed mystifying enough; and, + indeed, for us also, when we consider how relatively crude was the + mechanical knowledge of the time, this must seem nothing less than + marvellous. As in imagination we walk up to the sacred tank, drop our + drachma in the slot, and hold our hand for the spurt of holy-water, can we + realize that this is the land of the Pharaohs, not England or America; + that the kingdom of the Ptolemies is still at its height; that the + republic of Rome is mistress of the world; that all Europe north of the + Alps is inhabited solely by barbarians; that Cleopatra and Julius Caesar + are yet unborn; that the Christian era has not yet begun? Truly, it seems + as if there could be no new thing under the sun. + </p> + <p> + <a name="link2H_4_0012" id="link2H_4_0012"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + X. SCIENCE OF THE ROMAN PERIOD + </h2> + <p> + We have seen that the third century B.C. was a time when Alexandrian + science was at its height, but that the second century produced also in + Hipparchus at least one investigator of the very first rank; though, to be + sure, Hipparchus can be called an Alexandrian only by courtesy. In the + ensuing generations the Greek capital at the mouth of the Nile continued + to hold its place as the centre of scientific and philosophical thought. + The kingdom of the Ptolemies still flourished with at least the outward + appearances of its old-time glory, and a company of grammarians and + commentators of no small merit could always be found in the service of the + famous museum and library; but the whole aspect of world-history was + rapidly changing. Greece, after her brief day of political supremacy, was + sinking rapidly into desuetude, and the hard-headed Roman in the West was + making himself master everywhere. While Hipparchus of Rhodes was in his + prime, Corinth, the last stronghold of the main-land of Greece, had fallen + before the prowess of the Roman, and the kingdom of the Ptolemies, though + still nominally free, had begun to come within the sphere of Roman + influence. + </p> + <p> + Just what share these political changes had in changing the aspect of + Greek thought is a question regarding which difference of opinion might + easily prevail; but there can be no question that, for one reason or + another, the Alexandrian school as a creative centre went into a rapid + decline at about the time of the Roman rise to world-power. There are some + distinguished names, but, as a general rule, the spirit of the times is + reminiscent rather than creative; the workers tend to collate the + researches of their predecessors rather than to make new and original + researches for themselves. Eratosthenes, the inventive world-measurer, was + succeeded by Strabo, the industrious collator of facts; Aristarchus and + Hipparchus, the originators of new astronomical methods, were succeeded by + Ptolemy, the perfecter of their methods and the systematizer of their + knowledge. Meanwhile, in the West, Rome never became a true + culture-centre. The great genius of the Roman was political; the Augustan + Age produced a few great historians and poets, but not a single great + philosopher or creative devotee of science. Cicero, Lucian, Seneca, Marcus + Aurelius, give us at best a reflection of Greek philosophy. Pliny, the one + world-famous name in the scientific annals of Rome, can lay claim to no + higher credit than that of a marvellously industrious collector of facts—the + compiler of an encyclopaedia which contains not one creative touch. + </p> + <p> + All in all, then, this epoch of Roman domination is one that need detain + the historian of science but a brief moment. With the culmination of Greek + effort in the so-called Hellenistic period we have seen ancient science at + its climax. The Roman period is but a time of transition, marking, as it + were, a plateau on the slope between those earlier heights and the deep, + dark valleys of the Middle Ages. Yet we cannot quite disregard the efforts + of such workers as those we have just named. Let us take a more specific + glance at their accomplishments. + </p> + <p> + STRABO THE GEOGRAPHER + </p> + <p> + The earliest of these workers in point of time is Strabo. This most famous + of ancient geographers was born in Amasia, Pontus, about 63 B.C., and + lived to the year 24 A.D., living, therefore, in the age of Caesar and + Augustus, during which the final transformation in the political position + of the kingdom of Egypt was effected. The name of Strabo in a modified + form has become popularized through a curious circumstance. The + geographer, it appears, was afflicted with a peculiar squint of the eyes, + hence the name strabismus, which the modern oculist applies to that + particular infirmity. + </p> + <p> + Fortunately, the great geographer has not been forced to depend upon + hearsay evidence for recognition. His comprehensive work on geography has + been preserved in its entirety, being one of the few expansive classical + writings of which this is true. The other writings of Strabo, however, + including certain histories of which reports have come down to us, are + entirely lost. The geography is in many ways a remarkable book. It is not, + however, a work in which any important new principles are involved. Rather + is it typical of its age in that it is an elaborate compilation and a + critical review of the labors of Strabo's predecessors. Doubtless it + contains a vast deal of new information as to the details of geography—precise + areas and distance, questions of geographical locations as to latitude and + zones, and the like. But however important these details may have been + from a contemporary stand-point, they, of course, can have nothing more + than historical interest to posterity. The value of the work from our + present stand-point is chiefly due to the criticisms which Strabo passes + upon his forerunners, and to the incidental historical and scientific + references with which his work abounds. Being written in this closing + period of ancient progress, and summarizing, as it does, in full detail + the geographical knowledge of the time, it serves as an important + guide-mark for the student of the progress of scientific thought. We + cannot do better than briefly to follow Strabo in his estimates and + criticisms of the work of his predecessors, taking note thus of the point + of view from which he himself looked out upon the world. We shall thus + gain a clear idea as to the state of scientific geography towards the + close of the classical epoch. + </p> + <p> + "If the scientific investigation of any subject be the proper avocation of + the philosopher," says Strabo, "geography, the science of which we propose + to treat, is certainly entitled to a high place; and this is evident from + many considerations. They who first undertook to handle the matter were + distinguished men. Homer, Anaximander the Milesian, and Hecaeus (his + fellow-citizen according to Eratosthenes), Democritus, Eudoxus, + Dicaearchus, and Ephorus, with many others, and after these, Eratosthenes, + Polybius, and Posidonius, all of them philosophers. Nor is the great + learning through which alone this subject can be approached possessed by + any but a person acquainted with both human and divine things, and these + attainments constitute what is called philosophy. In addition to its vast + importance in regard to social life and the art of government, geography + unfolds to us a celestial phenomena, acquaints us with the occupants of + the land and ocean, and the vegetation, fruits, and peculiarities of the + various quarters of the earth, a knowledge of which marks him who + cultivates it as a man earnest in the great problem of life and + happiness." + </p> + <p> + Strabo goes on to say that in common with other critics, including + Hipparchus, he regards Homer as the first great geographer. He has much to + say on the geographical knowledge of the bard, but this need not detain + us. We are chiefly concerned with his comment upon his more recent + predecessors, beginning with Eratosthenes. The constant reference to this + worker shows the important position which he held. Strabo appears neither + as detractor nor as partisan, but as one who earnestly desires the truth. + Sometimes he seems captious in his criticisms regarding some detail, nor + is he always correct in his emendations of the labors of others; but, on + the whole, his work is marked by an evident attempt at fairness. In + reading his book, however, one is forced to the conclusion that Strabo is + an investigator of details, not an original thinker. He seems more + concerned with precise measurements than with questionings as to the open + problems of his science. Whatever he accepts, then, may be taken as + virtually the stock doctrine of the period. + </p> + <p> + "As the size of the earth," he says, "has been demonstrated by other + writers, we shall here take for granted and receive as accurate what they + have advanced. We shall also assume that the earth is spheroidal, that its + surface is likewise spheroidal and, above all, that bodies have a tendency + towards its centre, which latter point is clear to the perception of the + most average understanding. However, we may show summarily that the earth + is spheroidal, from the consideration that all things, however distant, + tend to its centre, and that every body is attracted towards its centre by + gravity. This is more distinctly proved from observations of the sea and + sky, for here the evidence of the senses and common observation is alone + requisite. The convexity of the sea is a further proof of this to those + who have sailed, for they cannot perceive lights at a distance when placed + at the same level as their eyes, and if raised on high they at once become + perceptible to vision though at the same time farther removed. So when the + eye is raised it sees what before was utterly imperceptible. Homer speaks + of this when he says: + </p> +<pre xml:space="preserve"> + "'Lifted up on the vast wave he quickly beheld afar.' +</pre> + <p> + "Sailors as they approach their destination behold the shore continually + raising itself to their view, and objects which had at first seemed low + begin to lift themselves. Our gnomons, also, are, among other things, + evidence of the revolution of the heavenly bodies, and common-sense at + once shows us that if the depth of the earth were infinite such a + revolution could not take place."(1) + </p> + <p> + Elsewhere Strabo criticises Eratosthenes for having entered into a long + discussion as to the form of the earth. This matter, Strabo thinks, + "should have been disposed of in the compass of a few words." Obviously + this doctrine of the globe's sphericity had, in the course of 600 years, + become so firmly established among the Greek thinkers as to seem almost + axiomatic. We shall see later on how the Western world made a curious + recession from this seemingly secure position under stimulus of an + Oriental misconception. As to the size of the globe, Strabo is disposed to + accept without particular comment the measurements of Eratosthenes. He + speaks, however, of "more recent measurements," referring in particular to + that adopted by Posidonius, according to which the circumference is only + about one hundred and eighty thousand stadia. Posidonius, we may note in + passing, was a contemporary and friend of Cicero, and hence lived shortly + before the time of Strabo. His measurement of the earth was based on + observations of a star which barely rose above the southern horizon at + Rhodes as compared with the height of the same star when observed at + Alexandria. This measurement of Posidonius, together with the even more + famous measurement of Eratosthenes, appears to have been practically the + sole guide as to the size of the earth throughout the later periods of + antiquity, and, indeed, until the later Middle Ages. + </p> + <p> + As becomes a writer who is primarily geographer and historian rather than + astronomer, Strabo shows a much keener interest in the habitable portions + of the globe than in the globe as a whole. He assures us that this + habitable portion of the earth is a great island, "since wherever men have + approached the termination of the land, the sea, which we designate ocean, + has been met with, and reason assures us of the similarity of this place + which our senses have not been tempted to survey." He points out that + whereas sailors have not circumnavigated the globe, that they had not been + prevented from doing so by any continent, and it seems to him altogether + unlikely that the Atlantic Ocean is divided into two seas by narrow + isthmuses so placed as to prevent circumnavigation. "How much more + probable that it is confluent and uninterrupted. This theory," he adds, + "goes better with the ebb and flow of the ocean. Moreover (and here his + reasoning becomes more fanciful), the greater the amount of moisture + surrounding the earth, the easier would the heavenly bodies be supplied + with vapor from thence." Yet he is disposed to believe, following Plato, + that the tradition "concerning the island of Atlantos might be received as + something more than idle fiction, it having been related by Solon, on the + authority of the Egyptian priests, that this island, almost as large as a + continent, was formerly in existence although now it had disappeared."(2) + </p> + <p> + In a word, then, Strabo entertains no doubt whatever that it would be + possible to sail around the globe from Spain to India. Indeed, so + matter-of-fact an inference was this that the feat of Columbus would have + seemed less surprising in the first century of our era than it did when + actually performed in the fifteenth century. The terrors of the great + ocean held the mariner back, rather than any doubt as to where he would + arrive at the end of the voyage. + </p> + <p> + Coupled with the idea that the habitable portion of the earth is an + island, there was linked a tolerably definite notion as to the shape of + this island. This shape Strabo likens to a military cloak. The comparison + does not seem peculiarly apt when we are told presently that the length of + the habitable earth is more than twice its breadth. This idea, Strabo + assures us, accords with the most accurate observations "both ancient and + modern." These observations seemed to show that it is not possible to live + in the region close to the equator, and that, on the other hand, the cold + temperature sharply limits the habitability of the globe towards the + north. All the civilization of antiquity clustered about the + Mediterranean, or extended off towards the east at about the same + latitude. Hence geographers came to think of the habitable globe as having + the somewhat lenticular shape which a crude map of these regions suggests. + We have already had occasion to see that at an earlier day Anaxagoras was + perhaps influenced in his conception of the shape of the earth by this + idea, and the constant references of Strabo impress upon us the thought + that this long, relatively narrow area of the earth's surface is the only + one which can be conceived of as habitable. + </p> + <p> + Strabo had much to tell us concerning zones, which, following Posidonius, + he believes to have been first described by Parmenides. We may note, + however, that other traditions assert that both Thales and Pythagoras had + divided the earth into zones. The number of zones accepted by Strabo is + five, and he criticises Polybius for making the number six. The five zones + accepted by Strabo are as follows: the uninhabitable torrid zone lying in + the region of the equator; a zone on either side of this extending to the + tropic; and then the temperate zones extending in either direction from + the tropic to the arctic regions. There seems to have been a good deal of + dispute among the scholars of the time as to the exact arrangement of + these zones, but the general idea that the north-temperate zone is the + part of the earth with which the geographer deals seemed clearly + established. That the south-temperate zone would also present a habitable + area is an idea that is sometimes suggested, though seldom or never + distinctly expressed. It is probable that different opinions were held as + to this, and no direct evidence being available, a cautiously scientific + geographer like Strabo would naturally avoid the expression of an opinion + regarding it. Indeed, his own words leave us somewhat in doubt as to the + precise character of his notion regarding the zones. Perhaps we shall do + best to quote them: + </p> + <p> + "Let the earth be supposed to consist of five zones. (1) The equatorial + circle described around it. (2) Another parallel to this, and defining the + frigid zone of the northern hemisphere. (3) A circle passing through the + poles and cutting the two preceding circles at right-angles. The northern + hemisphere contains two quarters of the earth, which are bounded by the + equator and circle passing through the poles. Each of these quarters + should be supposed to contain a four-sided district, its northern side + being of one-half of the parallel next the pole, its southern by the half + of the equator, and its remaining sides by two segments of the circle + drawn through the poles, opposite to each other, and equal in length. In + one of these (which of them is of no consequence) the earth which we + inhabit is situated, surrounded by a sea and similar to an island. This, + as we said before, is evident both to our senses and to our reason. But + let any one doubt this, it makes no difference so far as geography is + concerned whether you believe the portion of the earth which we inhabit to + be an island or only admit what we know from experience—namely, that + whether you start from the east or the west you may sail all around it. + Certain intermediate spaces may have been left (unexplored), but these are + as likely to be occupied by sea as uninhabited land. The object of the + geographer is to describe known countries. Those which are unknown he + passes over equally with those beyond the limits of the inhabited earth. + It will, therefore, be sufficient for describing the contour of the island + we have been speaking of, if we join by a right line the outmost points + which, up to this time, have been explored by voyagers along the coast on + either side."(3) + </p> + <p> + We may pass over the specific criticisms of Strabo upon various + explorations that seem to have been of great interest to his + contemporaries, including an alleged trip of one Eudoxus out into the + Atlantic, and the journeyings of Pytheas in the far north. It is Pytheas, + we may add, who was cited by Hipparchus as having made the mistaken + observation that the length of the shadow of the gnomon is the same at + Marseilles and Byzantium, hence that these two places are on the same + parallel. Modern commentators have defended Pytheas as regards this + observation, claiming that it was Hipparchus and not Pytheas who made the + second observation from which the faulty induction was drawn. The point is + of no great significance, however, except as showing that a correct method + of determining the problems of latitude had thus early been suggested. + That faulty observations and faulty application of the correct principle + should have been made is not surprising. Neither need we concern ourselves + with the details as to the geographical distances, which Strabo found so + worthy of criticism and controversy. But in leaving the great geographer + we may emphasize his point of view and that of his contemporaries by + quoting three fundamental principles which he reiterates as being among + the "facts established by natural philosophers." He tells us that "(1) The + earth and heavens are spheroidal. (2) The tendency of all bodies having + weight is towards a centre. (3) Further, the earth being spheroidal and + having the same centre as the heavens, is motionless, as well as the axis + that passes through both it and the heavens. The heavens turn round both + the earth and its axis, from east to west. The fixed stars turn round with + it at the same rate as the whole. These fixed stars follow in their course + parallel circles, the principal of which are the equator, two tropics, and + the arctic circles; while the planets, the sun, and the moon describe + certain circles comprehended within the zodiac."(4) + </p> + <p> + Here, then, is a curious mingling of truth and error. The Pythagorean + doctrine that the earth is round had become a commonplace, but it would + appear that the theory of Aristarchus, according to which the earth is in + motion, has been almost absolutely forgotten. Strabo does not so much as + refer to it; neither, as we shall see, is it treated with greater respect + by the other writers of the period. + </p> + <p> + TWO FAMOUS EXPOSITORS—PLINY AND PTOLEMY + </p> + <p> + While Strabo was pursuing his geographical studies at Alexandria, a young + man came to Rome who was destined to make his name more widely known in + scientific annals than that of any other Latin writer of antiquity. This + man was Plinius Secundus, who, to distinguish him from his nephew, a + famous writer in another field, is usually spoken of as Pliny the Elder. + There is a famous story to the effect that the great Roman historian Livy + on one occasion addressed a casual associate in the amphitheatre at Rome, + and on learning that the stranger hailed from the outlying Spanish + province of the empire, remarked to him, "Yet you have doubtless heard of + my writings even there." "Then," replied the stranger, "you must be either + Livy or Pliny." + </p> + <p> + The anecdote illustrates the wide fame which the Roman naturalist achieved + in his own day. And the records of the Middle Ages show that this + popularity did not abate in succeeding times. Indeed, the Natural History + of Pliny is one of the comparatively few bulky writings of antiquity that + the efforts of copyists have preserved to us almost entire. It is, indeed, + a remarkable work and eminently typical of its time; but its author was an + industrious compiler, not a creative genius. As a monument of industry it + has seldom been equalled, and in this regard it seems the more remarkable + inasmuch as Pliny was a practical man of affairs who occupied most of his + life as a soldier fighting the battles of the empire. He compiled his book + in the leisure hours stolen from sleep, often writing by the light of the + camp-fire. Yet he cites or quotes from about four thousand works, most of + which are known to us only by his references. Doubtless Pliny added much + through his own observations. We know how keen was his desire to + investigate, since he lost his life through attempting to approach the + crater of Vesuvius on the occasion of that memorable eruption which buried + the cities of Herculaneum and Pompeii. + </p> + <p> + Doubtless the wandering life of the soldier had given Pliny abundant + opportunity for personal observation in his favorite fields of botany and + zoology. But the records of his own observations are so intermingled with + knowledge drawn from books that it is difficult to distinguish the one + from the other. Nor does this greatly matter, for whether as + closet-student or field-naturalist, Pliny's trait of mind is essentially + that of the compiler. He was no philosophical thinker, no generalizer, no + path-maker in science. He lived at the close of a great progressive epoch + of thought; in one of those static periods when numberless observers piled + up an immense mass of details which might advantageously be sorted into a + kind of encyclopaedia. Such an encyclopaedia is the so-called Natural + History of Pliny. It is a vast jumble of more or less uncritical + statements regarding almost every field of contemporary knowledge. The + descriptions of animals and plants predominate, but the work as a whole + would have been immensely improved had the compiler shown a more critical + spirit. As it is, he seems rather disposed to quote any interesting + citation that he comes across in his omnivorous readings, shielding + himself behind an equivocal "it is said," or "so and so alleges." A single + illustration will suffice to show what manner of thing is thought worthy + of repetition. + </p> + <p> + "It is asserted," he says, "that if the fish called a sea-star is smeared + with the fox's blood and then nailed to the upper lintel of the door, or + to the door itself, with a copper nail, no noxious spell will be able to + obtain admittance, or, at all events, be productive of any ill effects." + </p> + <p> + It is easily comprehensible that a work fortified with such practical + details as this should have gained wide popularity. Doubtless the natural + histories of our own day would find readier sale were they to pander to + various superstitions not altogether different from that here suggested. + The man, for example, who believes that to have a black cat cross his path + is a lucky omen would naturally find himself attracted by a book which + took account of this and similar important details of natural history. + Perhaps, therefore, it was its inclusion of absurdities, quite as much as + its legitimate value, that gave vogue to the celebrated work of Pliny. But + be that as it may, the most famous scientist of Rome must be remembered as + a popular writer rather than as an experimental worker. In the history of + the promulgation of scientific knowledge his work is important; in the + history of scientific principles it may virtually be disregarded. + </p> + <p> + PTOLEMY, THE LAST GREAT ASTRONOMER OF ANTIQUITY + </p> + <p> + Almost the same thing may be said of Ptolemy, an even more celebrated + writer, who was born not very long after the death of Pliny. The exact + dates of Ptolemy's life are not known, but his recorded observations + extend to the year 151 A.D. He was a working astronomer, and he made at + least one original discovery of some significance—namely, the + observation of a hitherto unrecorded irregularity of the moon's motion, + which came to be spoken of as the moon's evection. This consists of + periodical aberrations from the moon's regular motion in its orbit, which, + as we now know, are due to the gravitation pull of the sun, but which + remained unexplained until the time of Newton. Ptolemy also made original + observations as to the motions of the planets. He is, therefore, entitled + to a respectable place as an observing astronomer; but his chief fame + rests on his writings. + </p> + <p> + His great works have to do with geography and astronomy. In the former + field he makes an advance upon Strabo, citing the latitude of no fewer + than five thousand places. In the field of astronomy, his great service + was to have made known to the world the labors of Hipparchus. Ptolemy has + been accused of taking the star-chart of his great predecessor without due + credit, and indeed it seems difficult to clear him of this charge. Yet it + is at least open to doubt whether he intended any impropriety, inasmuch as + he all along is sedulous in his references to his predecessor. Indeed, his + work might almost be called an exposition of the astronomical doctrines of + Hipparchus. No one pretends that Ptolemy is to be compared with the + Rhodesian observer as an original investigator, but as a popular expounder + his superiority is evidenced in the fact that the writings of Ptolemy + became practically the sole astronomical text-book of the Middle Ages both + in the East and in the West, while the writings of Hipparchus were allowed + to perish. + </p> + <p> + The most noted of all the writings of Ptolemy is the work which became + famous under the Arabic name of Almagest. This word is curiously derived + from the Greek title (gr h megisth suntazis), "the greatest construction," + a name given the book to distinguish it from a work on astrology in four + books by the same author. For convenience of reference it came to be + spoken of merely as (gr h megisth), from which the Arabs form the title + Tabair al Magisthi, under which title the book was published in the year + 827. From this it derived the word Almagest, by which Ptolemy's work + continued to be known among the Arabs, and subsequently among Europeans + when the book again became known in the West. Ptolemy's book, as has been + said, is virtually an elaboration of the doctrines of Hipparchus. It + assumes that the earth is the fixed centre of the solar system, and that + the stars and planets revolve about it in twenty-four hours, the earth + being, of course, spherical. It was not to be expected that Ptolemy should + have adopted the heliocentric idea of Aristarchus. Yet it is much to be + regretted that he failed to do so, since the deference which was accorded + his authority throughout the Middle Ages would doubtless have been + extended in some measure at least to this theory as well, had he + championed it. Contrariwise, his unqualified acceptance of the geocentric + doctrine sufficed to place that doctrine beyond the range of challenge. + </p> + <p> + The Almagest treats of all manner of astronomical problems, but the + feature of it which gained it widest celebrity was perhaps that which has + to do with eccentrics and epicycles. This theory was, of course, but an + elaboration of the ideas of Hipparchus; but, owing to the celebrity of the + expositor, it has come to be spoken of as the theory of Ptolemy. We have + sufficiently detailed the theory in speaking of Hipparchus. It should be + explained, however, that, with both Hipparchus and Ptolemy, the theory of + epicycles would appear to have been held rather as a working hypothesis + than as a certainty, so far as the actuality of the minor spheres or + epicycles is concerned. That is to say, these astronomers probably did not + conceive either the epicycles or the greater spheres as constituting + actual solid substances. Subsequent generations, however, put this + interpretation upon the theory, conceiving the various spheres as actual + crystalline bodies. It is difficult to imagine just how the various + epicycles were supposed to revolve without interfering with the major + spheres, but perhaps this is no greater difficulty than is presented by + the alleged properties of the ether, which physicists of to-day accept as + at least a working hypothesis. We shall see later on how firmly the + conception of concentric crystalline spheres was held to, and that no real + challenge was ever given that theory until the discovery was made that + comets have an orbit that must necessarily intersect the spheres of the + various planets. + </p> + <p> + Ptolemy's system of geography in eight books, founded on that of Marinus + of Tyre, was scarcely less celebrated throughout the Middle Ages than the + Almagest. It contained little, however, that need concern us here, being + rather an elaboration of the doctrines to which we have already + sufficiently referred. None of Ptolemy's original manuscripts has come + down to us, but there is an alleged fifth-century manuscript attributed to + Agathadamon of Alexandria which has peculiar interest because it contains + a series of twenty-seven elaborately colored maps that are supposed to be + derived from maps drawn up by Ptolemy himself. In these maps the sea is + colored green, the mountains red or dark yellow, and the land white. + Ptolemy assumed that a degree at the equator was 500 stadia instead of 604 + stadia in length. We are not informed as to the grounds on which this + assumption was made, but it has been suggested that the error was at least + partially instrumental in leading to one very curious result. "Taking the + parallel of Rhodes," says Donaldson,(5) "he calculated the longitudes from + the Fortunate Islands to Cattigara or the west coast of Borneo at 180 + degrees, conceiving this to be one-half the circumference of the globe. + The real distance is only 125 degrees or 127 degrees, so that his + measurement is wrong by one third of the whole, one-sixth for the error in + the measurement of a degree and one-sixth for the errors in measuring the + distance geometrically. These errors, owing to the authority attributed to + the geography of Ptolemy in the Middle Ages, produced a consequence of the + greatest importance. They really led to the discovery of America. For the + design of Columbus to sail from the west of Europe to the east of Asia was + founded on the supposition that the distance was less by one third than it + really was." This view is perhaps a trifle fanciful, since there is + nothing to suggest that the courage of Columbus would have balked at the + greater distance, and since the protests of the sailors, which nearly + thwarted his efforts, were made long before the distance as estimated by + Ptolemy had been covered; nevertheless it is interesting to recall that + the great geographical doctrines, upon which Columbus must chiefly have + based his arguments, had been before the world in an authoritative form + practically unheeded for more than twelve hundred years, awaiting a + champion with courage enough to put them to the test. + </p> + <p> + GALEN—THE LAST GREAT ALEXANDRIAN + </p> + <p> + There is one other field of scientific investigation to which we must give + brief attention before leaving the antique world. This is the field of + physiology and medicine. In considering it we shall have to do with the + very last great scientist of the Alexandrian school. This was Claudius + Galenus, commonly known as Galen, a man whose fame was destined to eclipse + that of all other physicians of antiquity except Hippocrates, and whose + doctrines were to have the same force in their field throughout the Middle + Ages that the doctrines of Aristotle had for physical science. But before + we take up Galen's specific labors, it will be well to inquire briefly as + to the state of medical art and science in the Roman world at the time + when the last great physician of antiquity came upon the scene. + </p> + <p> + The Romans, it would appear, had done little in the way of scientific + discoveries in the field of medicine, but, nevertheless, with their + practicality of mind, they had turned to better account many more of the + scientific discoveries of the Greeks than did the discoverers themselves. + The practising physicians in early Rome were mostly men of Greek origin, + who came to the capital after the overthrow of the Greeks by the Romans. + Many of them were slaves, as earning money by either bodily or mental + labor was considered beneath the dignity of a Roman citizen. The wealthy + Romans, who owned large estates and numerous slaves, were in the habit of + purchasing some of these slave doctors, and thus saving medical fees by + having them attend to the health of their families. + </p> + <p> + By the beginning of the Christian era medicine as a profession had sadly + degenerated, and in place of a class of physicians who practised medicine + along rational or legitimate lines, in the footsteps of the great + Hippocrates, there appeared great numbers of "specialists," most of them + charlatans, who pretended to possess supernatural insight in the methods + of treating certain forms of disease. These physicians rightly earned the + contempt of the better class of Romans, and were made the object of many + attacks by the satirists of the time. Such specialists travelled about + from place to place in much the same manner as the itinerant "Indian + doctors" and "lightning tooth-extractors" do to-day. Eye-doctors seem to + have been particularly numerous, and these were divided into two classes, + eye-surgeons and eye-doctors proper. The eye-surgeon performed such + operations as cauterizing for ingrowing eyelashes and operating upon + growths about the eyes; while the eye-doctors depended entirely upon + salves and lotions. These eye-salves were frequently stamped with the seal + of the physician who compounded them, something like two hundred of these + seals being still in existence. There were besides these quacks, however, + reputable eye-doctors who must have possessed considerable skill in the + treatment of certain ophthalmias. Among some Roman surgical instruments + discovered at Rheims were found also some drugs employed by ophthalmic + surgeons, and an analysis of these show that they contained, among other + ingredients, some that are still employed in the treatment of certain + affections of the eye. + </p> + <p> + One of the first steps taken in recognition of the services of physicians + was by Julius Caesar, who granted citizenship to all physicians practising + in Rome. This was about fifty years before the Christian era, and from + that time on there was a gradual improvement in the attitude of the Romans + towards the members of the medical profession. As the Romans degenerated + from a race of sturdy warriors and became more and more depraved + physically, the necessity for physicians made itself more evident. Court + physicians, and physicians-in-ordinary, were created by the emperors, as + were also city and district physicians. In the year 133 A.D. Hadrian + granted immunity from taxes and military service to physicians in + recognition of their public services. + </p> + <p> + The city and district physicians, known as the archiatri populaires, + treated and cared for the poor without remuneration, having a position and + salary fixed by law and paid them semi-annually. These were honorable + positions, and the archiatri were obliged to give instruction in medicine, + without pay, to the poor students. They were allowed to receive fees and + donations from their patients, but not, however, until the danger from the + malady was past. Special laws were enacted to protect them, and any person + subjecting them to an insult was liable to a fine "not exceeding one + thousand pounds." + </p> + <p> + An example of Roman practicality is shown in the method of treating + hemorrhage, as described by Aulus Cornelius Celsus (53 B.C. to 7 A.D.). + Hippocrates and Hippocratic writers treated hemorrhage by application of + cold, pressure, styptics, and sometimes by actual cauterizing; but they + knew nothing of the simple method of stopping a hemorrhage by a ligature + tied around the bleeding vessel. Celsus not only recommended tying the end + of the injured vessel, but describes the method of applying two ligatures + before the artery is divided by the surgeon—a common practice among + surgeons at the present time. The cut is made between these two, and thus + hemorrhage is avoided from either end of the divided vessel. + </p> + <p> + Another Roman surgeon, Heliodorus, not only describes the use of the + ligature in stopping hemorrhage, but also the practice of torsion—twisting + smaller vessels, which causes their lining membrane to contract in a + manner that produces coagulation and stops hemorrhage. It is remarkable + that so simple and practical a method as the use of the ligature in + stopping hemorrhage could have gone out of use, once it had been + discovered; but during the Middle Ages it was almost entirely lost sight + of, and was not reintroduced until the time of Ambroise Pare, in the + sixteenth century. + </p> + <p> + Even at a very early period the Romans recognized the advantage of + surgical methods on the field of battle. Each soldier was supplied with + bandages, and was probably instructed in applying them, something in the + same manner as is done now in all modern armies. The Romans also made use + of military hospitals and had established a rude but very practical + field-ambulance service. "In every troop or bandon of two or four hundred + men, eight or ten stout fellows were deputed to ride immediately behind + the fighting-line to pick up and rescue the wounded, for which purpose + their saddles had two stirrups on the left side, while they themselves + were provided with water-flasks, and perhaps applied temporary bandages. + They were encouraged by a reward of a piece of gold for each man they + rescued. 'Noscomi' were male nurses attached to the military hospitals, + but not inscribed 'on strength' of the legions, and were probably for the + most part of the servile class."(6) + </p> + <p> + From the time of the early Alexandrians, Herophilus and Erasistratus, + whose work we have already examined, there had been various anatomists of + some importance in the Alexandrian school, though none quite equal to + these earlier workers. The best-known names are those of Celsus (of whom + we have already spoken), who continued the work of anatomical + investigation, and Marinus, who lived during the reign of Nero, and Rufus + of Ephesus. Probably all of these would have been better remembered by + succeeding generations had their efforts not been eclipsed by those of + Galen. This greatest of ancient anatomists was born at Pergamus of Greek + parents. His father, Nicon, was an architect and a man of considerable + ability. Until his fifteenth year the youthful Galen was instructed at + home, chiefly by his father; but after that time he was placed under + suitable teachers for instruction in the philosophical systems in vogue at + that period. Shortly after this, however, the superstitious Nicon, + following the interpretations of a dream, decided that his son should take + up the study of medicine, and placed him under the instruction of several + learned physicians. + </p> + <p> + Galen was a tireless worker, making long tours into Asia Minor and + Palestine to improve himself in pharmacology, and studying anatomy for + some time at Alexandria. He appears to have been full of the superstitions + of the age, however, and early in his career made an extended tour into + western Asia in search of the chimerical "jet-stone"—a stone + possessing the peculiar qualities of "burning with a bituminous odor and + supposed to possess great potency in curing such diseases as epilepsy, + hysteria, and gout." + </p> + <p> + By the time he had reached his twenty-eighth year he had perfected his + education in medicine and returned to his home in Pergamus. Even at that + time he had acquired considerable fame as a surgeon, and his + fellow-citizens showed their confidence in his ability by choosing him as + surgeon to the wounded gladiators shortly after his return to his native + city. In these duties his knowledge of anatomy aided him greatly, and he + is said to have healed certain kinds of wounds that had previously baffled + the surgeons. + </p> + <p> + In the time of Galen dissections of the human body were forbidden by law, + and he was obliged to confine himself to dissections of the lower animals. + He had the advantage, however, of the anatomical works of Herophilus and + Erasistratus, and he must have depended upon them in perfecting his + comparison between the anatomy of men and the lower animals. It is + possible that he did make human dissections surreptitiously, but of this + we have no proof. + </p> + <p> + He was familiar with the complicated structure of the bones of the + cranium. He described the vertebrae clearly, divided them into groups, and + named them after the manner of anatomists of to-day. He was less accurate + in his description of the muscles, although a large number of these were + described by him. Like all anatomists before the time of Harvey, he had a + very erroneous conception of the circulation, although he understood that + the heart was an organ for the propulsion of blood, and he showed that the + arteries of the living animals did not contain air alone, as was taught by + many anatomists. He knew, also, that the heart was made up of layers of + fibres that ran in certain fixed directions—that is, longitudinal, + transverse, and oblique; but he did not recognize the heart as a muscular + organ. In proof of this he pointed out that all muscles require rest, and + as the heart did not rest it could not be composed of muscular tissue. + </p> + <p> + Many of his physiological experiments were conducted upon scientific + principles. Thus he proved that certain muscles were under the control of + definite sets of nerves by cutting these nerves in living animals, and + observing that the muscles supplied by them were rendered useless. He + pointed out also that nerves have no power in themselves, but merely + conduct impulses to and from the brain and spinal-cord. He turned this + peculiar knowledge to account in the case of a celebrated sophist, + Pausanias, who had been under the treatment of various physicians for a + numbness in the fourth and fifth fingers of his left hand. These + physicians had been treating this condition by applications of poultices + to the hand itself. Galen, being called in consultation, pointed out that + the injury was probably not in the hand itself, but in the ulner nerve, + which controls sensation in the fourth and fifth fingers. Surmising that + the nerve must have been injured in some way, he made careful inquiries of + the patient, who recalled that he had been thrown from his chariot some + time before, striking and injuring his back. Acting upon this information, + Galen applied stimulating remedies to the source of the nerve itself—that + is, to the bundle of nerve-trunks known as the brachial plexus, in the + shoulder. To the surprise and confusion of his fellow-physicians, this + method of treatment proved effective and the patient recovered completely + in a short time. + </p> + <p> + Although the functions of the organs in the chest were not well understood + by Galen, he was well acquainted with their anatomy. He knew that the + lungs were covered by thin membrane, and that the heart was surrounded by + a sac of very similar tissue. He made constant comparisons also between + these organs in different animals, as his dissections were performed upon + beasts ranging in size from a mouse to an elephant. The minuteness of his + observations is shown by the fact that he had noted and described the ring + of bone found in the hearts of certain animals, such as the horse, + although not found in the human heart or in most animals. + </p> + <p> + His description of the abdominal organs was in general accurate. He had + noted that the abdominal cavity was lined with a peculiar saclike + membrane, the peritoneum, which also surrounded most of the organs + contained in the cavity, and he made special note that this membrane also + enveloped the liver in a peculiar manner. The exactness of the last + observation seems the more wonderful when we reflect that even to-day the + medical, student finds a correct understanding of the position of the + folds of the peritoneum one of the most difficult subjects in anatomy. + </p> + <p> + As a practical physician he was held in the highest esteem by the Romans. + The Emperor Marcus Aurelius called him to Rome and appointed him + physician-inordinary to his son Commodus, and on special occasions Marcus + Aurelius himself called in Galen as his medical adviser. On one occasion, + the three army surgeons in attendance upon the emperor declared that he + was about to be attacked by a fever. Galen relates how "on special command + I felt his pulse, and finding it quite normal, considering his age and the + time of day, I declared it was no fever but a digestive disorder, due to + the food he had eaten, which must be converted into phlegm before being + excreted. Then the emperor repeated three times, 'That's the very thing,' + and asked what was to be done. I answered that I usually gave a glass of + wine with pepper sprinkled on it, but for you kings we only use the safest + remedies, and it will suffice to apply wool soaked in hot nard ointment + locally. The emperor ordered the wool, wine, etc., to be brought, and I + left the room. His feet were warmed by rubbing with hot hands, and after + drinking the peppered wine, he said to Pitholaus (his son's tutor), 'We + have only one doctor, and that an honest one,' and went on to describe me + as the first of physicians and the only philosopher, for he had tried many + before who were not only lovers of money, but also contentious, ambitious, + envious, and malignant."(7) + </p> + <p> + It will be seen from this that Galen had a full appreciation of his own + abilities as a physician, but inasmuch as succeeding generations for a + thousand years concurred in the alleged statement made by Marcus Aurelius + as to his ability, he is perhaps excusable for his open avowal of his + belief in his powers. His faith in his accuracy in diagnosis and prognosis + was shown when a colleague once said to him, "I have used the prognostics + of Hippocrates as well as you. Why can I not prognosticate as well as + you?" To this Galen replied, "By God's help I have never been deceived in + my prognosis."(8) It is probable that this statement was made in the heat + of argument, and it is hardly to be supposed that he meant it literally. + </p> + <p> + His systems of treatment were far in advance of his theories regarding the + functions of organs, causes of disease, etc., and some of them are still + first principles with physicians. Like Hippocrates, he laid great stress + on correct diet, exercise, and reliance upon nature. "Nature is the + overseer by whom health is supplied to the sick," he says. "Nature lends + her aid on all sides, she decides and cures diseases. No one can be saved + unless nature conquers the disease, and no one dies unless nature + succumbs." + </p> + <p> + From the picture thus drawn of Galen as an anatomist and physician, one + might infer that he should rank very high as a scientific exponent of + medicine, even in comparison with modern physicians. There is, however, + another side to the picture. His knowledge of anatomy was certainly very + considerable, but many of his deductions and theories as to the functions + of organs, the cause of diseases, and his methods of treating them, would + be recognized as absurd by a modern school-boy of average intelligence. + His greatness must be judged in comparison with ancient, not with modern, + scientists. He maintained, for example, that respiration and the + pulse-beat were for one and the same purpose—that of the reception + of air into the arteries of the body. To him the act of breathing was for + the purpose of admitting air into the lungs, whence it found its way into + the heart, and from there was distributed throughout the body by means of + the arteries. The skin also played an important part in supplying the body + with air, the pores absorbing the air and distributing it through the + arteries. But, as we know that he was aware of the fact that the arteries + also contained blood, he must have believed that these vessels contained a + mixture of the two. + </p> + <p> + Modern anatomists know that the heart is divided into two approximately + equal parts by an impermeable septum of tough fibres. Yet, Galen, who + dissected the hearts of a vast number of the lower animals according to + his own account, maintained that this septum was permeable, and that the + air, entering one side of the heart from the lungs, passed through it into + the opposite side and was then transferred to the arteries. + </p> + <p> + He was equally at fault, although perhaps more excusably so, in his + explanation of the action of the nerves. He had rightly pointed out that + nerves were merely connections between the brain and spinal-cord and + distant muscles and organs, and had recognized that there were two kinds + of nerves, but his explanation of the action of these nerves was that + "nervous spirits" were carried to the cavities of the brain by + blood-vessels, and from there transmitted through the body along the + nerve-trunks. + </p> + <p> + In the human skull, overlying the nasal cavity, there are two thin plates + of bone perforated with numerous small apertures. These apertures allow + the passage of numerous nerve-filaments which extend from a group of cells + in the brain to the delicate membranes in the nasal cavity. These + perforations in the bone, therefore, are simply to allow the passage of + the nerves. But Galen gave a very different explanation. He believed that + impure "animal spirits" were carried to the cavities of the brain by the + arteries in the neck and from there were sifted out through these + perforated bones, and so expelled from the body. + </p> + <p> + He had observed that the skin played an important part in cooling the + body, but he seems to have believed that the heart was equally active in + overheating it. The skin, therefore, absorbed air for the purpose of + "cooling the heart," and this cooling process was aided by the brain, + whose secretions aided also in the cooling process. The heart itself was + the seat of courage; the brain the seat of the rational soul; and the + liver the seat of love. + </p> + <p> + The greatness of Galen's teachings lay in his knowledge of anatomy of the + organs; his weakness was in his interpretations of their functions. + Unfortunately, succeeding generations of physicians for something like a + thousand years rejected the former but clung to the latter, so that the + advances he had made were completely overshadowed by the mistakes of his + teachings. + </p> + <p> + <a name="link2H_4_0013" id="link2H_4_0013"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + </h2> + <p> + It is a favorite tenet of the modern historian that history is a + continuous stream. The contention has fullest warrant. Sharp lines of + demarcation are an evidence of man's analytical propensity rather than the + work of nature. Nevertheless it would be absurd to deny that the stream of + history presents an ever-varying current. There are times when it seems to + rush rapidly on; times when it spreads out into a broad—seemingly + static—current; times when its catastrophic changes remind us of + nothing but a gigantic cataract. Rapids and whirlpools, broad estuaries + and tumultuous cataracts are indeed part of the same stream, but they are + parts that vary one from another in their salient features in such a way + as to force the mind to classify them as things apart and give them + individual names. + </p> + <p> + So it is with the stream of history; however strongly we insist on its + continuity we are none the less forced to recognize its periodicity. It + may not be desirable to fix on specific dates as turning-points to the + extent that our predecessors were wont to do. We may not, for example, be + disposed to admit that the Roman Empire came to any such cataclysmic + finish as the year 476 A.D., when cited in connection with the overthrow + of the last Roman Empire of the West, might seem to indicate. But, on the + other hand, no student of the period can fail to realize that a great + change came over the aspect of the historical stream towards the close of + the Roman epoch. + </p> + <p> + The span from Thales to Galen has compassed about eight hundred years—let + us say thirty generations. Throughout this period there is scarcely a + generation that has not produced great scientific thinkers—men who + have put their mark upon the progress of civilization; but we shall see, + as we look forward for a corresponding period, that the ensuing thirty + generations produced scarcely a single scientific thinker of the first + rank. Eight hundred years of intellectual activity—thirty + generations of greatness; then eight hundred years of stasis—thirty + generations of mediocrity; such seems to be the record as viewed in + perspective. Doubtless it seemed far different to the contemporary + observer; it is only in reasonable perspective that any scene can be + viewed fairly. But for us, looking back without prejudice across the stage + of years, it seems indisputable that a great epoch came to a close at + about the time when the barbarian nations of Europe began to sweep down + into Greece and Italy. We are forced to feel that we have reached the + limits of progress of what historians are pleased to call the ancient + world. For about eight hundred years Greek thought has been dominant, but + in the ensuing period it is to play a quite subordinate part, except in so + far as it influences the thought of an alien race. As we leave this + classical epoch, then, we may well recapitulate in brief its triumphs. A + few words will suffice to summarize a story the details of which have made + up our recent chapters. + </p> + <p> + In the field of cosmology, Greek genius has demonstrated that the earth is + spheroidal, that the moon is earthlike in structure and much smaller than + our globe, and that the sun is vastly larger and many times more distant + than the moon. The actual size of the earth and the angle of its axis with + the ecliptic have been measured with approximate accuracy. It has been + shown that the sun and moon present inequalities of motion which may be + theoretically explained by supposing that the earth is not situated + precisely at the centre of their orbits. A system of eccentrics and + epicycles has been elaborated which serves to explain the apparent motions + of the heavenly bodies in a manner that may be called scientific even + though it is based, as we now know, upon a false hypothesis. The true + hypothesis, which places the sun at the centre of the planetary system and + postulates the orbital and axial motions of our earth in explanation of + the motions of the heavenly bodies, has been put forward and ardently + championed, but, unfortunately, is not accepted by the dominant thinkers + at the close of our epoch. In this regard, therefore, a vast revolutionary + work remains for the thinkers of a later period. Moreover, such + observations as the precession of the equinoxes and the moon's evection + are as yet unexplained, and measurements of the earth's size, and of the + sun's size and distance, are so crude and imperfect as to be in one case + only an approximation, and in the other an absurdly inadequate suggestion. + But with all these defects, the total achievement of the Greek astronomers + is stupendous. To have clearly grasped the idea that the earth is round is + in itself an achievement that marks off the classical from the Oriental + period as by a great gulf. + </p> + <p> + In the physical sciences we have seen at least the beginnings of great + things. Dynamics and hydrostatics may now, for the first time, claim a + place among the sciences. Geometry has been perfected and trigonometry has + made a sure beginning. The conception that there are four elementary + substances, earth, water, air, and fire, may not appear a secure + foundation for chemistry, yet it marks at least an attempt in the right + direction. Similarly, the conception that all matter is made up of + indivisible particles and that these have adjusted themselves and are + perhaps held in place by a whirling motion, while it is scarcely more than + a scientific dream, is, after all, a dream of marvellous insight. + </p> + <p> + In the field of biological science progress has not been so marked, yet + the elaborate garnering of facts regarding anatomy, physiology, and the + zoological sciences is at least a valuable preparation for the + generalizations of a later time. + </p> + <p> + If with a map before us we glance at the portion of the globe which was + known to the workers of the period now in question, bearing in mind at the + same time what we have learned as to the seat of labors of the various + great scientific thinkers from Thales to Galen, we cannot fail to be + struck with a rather startling fact, intimations of which have been given + from time to time—the fact, namely, that most of the great Greek + thinkers did not live in Greece itself. As our eye falls upon Asia Minor + and its outlying islands, we reflect that here were born such men as + Thales, Anaximander, Anaximenes, Heraclitus, Pythagoras, Anaxagoras, + Socrates, Aristarchus, Hipparchus, Eudoxus, Philolaus, and Galen. From the + northern shores of the aegean came Lucippus, Democritus, and Aristotle. + Italy, off to the west, is the home of Pythagoras and Xenophanes in their + later years, and of Parmenides and Empedocles, Zeno, and Archimedes. + Northern Africa can claim, by birth or by adoption, such names as Euclid, + Apollonius of Perga, Herophilus, Erasistratus, Aristippus, Eratosthenes, + Ctesibius, Hero, Strabo, and Ptolemy. This is but running over the list of + great men whose discoveries have claimed our attention. Were we to extend + the list to include a host of workers of the second rank, we should but + emphasize the same fact. + </p> + <p> + All along we are speaking of Greeks, or, as they call themselves, + Hellenes, and we mean by these words the people whose home was a small + jagged peninsula jutting into the Mediterranean at the southeastern + extremity of Europe. We think of this peninsula as the home of Greek + culture, yet of all the great thinkers we have just named, not one was + born on this peninsula, and perhaps not one in five ever set foot upon it. + In point of fact, one Greek thinker of the very first rank, and one only, + was born in Greece proper; that one, however, was Plato, perhaps the + greatest of them all. With this one brilliant exception (and even he was + born of parents who came from the provinces), all the great thinkers of + Greece had their origin at the circumference rather than the centre of the + empire. And if we reflect that this circumference of the Greek world was + in the nature of the case the widely circling region in which the Greek + came in contact with other nations, we shall see at once that there could + be no more striking illustration in all history than that furnished us + here of the value of racial mingling as a stimulus to intellectual + progress. + </p> + <p> + But there is one other feature of the matter that must not be overlooked. + Racial mingling gives vitality, but to produce the best effect the + mingling must be that of races all of which are at a relatively high plane + of civilization. In Asia Minor the Greek mingled with the Semite, who had + the heritage of centuries of culture; and in Italy with the Umbrians, + Oscans, and Etruscans, who, little as we know of their antecedents, have + left us monuments to testify to their high development. The chief reason + why the racial mingling of a later day did not avail at once to give new + life to Roman thought was that the races which swept down from the north + were barbarians. It was no more possible that they should spring to the + heights of classical culture than it would, for example, be possible in + two or three generations to produce a racer from a stock of draught + horses. Evolution does not proceed by such vaults as this would imply. + Celt, Goth, Hun, and Slav must undergo progressive development for many + generations before the population of northern Europe can catch step with + the classical Greek and prepare to march forward. That, perhaps, is one + reason why we come to a period of stasis or retrogression when the time of + classical activity is over. But, at best, it is only one reason of + several. + </p> + <p> + The influence of the barbarian nations will claim further attention as we + proceed. But now, for the moment, we must turn our eyes in the other + direction and give attention to certain phases of Greek and of Oriental + thought which were destined to play a most important part in the + development of the Western mind—a more important part, indeed, in + the early mediaeval period than that played by those important inductions + of science which have chiefly claimed our attention in recent chapters. + The subject in question is the old familiar one of false inductions or + pseudoscience. In dealing with the early development of thought and with + Oriental science, we had occasion to emphasize the fact that such false + inductions led everywhere to the prevalence of superstition. In dealing + with Greek science, we have largely ignored this subject, confining + attention chiefly to the progressive phases of thought; but it must not be + inferred from this that Greek science, with all its secure inductions, was + entirely free from superstition. On the contrary, the most casual + acquaintance with Greek literature would suffice to show the incorrectness + of such a supposition. True, the great thinkers of Greece were probably + freer from this thraldom of false inductions than any of their + predecessors. Even at a very early day such men as Xenophanes, Empedocles, + Anaxagoras, and Plato attained to a singularly rationalistic conception of + the universe. + </p> + <p> + We saw that "the father of medicine," Hippocrates, banished demonology and + conceived disease as due to natural causes. At a slightly later day the + sophists challenged all knowledge, and Pyrrhonism became a synonym for + scepticism in recognition of the leadership of a master doubter. The + entire school of Alexandrians must have been relatively free from + superstition, else they could not have reasoned with such effective + logicality from their observations of nature. It is almost inconceivable + that men like Euclid and Archimedes, and Aristarchus and Eratosthenes, and + Hipparchus and Hero, could have been the victims of such illusions + regarding occult forces of nature as were constantly postulated by + Oriental science. Herophilus and Erasistratus and Galen would hardly have + pursued their anatomical studies with equanimity had they believed that + ghostly apparitions watched over living and dead alike, and exercised at + will a malign influence. + </p> + <p> + Doubtless the Egyptian of the period considered the work, of the Ptolemaic + anatomists an unspeakable profanation, and, indeed, it was nothing less + than revolutionary—so revolutionary that it could not be sustained + in subsequent generations. We have seen that the great Galen, at Rome, + five centuries after the time of Herophilus, was prohibited from + dissecting the human subject. The fact speaks volumes for the attitude of + the Roman mind towards science. Vast audiences made up of every stratum of + society thronged the amphitheatre, and watched exultingly while man slew + his fellow-man in single or in multiple combat. Shouts of frenzied joy + burst from a hundred thousand throats when the death-stroke was given to a + new victim. The bodies of the slain, by scores, even by hundreds, were + dragged ruthlessly from the arena and hurled into a ditch as + contemptuously as if pity were yet unborn and human life the merest + bauble. Yet the same eyes that witnessed these scenes with ecstatic + approval would have been averted in pious horror had an anatomist dared to + approach one of the mutilated bodies with the scalpel of science. It was + sport to see the blade of the gladiator enter the quivering, living flesh + of his fellow-gladiator; it was joy to see the warm blood spurt forth from + the writhing victim while he still lived; but it were sacrilegious to + approach that body with the knife of the anatomist, once it had ceased to + pulsate with life. Life itself was held utterly in contempt, but about the + realm of death hovered the threatening ghosts of superstition. And such, + be it understood, was the attitude of the Roman populace in the early and + the most brilliant epoch of the empire, before the Western world came + under the influence of that Oriental philosophy which was presently to + encompass it. + </p> + <p> + In this regard the Alexandrian world was, as just intimated, far more + advanced than the Roman, yet even there we must suppose that the leaders + of thought were widely at variance with the popular conceptions. A few + illustrations, drawn from Greek literature at various ages, will suggest + the popular attitude. In the first instance, consider the poems of Homer + and of Hesiod. For these writers, and doubtless for the vast majority of + their readers, not merely of their own but of many subsequent generations, + the world is peopled with a multitude of invisible apparitions, which, + under title of gods, are held to dominate the affairs of man. It is + sometimes difficult to discriminate as to where the Greek imagination drew + the line between fact and allegory; nor need we attempt to analyse the + early poetic narratives to this end. It will better serve our present + purpose to cite three or four instances which illustrate the tangibility + of beliefs based upon pseudo-scientific inductions. + </p> + <p> + Let us cite, for example, the account which Herodotus gives us of the + actions of the Greeks at Plataea, when their army confronted the remnant + of the army of Xerxes, in the year 479 B.C. Here we see each side + hesitating to attack the other, merely because the oracle had declared + that whichever side struck the first blow would lose the conflict. Even + after the Persian soldiers, who seemingly were a jot less superstitious or + a shade more impatient than their opponents, had begun the attack, we are + told that the Greeks dared not respond at first, though they were falling + before the javelins of the enemy, because, forsooth, the entrails of a + fowl did not present an auspicious appearance. And these were Greeks of + the same generation with Empedocles and Anaxagoras and aeschylus; of the + same epoch with Pericles and Sophocles and Euripides and Phidias. Such was + the scientific status of the average mind—nay, of the best minds—with + here and there a rare exception, in the golden age of Grecian culture. + </p> + <p> + Were we to follow down the pages of Greek history, we should but repeat + the same story over and over. We should, for example, see Alexander the + Great balked at the banks of the Hyphasis, and forced to turn back because + of inauspicious auguries based as before upon the dissection of a fowl. + Alexander himself, to be sure, would have scorned the augury; had he been + the prey of such petty superstitions he would never have conquered Asia. + We know how he compelled the oracle at Delphi to yield to his wishes; how + he cut the Gordian knot; how he made his dominating personality felt at + the temple of Ammon in Egypt. We know, in a word, that he yielded to + superstitions only in so far as they served his purpose. Left to his own + devices, he would not have consulted an oracle at the banks of the + Hyphasis; or, consulting, would have forced from the oracle a favorable + answer. But his subordinates were mutinous and he had no choice. Suffice + it for our present purpose that the oracle was consulted, and that its + answer turned the conqueror back. + </p> + <p> + One or two instances from Roman history may complete the picture. Passing + over all those mythical narratives which virtually constitute the early + history of Rome, as preserved to us by such historians as Livy and + Dionysius, we find so logical an historian as Tacitus recording a + miraculous achievement of Vespasian without adverse comment. "During the + months when Vespasian was waiting at Alexandria for the periodical season + of the summer winds, and a safe navigation, many miracles occurred by + which the favor of Heaven and a sort of bias in the powers above towards + Vespasian were manifested." Tacitus then describes in detail the cure of + various maladies by the emperor, and relates that the emperor on visiting + a temple was met there, in the spirit, by a prominent Egyptian who was + proved to be at the same time some eighty miles distant from Alexandria. + </p> + <p> + It must be admitted that Tacitus, in relating that Vespasian caused the + blind to see and the lame to walk, qualifies his narrative by asserting + that "persons who are present attest the truth of the transaction when + there is nothing to be gained by falsehood." Nor must we overlook the fact + that a similar belief in the power of royalty has persisted almost to our + own day. But no such savor of scepticism attaches to a narrative which + Dion Cassius gives us of an incident in the life of Marcus Aurelius—an + incident that has become famous as the episode of The Thundering Legion. + Xiphilinus has preserved the account of Dion, adding certain picturesque + interpretations of his own. The original narrative, as cited, asserts that + during one of the northern campaigns of Marcus Aurelius, the emperor and + his army were surrounded by the hostile Quadi, who had every advantage of + position and who presently ceased hostilities in the hope that heat and + thirst would deliver their adversaries into their hands without the + trouble of further fighting. "Now," says Dion, "while the Romans, unable + either to combat or to retreat, and reduced to the last extremity by + wounds, fatigue, heat, and thirst, were standing helplessly at their + posts, clouds suddenly gathered in great number and rain descended in + floods—certainly not without divine intervention, since the Egyptian + Maege Arnulphis, who was with Marcus Antoninus, is said to have invoked + several genii by the aerial mercury by enchantment, and thus through them + had brought down rain." + </p> + <p> + Here, it will be observed, a supernatural explanation is given of a + natural phenomenon. But the narrator does not stop with this. If we are to + accept the account of Xiphilinus, Dion brings forward some striking proofs + of divine interference. Xiphilinus gives these proofs in the following + remarkable paragraph: + </p> + <p> + "Dion adds that when the rain began to fall every soldier lifted his head + towards heaven to receive the water in his mouth; but afterwards others + hold out their shields or their helmets to catch the water for themselves + and for their horses. Being set upon by the barbarians... while occupied + in drinking, they would have been seriously incommoded had not heavy hail + and numerous thunderbolts thrown consternation into the ranks of the + enemy. Fire and water were seen to mingle as they left the heavens. The + fire, however, did not reach the Romans, but if it did by chance touch one + of them it was immediately extinguished, while at the same time the rain, + instead of comforting the barbarians, seemed merely to excite like oil the + fire with which they were being consumed. Some barbarians inflicted wounds + upon themselves as though their blood had power to extinguish flames, + while many rushed over to the side of the Romans, hoping that there water + might save them." + </p> + <p> + We cannot better complete these illustrations of pagan credulity than by + adding the comment of Xiphilinus himself. That writer was a Christian, + living some generations later than Dion. He never thought of questioning + the facts, but he felt that Dion's interpretation of these facts must not + go unchallenged. As he interprets the matter, it was no pagan magician + that wrought the miracle. He even inclines to the belief that Dion himself + was aware that Christian interference, and not that of an Egyptian, saved + the day. "Dion knew," he declares, "that there existed a legion called The + Thundering Legion, which name was given it for no other reason than for + what came to pass in this war," and that this legion was composed of + soldiers from Militene who were all professed Christians. "During the + battle," continues Xiphilinus, "the chief of the Pretonians, had set at + Marcus Antoninus, who was in great perplexity at the turn events were + taking, representing to him that there was nothing the people called + Christians could not obtain by their prayers, and that among his forces + was a troop composed wholly of followers of that religion. Rejoiced at + this news, Marcus Antoninus demanded of these soldiers that they should + pray to their god, who granted their petition on the instant, sent + lightning among the enemy and consoled the Romans with rain. Struck by + this wonderful success, the emperor honored the Christians in an edict and + named their legion The Thundering. It is even asserted that a letter + existed by Marcus Antoninus on this subject. The pagans well knew that the + company was called The Thunderers, having attested the fact themselves, + but they revealed nothing of the occasion on which the leader received the + name."(1) + </p> + <p> + Peculiar interest attaches to this narrative as illustrating both + credulousness as to matters of fact and pseudo-scientific explanation of + alleged facts. The modern interpreter may suppose that a violent + thunderstorm came up during the course of a battle between the Romans and + the so-called barbarians, and that owing to the local character of the + storm, or a chance discharge of lightning, the barbarians suffered more + than their opponents. We may well question whether the philosophical + emperor himself put any other interpretation than this upon the incident. + But, on the other hand, we need not doubt that the major part of his + soldiers would very readily accept such an explanation as that given by + Dion Cassius, just as most readers of a few centuries later would accept + the explanation of Xiphilinus. It is well to bear this thought in mind in + considering the static period of science upon which we are entering. We + shall perhaps best understand this period, and its seeming retrogressions, + if we suppose that the average man of the Middle Ages was no more + credulous, no more superstitious, than the average Roman of an earlier + period or than the average Greek; though the precise complexion of his + credulity had changed under the influence of Oriental ideas, as we have + just seen illustrated by the narrative of Xiphilinus. + </p> + <p> + <a name="link2H_APPE" id="link2H_APPE"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + APPENDIX + </h2> + <h3> + REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES + </h3> + <p> + <a name="link2HCH0001" id="link2HCH0001"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER I. PREHISTORIC SCIENCE + </h2> + <p> + Length of the Prehistoric Period.—It is of course quite impossible + to reduce the prehistoric period to any definite number of years. There + are, however, numerous bits of evidence that enable an anthropologist to + make rough estimates as to the relative lengths of the different periods + into which prehistoric time is divided. Gabriel de Mortillet, one of the + most industrious students of prehistoric archaeology, ventured to give a + tentative estimate as to the numbers of years involved in each period. He + of course claimed for this nothing more than the value of a scientific + guess. It is, however, a guess based on a very careful study of all data + at present available. Mortillet divides the prehistoric period, as a + whole, into four epochs. The first of these is the preglacial, which he + estimates as comprising seventy-eight thousand years; the second is the + glacial, covering one hundred thousand years; then follows what he terms + the Solutreen, which numbers eleven thousand years; and, finally, the + Magdalenien, comprising thirty-three thousand years. This gives, for the + prehistoric period proper, a term of about two hundred and twenty-two + thousand years. Add to this perhaps twelve thousand years ushering in the + civilization of Egypt, and the six thousand years of stable, sure + chronology of the historical period, and we have something like two + hundred and thirty thousand or two hundred and forty thousand years as the + age of man. + </p> + <p> + "These figures," says Mortillet, "are certainly not exaggerated. It is + even probable that they are below the truth. Constantly new discoveries + are being made that tend to remove farther back the date of man's + appearance." We see, then, according to this estimate, that about a + quarter of a million years have elapsed since man evolved to a state that + could properly be called human. This guess is as good as another, and it + may advantageously be kept in mind, as it will enable us all along to + understand better than we might otherwise be able to do the tremendous + force of certain prejudices and preconceptions which recent man inherited + from his prehistoric ancestor. Ideas which had passed current as + unquestioned truths for one hundred thousand years or so are not easily + cast aside. + </p> + <p> + In going back, in imagination, to the beginning of the prehistoric period, + we must of course reflect, in accordance with modern ideas on the subject, + that there was no year, no millennium even, when it could be said + expressly: "This being was hitherto a primate, he is now a man." The + transition period must have been enormously long, and the changes from + generation to generation, even from century to century, must have been + very slight. In speaking of the extent of the age of man this must be + borne in mind: it must be recalled that, even if the period were not vague + for other reasons, the vagueness of its beginning must make it + indeterminate. + </p> + <p> + Bibliographical Notes.—A great mass of literature has been produced + in recent years dealing with various phases of the history of prehistoric + man. No single work known to the writer deals comprehensively with the + scientific attainments of early man; indeed, the subject is usually + ignored, except where practical phases of the mechanical arts are in + question. But of course any attempt to consider the condition of primitive + man talies into account, by inference at least, his knowledge and + attainments. Therefore, most works on anthropology, ethnology, and + primitive culture may be expected to throw some light on our present + subject. Works dealing with the social and mental conditions of existing + savages are also of importance, since it is now an accepted belief that + the ancestors of civilized races evolved along similar lines and passed + through corresponding stages of nascent culture. Herbert Spencer's + Descriptive Sociology presents an unequalled mass of facts regarding + existing primitive races, but, unfortunately, its inartistic method of + arrangement makes it repellent to the general reader. E. B. Tyler's + Primitive Culture and Anthropology; Lord Avebury's Prehistoric Times, The + Origin of Civilization, and The Primitive Condition of Man; W. Boyd + Dawkin's Cave-Hunting and Early Man in Britain; and Edward Clodd's + Childhood of the World and Story of Primitive Man are deservedly popular. + Paul Topinard's Elements d'Anthropologie Generale is one of the best-known + and most comprehensive French works on the technical phases of + anthropology; but Mortillet's Le Prehistorique has a more popular + interest, owing to its chapters on primitive industries, though this work + also contains much that is rather technical. Among periodicals, the Revue + de l'Ecole d'Anthropologie de Paris, published by the professors, treats + of all phases of anthropology, and the American Anthropologist, edited by + F. W. Hodge for the American Anthropological Association, and intended as + "a medium of communication between students of all branches of + anthropology," contains much that is of interest from the present + stand-point. The last-named journal devotes a good deal of space to Indian + languages. + </p> + <p> + <a name="link2HCH0002" id="link2HCH0002"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER II. EGYPTIAN SCIENCE + </h2> + <p> + 1 (p. 34). Sir J. Norman Lockyer, The Dawn of Astronomy; a study of the + temple worship and mythology of the ancient Egyptians, London, 1894. + </p> + <p> + 2 (p. 43). G. Maspero, Histoire Ancie-nne des Peuples de l'Orient + Classique, Paris, 1895. Translated as (1) The Dawn of Civilization, (2) + The Struggle of the Nations, (3) The Passing of the Empires, 3 vols., + London and New York, 1894-1900. Professor Maspero is one of the most + famous of living Orientalists. His most important special studies have to + do with Egyptology, but his writings cover the entire field of Oriental + antiquity. He is a notable stylist, and his works are at once readable and + authoritative. + </p> + <p> + 3 (p. 44). Adolf Erman, Life in Ancient Egypt, London, 1894, p. 352. + (Translated from the original German work entitled Aegypten und + aegyptisches Leben in Alterthum, Tilbigen, 1887.) An altogether admirable + work, full of interest for the general reader, though based on the most + erudite studies. + </p> + <p> + 4 (p. 47). Erman, op. cit., pp. 356, 357. + </p> + <p> + 5 (p. 48). Erman, op. cit., p. 357. The work on Egyptian medicine here + referred to is Georg Ebers' edition of an Egyptian document discovered by + the explorer whose name it bears. It remains the most important source of + our knowledge of Egyptian medicine. As mentioned in the text, this + document dates from the eighteenth dynasty—that is to say, from + about the fifteenth or sixteenth century, B.C., a relatively late period + of Egyptian history. + </p> + <p> + 6 (p. 49). Erman, op. cit., p. 357. + </p> + <p> + 7 (p. 50). The History of Herodotus, pp. 85-90. There are numerous + translations of the famous work of the "father of history," one of the + most recent and authoritative being that of G. C. Macaulay, M.A., in two + volumes, Macmillan & Co., London and New York, 1890. + </p> + <p> + 8 (p. 50). The Historical Library of Diodorus the Sicilian, London, 1700. + This most famous of ancient world histories is difficult to obtain in an + English version. The most recently published translation known to the + writer is that of G. Booth, London, 1814. + </p> + <p> + 9 (p. 51). Erman, op. cit., p. 357. + </p> + <p> + 10 (p. 52). The Papyrus Rhind is a sort of mathematical hand-book of the + ancient Egyptians; it was made in the time of the Hyksos Kings (about 2000 + B.C.), but is a copy of an older book. It is now preserved in the British + Museum. + </p> + <p> + The most accessible recent sources of information as to the social + conditions of the ancient Egyptians are the works of Maspero and Erman, + above mentioned; and the various publications of W. M. Flinders Petrie, + The Pyramids and Temples of Gizeh, London, 1883; Tanis I., London, 1885; + Tanis H., Nebesheh, and Defe-nnel, London, 1887; Ten Years' Diggings, + London, 1892; Syria and Egypt from the Tel-el-Amar-na Letters, London, + 1898, etc. The various works of Professor Petrie, recording his + explorations from year to year, give the fullest available insight into + Egyptian archaeology. + </p> + <p> + <a name="link2HCH0003" id="link2HCH0003"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + </h2> + <p> + 1 (p. 57). The Medes. Some difference of opinion exists among historians + as to the exact ethnic relations of the conquerors; the precise date of + the fall of Nineveh is also in doubt. + </p> + <p> + 2 (p. 57). Darius. The familiar Hebrew narrative ascribes the first + Persian conquest of Babylon to Darius, but inscriptions of Cyrus and of + Nabonidus, the Babylonian king, make it certain that Cyrus was the real + conqueror. These inscriptions are preserved on cylinders of baked clay, of + the type made familiar by the excavation of the past fifty years, and they + are invaluable historical documents. + </p> + <p> + 3 (p. 58). Berosus. The fragments of Berosus have been translated by L. P. + Cory, and included in his Ancient Fragments of Phenician, Chaldean, + Egyptian, and Other Writers, London, 1826, second edition, 1832. + </p> + <p> + 4 (p. 58). Chaldean learning. Recent writers reserve the name Chaldean for + the later period of Babylonian history—the time when the Greeks came + in contact with the Mesopotamians—in contradistinction to the + earlier periods which are revealed to us by the archaeological records. + </p> + <p> + 5 (p. 59) King Sargon of Agade. The date given for this early king must + not be accepted as absolute; but it is probably approximately correct. + </p> + <p> + 6 (p. 59). Nippur. See the account of the early expeditions as recorded by + the director, Dr. John P. Peters, Nippur, or explorations and adventures, + etc., New York and London, 1897. + </p> + <p> + 7 (p. 62). Fritz Hommel, Geschichte Babyloniens und Assyriens, Berlin, + 1885. + </p> + <p> + 8 (p. 63). R. Campbell Thompson, Reports of the Magicians and Astrologers + of Nineveh and Babylon, London, 1900, p. xix. + </p> + <p> + 9 (p. 64). George Smith, The Assyrian Canon, p. 21. + </p> + <p> + 10 (p. 64). Thompson, op. cit., p. xix. + </p> + <p> + 11 (p. 65). Thompson, op. cit., p. 2. + </p> + <p> + 12 (p. 67). Thompson, op. cit., p. xvi. + </p> + <p> + 13 (p. 68). Sextus Empiricus, author of Adversus Mathematicos, lived about + 200 A.D. + </p> + <p> + 14 (p. 68). R. Campbell Thompson, op. cit., p. xxiv. + </p> + <p> + 15 (p. 72). Records of the Past (editor, Samuel Birch), Vol. III., p. 139. + </p> + <p> + 16 (p. 72). Ibid., Vol. V., p. 16. + </p> + <p> + 17 (p. 72). Quoted in Records of the Past, Vol. III., p. 143, from the + Translations of the Society of Biblical Archeology, vol. II., p. 58. + </p> + <p> + 18 (p. 73). Records of the Past, vol. L, p. 131. + </p> + <p> + 19 (p. 73). Ibid., vol. V., p. 171. + </p> + <p> + 20 (p. 74). Ibid., vol. V., p. 169. + </p> + <p> + 21 (p. 74). Joachim Menant, La Bibliotheque du Palais de Ninive, Paris, + 1880. + </p> + <p> + 22 (p. 76). Code of Khamurabi. This famous inscription is on a block of + black diorite nearly eight feet in height. It was discovered at Susa by + the French expedition under M. de Morgan, in December, 1902. We quote the + translation given in The Historians' History of the World, edited by Henry + Smith Williams, London and New York, 1904, Vol. I, p. 510. + </p> + <p> + 23 (p. 77). The Historical Library of Diodorus Siculus, p. 519. + </p> + <p> + 24 (p. 82). George S. Goodspeed, Ph.D., History of the Babylonians and + Assyrians, New York, 1902. + </p> + <p> + 25 (p. 82). George Rawlinson, Great Oriental Monarchies, (second edition, + London, 1871), Vol. III., pp. 75 ff. + </p> + <p> + Of the books mentioned above, that of Hommel is particularly full in + reference to culture development; Goodspeed's small volume gives an + excellent condensed account; the original documents as translated in the + various volumes of Records of the Past are full of interest; and Menant's + little book is altogether admirable. The work of excavation is still going + on in old Babylonia, and newly discovered texts add from time to time to + our knowledge, but A. H. Layard's Nineveh and its Remains (London, 1849) + still has importance as a record of the most important early discoveries. + The general histories of Antiquity of Duncker, Lenormant, Maspero, and + Meyer give full treatment of Babylonian and Assyrian development. Special + histories of Babylonia and Assyria, in addition to these named above, are + Tiele's Babylonisch-Assyrische Geschichte (Zwei Tiele, Gotha, 1886-1888); + Winckler's Geschichte Babyloniens und Assyriens (Berlin, 1885-1888), and + Rogers' History of Babylonia and Assyria, New York and London, 1900, the + last of which, however, deals almost exclusively with political history. + Certain phases of science, particularly with reference to chronology and + cosmology, are treated by Edward Meyer (Geschichte des Alterthum, Vol. I., + Stuttgart, 1884), and by P. Jensen (Die Kosmologie der Babylonier, + Strassburg, 1890), but no comprehensive specific treatment of the subject + in its entirety has yet been attempted. + </p> + <p> + <a name="link2HCH0004" id="link2HCH0004"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + </h2> + <p> + 1 (p. 87). Vicomte E. de Rouge, Memoire sur l'Origine Egyptienne de + l'Alphabet Phinicien, Paris, 1874. + </p> + <p> + 2 (p. 88). See the various publications of Mr. Arthur Evans. + </p> + <p> + 3 (p. 80). Aztec and Maya writing. These pictographs are still in the main + undecipherable, and opinions differ as to the exact stage of development + which they represent. + </p> + <p> + 4 (p. 90). E. A. Wallace Budge's First Steps in Egyptian, London, 1895, is + an excellent elementary work on the Egyptian writing. Professor Erman's + Egyptian Grammar, London, 1894, is the work of perhaps the foremost living + Egyptologist. + </p> + <p> + 5 (P. 93). Extant examples of Babylonian and Assyrian writing give + opportunity to compare earlier and later systems, so the fact of evolution + from the pictorial to the phonetic system rests on something more than + mere theory. + </p> + <p> + 6 (p. 96). Friedrich Delitzsch, Assyrischc Lesestucke mit grammatischen + Tabellen und vollstdndigem Glossar einfiihrung in die assyrische und + babylonische Keilschrift-litteratur bis hinauf zu Hammurabi, Leipzig, + 1900. + </p> + <p> + 7 (p. 97). It does not appear that the Babylonians thcmselves ever gave up + the old system of writing, so long as they retained political autonomy. + </p> + <p> + 8 (p. 101). See Isaac Taylor's History of the Alphabet; an Account of the + origin and Development of Letters, new edition, 2 vols., London, 1899. + </p> + <p> + For facsimiles of the various scripts, see Henry Smith Williams' History + of the Art Of Writing, 4 vols, New York and London, 1902-1903. + </p> + <p> + <a name="link2HCH0005" id="link2HCH0005"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + </h2> + <p> + 1 (p. III). Anaximander, as recorded by Plutarch, vol. VIII-. See Arthur + Fairbanks'First Philosophers of Greece: an Edition and Translation of the + Remaining Fragments of the Pre-Socratic Philosophers, together with a + Translation of the more Important Accounts of their Opinions Contained in + the Early Epitomcs of their Works, London, 1898. This highly scholarly and + extremely useful book contains the Greek text as well as translations. + </p> + <p> + <a name="link2HCH0006" id="link2HCH0006"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + </h2> + <p> + 1 (p. 117). George Henry Lewes, A Biographical History of Philosophy from + its Origin in Greece down to the Present Day, enlarged edition, New York, + 1888, p. 17. + </p> + <p> + 2 (p. 121). Diogenes Laertius, The Lives and Opinions of Eminent + Philosophers, C. D. Yonge's translation, London, 1853, VIII., p. 153. + </p> + <p> + 3 (p. 121). Alexander, Successions of Philosophers. + </p> + <p> + 4 (p. 122). "All over its centre." Presumably this is intended to refer to + the entire equatorial region. + </p> + <p> + 5 (p. 125). Laertius, op. cit., pp. 348-351. + </p> + <p> + 6 (p. 128). Arthur Fairbanks, The First Philosophers of Greece London, + 1898, pp. 67-717. + </p> + <p> + 7 (p. 129). Ibid., p. 838. + </p> + <p> + 8 (p. 130). Ibid., p. 109. + </p> + <p> + 9 (p. 130). Heinrich Ritter, The History of Ancient Philosophy, translated + from the German by A. J. W. Morrison, 4 vols., London, 1838, vol, I., p. + 463. + </p> + <p> + 10 (p. 131). Ibid., p. 465. + </p> + <p> + 11 (p. 132). George Henry Lewes, op. cit., p. 81. + </p> + <p> + 12 (p. 135). Fairbanks, op. cit., p. 201. + </p> + <p> + 13 (p. 136). Ibid., P. 234. + </p> + <p> + 14 (p. 137). Ibid., p. 189. + </p> + <p> + 15 (p. 137). Ibid., P. 220. + </p> + <p> + 16 (p. 138). Ibid., p. 189. + </p> + <p> + 17 (p. 138). Ibid., p. 191. + </p> + <p> + <a name="link2HCH0007" id="link2HCH0007"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + </h2> + <p> + 1 (p. 150). Theodor Gomperz, Greek Thinkers: a History of Ancient + Philosophy (translated from the German by Laurie Magnes), New York, 190 1, + pp. 220, 221. + </p> + <p> + 2 (p. 153). Aristotle's Treatise on Respiration, ch. ii. + </p> + <p> + 3 (p. 159). Fairbanks' translation of the fragments of Anaxagoras, in The + First Philosophers of Greece, pp. 239-243. + </p> + <p> + <a name="link2HCH0008" id="link2HCH0008"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + </h2> + <p> + 1 (p. 180). Alfred William Bern, The Philosophy of Greece Considered in + Relation to the Character and History of its People, London, 1898, p. 186. + </p> + <p> + 2 (p. 183). Aristotle, quoted in William Whewell's History of the + Inductive Sciences (second edition, London, 1847), Vol. II., p. 161. + </p> + <p> + <a name="link2HCH0009" id="link2HCH0009"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + </h2> + <h3> + 1 (p. 195). Tertullian's Apologeticus. + </h3> + <p> + 2 (p. 205). We quote the quaint old translation of North, printed in 1657. + </p> + <p> + <a name="link2HCH0010" id="link2HCH0010"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER X. SCIENCE OF THE ROMAN PERIOD + </h2> + <p> + 1 (p. 258). The Geography of Strabo, translated by H. C. Hamilton and W. + Falconer, 3 vols., London, 1857, Vol. I, pp. 19, 20. + </p> + <p> + 2 (p. 260). Ibid., p. 154. + </p> + <p> + 3 (p. 263). Ibid., pp. 169, 170. + </p> + <p> + 4 (p. 264) Ibid., pp. 166, 167. + </p> + <p> + 5 (p. 271). K. 0. Miller and John W. Donaldson, The History of the + Literature of Greece, 3 vols., London, Vol. III., p. 268. + </p> + <p> + 6 (p. 276). E. T. Withington, Medical History fron., the Earliest Times, + London, 1894, p. 118. + </p> + <p> + 7 (p. 281). Ibid. + </p> + <p> + 8 (p. 281). Johann Hermann Bass, History of Medicine, New York, 1889. + </p> + <p> + <a name="link2HCH0011" id="link2HCH0011"> + <!-- H2 anchor --> </a> + </p> + <div style="height: 4em;"> + <br /><br /><br /><br /> + </div> + <h2> + CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + </h2> + <p> + (p. 298). Dion Cassius, as preserved by Xiphilinus. Our extract is quoted + from the translation given in The Historians' History of the World (edited + by Henry Smith Williams), 25 vols., London and New York, 1904, Vol. VI., + p. 297 ff. + </p> + <p> + (For further bibliographical notes, the reader is referred to the Appendix + of volume V.) + </p> + <p> + <br /> <br /> + </p> + <hr /> + <hr /> + <p> + <br /> <br /> + </p> + <h1> + TABLE OF CONTENTS <br /><br /> FOR THE FIVE VOLUMES + </h1> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0002"> <b>BOOK + I</b> </a> + </p> + <table summary="" style="margin-right: auto; margin-left: auto"> + <tr> + <td> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0003"> + I. PREHISTORIC SCIENCE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0004"> + II. EGYPTIAN SCIENCE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0005"> + III. SCIENCE OF BABYLONIA AND ASSYRIA </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0006"> + IV. THE DEVELOPMENT OF THE ALPHABET </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0007"> + V. THE BEGINNINGS OF GREEK SCIENCE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0008"> + VI. THE EARLY GREEK PHILOSOPHERS IN ITALY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0009"> + VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0010"> + VIII. POST-SOCRATIC SCIENCE AT ATHENS—PLATO, ARISTOTLE, AND + THEOPHRASTUS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0011"> + IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0012"> + X. SCIENCE OF THE ROMAN PERIOD </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1705/1705-h/1705-h.htm#2H_4_0013"> + XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE </a> + </p> + </td> + </tr> + </table> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0002"> <b>BOOK + II. THE BEGINNINGS OF MODERN SCIENCE</b> </a> + </p> + <table summary="" style="margin-right: auto; margin-left: auto"> + <tr> + <td> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0003"> + I. SCIENCE IN THE DARK AGE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0004"> + II. MEDIAEVAL SCIENCE AMONG THE ARABIANS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0005"> + III. MEDIAEVAL SCIENCE IN THE WEST </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0006"> + IV. THE NEW COSMOLOGY—COPERNICUS TO KEPLER AND GALILEO </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0007"> + V. GALILEO AND THE NEW PHYSICS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0008"> + VI. TWO PSEUDO-SCIENCES—ALCHEMY AND ASTROLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0009"> + VII. FROM PARACELSUS TO HARVEY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0010"> + VIII. MEDICINE IN THE SIXTEENTH AND SEVENTEENTH CENTURIES </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0011"> + IX. PHILOSOPHER-SCIENTISTS AND NEW INSTITUTIONS OF LEARNING </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0012"> + X. THE SUCCESSORS OF GALILEO IN PHYSICAL SCIENCE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0013"> + XI. NEWTON AND THE COMPOSITION OF LIGHT </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0014"> + XII. NEWTON AND THE LAW OF GRAVITATION </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0015"> + XIII. INSTRUMENTS OF PRECISION IN THE AGE OF NEWTON </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0016"> + XIV. PROGRESS IN ELECTRICITY FROM GILBERT AND VON GUERICKE TO + FRANKLIN </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1706/1706-h/1706-h.htm#2H_4_0017"> + XV. NATURAL HISTORY TO THE TIME OF LINNAEUS </a> + </p> + </td> + </tr> + </table> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0001"> <b>BOOK + III. MODERN DEVELOPMENT OF THE PHYSICAL SCIENCES</b> </a> + </p> + <table summary="" style="margin-right: auto; margin-left: auto"> + <tr> + <td> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0002"> + I. THE SUCCESSORS OF NEWTON IN ASTRONOMY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0003"> + II. THE PROGRESS OF MODERN ASTRONOMY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0004"> + III. THE NEW SCIENCE OF PALEONTOLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0005"> + IV. THE ORIGIN AND DEVELOPMENT OF MODERN GEOLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0006"> + V. THE NEW SCIENCE OF METEOROLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0007"> + VI. MODERN THEORIES OF HEAT AND LIGHT </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0008"> + VII. THE MODERN DEVELOPMENT OF ELECTRICITY AND MAGNETISM </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0009"> + VIII. THE CONSERVATION OF ENERGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1707/1707-h/1707-h.htm#2H_4_0010"> + IX. THE ETHER AND PONDERABLE MATTER </a> + </p> + </td> + </tr> + </table> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0001"> <b>BOOK + IV. MODERN DEVELOPMENT OF THE CHEMICAL AND BIOLOGICAL SCIENCES</b> </a> + </p> + <table summary="" style="margin-right: auto; margin-left: auto"> + <tr> + <td> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0002"> + I. THE PHLOGISTON THEORY IN CHEMISTRY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0003"> + II. THE BEGINNINGS OF MODERN CHEMISTRY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0004"> + III. CHEMISTRY SINCE THE TIME OF DALTON </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0005"> + IV. ANATOMY AND PHYSIOLOGY IN THE EIGHTEENTH CENTURY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0006"> + V. ANATOMY AND PHYSIOLOGY IN THE NINETEENTH CENTURY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0007"> + VI. THEORIES OF ORGANIC EVOLUTION </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0008"> + VII. EIGHTEENTH-CENTURY MEDICINE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0009"> + VIII. NINETEENTH-CENTURY MEDICINE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0010"> + IX. THE NEW SCIENCE OF EXPERIMENTAL PSYCHOLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/1708/1708-h/1708-h.htm#2H_4_0011"> + X. THE NEW SCIENCE OF ORIENTAL ARCHAEOLOGY </a> + </p> + </td> + </tr> + </table> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0001"> + <b>BOOK V. ASPECTS OF RECENT SCIENCE</b> </a><br /> + </p> + <table summary="" style="margin-right: auto; margin-left: auto"> + <tr> + <td> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0003"> + I. THE BRITISH MUSEUM </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0004"> + II. THE ROYAL SOCIETY OF LONDON FOR IMPROVING NATURAL KNOWLEDGE </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0005"> + III. THE ROYAL INSTITUTION AND THE LOW-TEMPERATURE RESEARCHES </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0006"> + IV. SOME PHYSICAL LABORATORIES AND PHYSICAL PROBLEMS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0007"> + V. THE MARINE BIOLOGICAL LABORATORY AT NAPLES </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0008"> + VI. ERNST HAECKEL AND THE NEW ZOOLOGY </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0009"> + VII. SOME MEDICAL LABORATORIES AND MEDICAL PROBLEMS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0010"> + VII. SOME UNSOLVED SCIENTIFIC PROBLEMS </a> + </p> + <p class="toc"> + <a + href="http://www.gutenberg.org/files/30495/30495-h/30495-h.htm#2H_4_0011"> + IX. RETROSPECT AND PROSPECT </a> + </p> + </td> + </tr> + </table> + <p> + <br /> <br /> + </p> + <hr /> + <p> + <br /> <br /> + </p> +<pre xml:space="preserve"> + + + + + +End of the Project Gutenberg EBook of A History of Science, Volume 1(of 5), by +Henry Smith Williams + +*** END OF THIS PROJECT GUTENBERG EBOOK HISTORY OF SCIENCE, V1 *** + +***** This file should be named 1705-h.htm or 1705-h.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/1/7/0/1705/ + +Produced by Charles Keller, and David Widger + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: A History of Science, Volume 1(of 5) + +Author: Henry Smith Williams + +Release Date: April, 1999 [Etext #1705] +Posting Date: November 17, 2009 + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK HISTORY OF SCIENCE, V1 *** + + + + +Produced by Charles Keller + + + + + +A HISTORY OF SCIENCE + +BY HENRY SMITH WILLIAMS, M.D., LL.D. + +ASSISTED BY EDWARD H. WILLIAMS, M.D. + +IN FIVE VOLUMES + + +VOLUME I. THE BEGINNINGS OF SCIENCE + + + + + BOOK I. + + CONTENTS + + CHAPTER I. PREHISTORIC SCIENCE + + CHAPTER II. EGYPTIAN SCIENCE + + CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + + CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + + CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + + CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + + CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + + CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + + CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + + CHAPTER X. SCIENCE OF THE ROMAN PERIOD + + CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + + APPENDIX + + + + +A HISTORY OF SCIENCE + + + + +BOOK I + +Should the story that is about to be unfolded be found to lack interest, +the writers must stand convicted of unpardonable lack of art. Nothing +but dulness in the telling could mar the story, for in itself it is +the record of the growth of those ideas that have made our race and its +civilization what they are; of ideas instinct with human interest, +vital with meaning for our race; fundamental in their influence on human +development; part and parcel of the mechanism of human thought on the +one hand, and of practical civilization on the other. Such a phrase as +"fundamental principles" may seem at first thought a hard saying, but +the idea it implies is less repellent than the phrase itself, for +the fundamental principles in question are so closely linked with the +present interests of every one of us that they lie within the grasp of +every average man and woman--nay, of every well-developed boy and girl. +These principles are not merely the stepping-stones to culture, the +prerequisites of knowledge--they are, in themselves, an essential part +of the knowledge of every cultivated person. + +It is our task, not merely to show what these principles are, but to +point out how they have been discovered by our predecessors. We shall +trace the growth of these ideas from their first vague beginnings. We +shall see how vagueness of thought gave way to precision; how a general +truth, once grasped and formulated, was found to be a stepping-stone to +other truths. We shall see that there are no isolated facts, no +isolated principles, in nature; that each part of our story is linked +by indissoluble bands with that which goes before, and with that which +comes after. For the most part the discovery of this principle or that +in a given sequence is no accident. Galileo and Keppler must precede +Newton. Cuvier and Lyall must come before Darwin;--Which, after all, is +no more than saying that in our Temple of Science, as in any other piece +of architecture, the foundation must precede the superstructure. + +We shall best understand our story of the growth of science if we think +of each new principle as a stepping-stone which must fit into its own +particular niche; and if we reflect that the entire structure of modern +civilization would be different from what it is, and less perfect than +it is, had not that particular stepping-stone been found and shaped and +placed in position. Taken as a whole, our stepping-stones lead us up and +up towards the alluring heights of an acropolis of knowledge, on which +stands the Temple of Modern Science. The story of the building of this +wonderful structure is in itself fascinating and beautiful. + + + + +I. PREHISTORIC SCIENCE + +To speak of a prehistoric science may seem like a contradiction of +terms. The word prehistoric seems to imply barbarism, while science, +clearly enough, seems the outgrowth of civilization; but rightly +considered, there is no contradiction. For, on the one hand, man had +ceased to be a barbarian long before the beginning of what we call the +historical period; and, on the other hand, science, of a kind, is no +less a precursor and a cause of civilization than it is a consequent. To +get this clearly in mind, we must ask ourselves: What, then, is science? +The word runs glibly enough upon the tongue of our every-day speech, but +it is not often, perhaps, that they who use it habitually ask themselves +just what it means. Yet the answer is not difficult. A little attention +will show that science, as the word is commonly used, implies these +things: first, the gathering of knowledge through observation; second, +the classification of such knowledge, and through this classification, +the elaboration of general ideas or principles. In the familiar +definition of Herbert Spencer, science is organized knowledge. + +Now it is patent enough, at first glance, that the veriest savage must +have been an observer of the phenomena of nature. But it may not be so +obvious that he must also have been a classifier of his observations--an +organizer of knowledge. Yet the more we consider the case, the more +clear it will become that the two methods are too closely linked +together to be dissevered. To observe outside phenomena is not more +inherent in the nature of the mind than to draw inferences from these +phenomena. A deer passing through the forest scents the ground and +detects a certain odor. A sequence of ideas is generated in the mind of +the deer. Nothing in the deer's experience can produce that odor but +a wolf; therefore the scientific inference is drawn that wolves have +passed that way. But it is a part of the deer's scientific knowledge, +based on previous experience, individual and racial; that wolves are +dangerous beasts, and so, combining direct observation in the present +with the application of a general principle based on past experience, +the deer reaches the very logical conclusion that it may wisely turn +about and run in another direction. All this implies, essentially, a +comprehension and use of scientific principles; and, strange as it seems +to speak of a deer as possessing scientific knowledge, yet there is +really no absurdity in the statement. The deer does possess scientific +knowledge; knowledge differing in degree only, not in kind, from the +knowledge of a Newton. Nor is the animal, within the range of its +intelligence, less logical, less scientific in the application of that +knowledge, than is the man. The animal that could not make accurate +scientific observations of its surroundings, and deduce accurate +scientific conclusions from them, would soon pay the penalty of its lack +of logic. + +What is true of man's precursors in the animal scale is, of course, true +in a wider and fuller sense of man himself at the very lowest stage +of his development. Ages before the time which the limitations of our +knowledge force us to speak of as the dawn of history, man had reached +a high stage of development. As a social being, he had developed all +the elements of a primitive civilization. If, for convenience of +classification, we speak of his state as savage, or barbaric, we use +terms which, after all, are relative, and which do not shut off our +primitive ancestors from a tolerably close association with our own +ideals. We know that, even in the Stone Age, man had learned how to +domesticate animals and make them useful to him, and that he had also +learned to cultivate the soil. Later on, doubtless by slow and painful +stages, he attained those wonderful elements of knowledge that enabled +him to smelt metals and to produce implements of bronze, and then of +iron. Even in the Stone Age he was a mechanic of marvellous skill, as +any one of to-day may satisfy himself by attempting to duplicate such an +implement as a chipped arrow-head. And a barbarian who could fashion +an axe or a knife of bronze had certainly gone far in his knowledge of +scientific principles and their practical application. The practical +application was, doubtless, the only thought that our primitive ancestor +had in mind; quite probably the question as to principles that might +be involved troubled him not at all. Yet, in spite of himself, he +knew certain rudimentary principles of science, even though he did not +formulate them. + +Let us inquire what some of these principles are. Such an inquiry will, +as it were, clear the ground for our structure of science. It will +show the plane of knowledge on which historical investigation begins. +Incidentally, perhaps, it will reveal to us unsuspected affinities +between ourselves and our remote ancestor. Without attempting anything +like a full analysis, we may note in passing, not merely what primitive +man knew, but what he did not know; that at least a vague notion may be +gained of the field for scientific research that lay open for historic +man to cultivate. + + +It must be understood that the knowledge of primitive man, as we are +about to outline it, is inferential. We cannot trace the development +of these principles, much less can we say who discovered them. Some of +them, as already suggested, are man's heritage from non-human ancestors. +Others can only have been grasped by him after he had reached a +relatively high stage of human development. But all the principles here +listed must surely have been parts of our primitive ancestor's knowledge +before those earliest days of Egyptian and Babylonian civilization, +the records of which constitute our first introduction to the so-called +historical period. Taken somewhat in the order of their probable +discovery, the scientific ideas of primitive man may be roughly listed +as follows: + +1. Primitive man must have conceived that the earth is flat and of +limitless extent. By this it is not meant to imply that he had a +distinct conception of infinity, but, for that matter, it cannot be said +that any one to-day has a conception of infinity that could be called +definite. But, reasoning from experience and the reports of travellers, +there was nothing to suggest to early man the limit of the earth. He +did, indeed, find in his wanderings, that changed climatic conditions +barred him from farther progress; but beyond the farthest reaches of +his migrations, the seemingly flat land-surfaces and water-surfaces +stretched away unbroken and, to all appearances, without end. It would +require a reach of the philosophical imagination to conceive a limit +to the earth, and while such imaginings may have been current in the +prehistoric period, we can have no proof of them, and we may well +postpone consideration of man's early dreamings as to the shape of the +earth until we enter the historical epoch where we stand on firm ground. + +2. Primitive man must, from a very early period, have observed that the +sun gives heat and light, and that the moon and stars seem to give light +only and no heat. It required but a slight extension of this observation +to note that the changing phases of the seasons were associated with the +seeming approach and recession of the sun. This observation, however, +could not have been made until man had migrated from the tropical +regions, and had reached a stage of mechanical development enabling him +to live in subtropical or temperate zones. Even then it is conceivable +that a long period must have elapsed before a direct causal relation was +felt to exist between the shifting of the sun and the shifting of the +seasons; because, as every one knows, the periods of greatest heat in +summer and greatest cold in winter usually come some weeks after the +time of the solstices. Yet, the fact that these extremes of temperature +are associated in some way with the change of the sun's place in the +heavens must, in time, have impressed itself upon even a rudimentary +intelligence. It is hardly necessary to add that this is not meant +to imply any definite knowledge of the real meaning of, the seeming +oscillations of the sun. We shall see that, even at a relatively late +period, the vaguest notions were still in vogue as to the cause of the +sun's changes of position. + +That the sun, moon, and stars move across the heavens must obviously +have been among the earliest scientific observations. It must not be +inferred, however, that this observation implied a necessary conception +of the complete revolution of these bodies about the earth. It is +unnecessary to speculate here as to how the primitive intelligence +conceived the transfer of the sun from the western to the eastern +horizon, to be effected each night, for we shall have occasion to +examine some historical speculations regarding this phenomenon. We may +assume, however, that the idea of the transfer of the heavenly bodies +beneath the earth (whatever the conception as to the form of that body) +must early have presented itself. + +It required a relatively high development of the observing faculties, +yet a development which man must have attained ages before the +historical period, to note that the moon has a secondary motion, which +leads it to shift its relative position in the heavens, as regards +the stars; that the stars themselves, on the other hand, keep a fixed +relation as regards one another, with the notable exception of two or +three of the most brilliant members of the galaxy, the latter being the +bodies which came to be known finally as planets, or wandering stars. +The wandering propensities of such brilliant bodies as Jupiter and Venus +cannot well have escaped detection. We may safely assume, however, that +these anomalous motions of the moon and planets found no explanation +that could be called scientific until a relatively late period. + +3. Turning from the heavens to the earth, and ignoring such primitive +observations as that of the distinction between land and water, we may +note that there was one great scientific law which must have forced +itself upon the attention of primitive man. This is the law of universal +terrestrial gravitation. The word gravitation suggests the name of +Newton, and it may excite surprise to hear a knowledge of gravitation +ascribed to men who preceded that philosopher by, say, twenty-five or +fifty thousand years. Yet the slightest consideration of the facts will +make it clear that the great central law that all heavy bodies fall +directly towards the earth, cannot have escaped the attention of the +most primitive intelligence. The arboreal habits of our primitive +ancestors gave opportunities for constant observation of the +practicalities of this law. And, so soon as man had developed the mental +capacity to formulate ideas, one of the earliest ideas must have been +the conception, however vaguely phrased in words, that all unsupported +bodies fall towards the earth. The same phenomenon being observed to +operate on water-surfaces, and no alteration being observed in its +operation in different portions of man's habitat, the most primitive +wanderer must have come to have full faith in the universal action of +the observed law of gravitation. Indeed, it is inconceivable that he can +have imagined a place on the earth where this law does not operate. +On the other hand, of course, he never grasped the conception of the +operation of this law beyond the close proximity of the earth. To extend +the reach of gravitation out to the moon and to the stars, including +within its compass every particle of matter in the universe, was the +work of Newton, as we shall see in due course. Meantime we shall +better understand that work if we recall that the mere local fact +of terrestrial gravitation has been the familiar knowledge of all +generations of men. It may further help to connect us in sympathy with +our primeval ancestor if we recall that in the attempt to explain this +fact of terrestrial gravitation Newton made no advance, and we of to-day +are scarcely more enlightened than the man of the Stone Age. Like the +man of the Stone Age, we know that an arrow shot into the sky falls +back to the earth. We can calculate, as he could not do, the arc it will +describe and the exact speed of its fall; but as to why it returns to +earth at all, the greatest philosopher of to-day is almost as much +in the dark as was the first primitive bowman that ever made the +experiment. + +Other physical facts going to make up an elementary science of +mechanics, that were demonstratively known to prehistoric man, were such +as these: the rigidity of solids and the mobility of liquids; the +fact that changes of temperature transform solids to liquids and vice +versa--that heat, for example, melts copper and even iron, and that +cold congeals water; and the fact that friction, as illustrated in the +rubbing together of two sticks, may produce heat enough to cause a fire. +The rationale of this last experiment did not receive an explanation +until about the beginning of the nineteenth century of our own era. +But the experimental fact was so well known to prehistoric man that he +employed this method, as various savage tribes employ it to this day, +for the altogether practical purpose of making a fire; just as he +employed his practical knowledge of the mutability of solids and liquids +in smelting ores, in alloying copper with tin to make bronze, and in +casting this alloy in molds to make various implements and weapons. +Here, then, were the germs of an elementary science of physics. +Meanwhile such observations as that of the solution of salt in water +may be considered as giving a first lesson in chemistry, but beyond such +altogether rudimentary conceptions chemical knowledge could not have +gone--unless, indeed, the practical observation of the effects of fire +be included; nor can this well be overlooked, since scarcely another +single line of practical observation had a more direct influence in +promoting the progress of man towards the heights of civilization. + +4. In the field of what we now speak of as biological knowledge, +primitive man had obviously the widest opportunity for practical +observation. We can hardly doubt that man attained, at an early day, to +that conception of identity and of difference which Plato places at +the head of his metaphysical system. We shall urge presently that it +is precisely such general ideas as these that were man's earliest +inductions from observation, and hence that came to seem the +most universal and "innate" ideas of his mentality. It is quite +inconceivable, for example, that even the most rudimentary intelligence +that could be called human could fail to discriminate between living +things and, let us say, the rocks of the earth. The most primitive +intelligence, then, must have made a tacit classification of the natural +objects about it into the grand divisions of animate and inanimate +nature. Doubtless the nascent scientist may have imagined life animating +many bodies that we should call inanimate--such as the sun, wandering +planets, the winds, and lightning; and, on the other hand, he may +quite likely have relegated such objects as trees to the ranks of the +non-living; but that he recognized a fundamental distinction between, +let us say, a wolf and a granite bowlder we cannot well doubt. A step +beyond this--a step, however, that may have required centuries +or millenniums in the taking--must have carried man to a plane of +intelligence from which a primitive Aristotle or Linnaeus was enabled +to note differences and resemblances connoting such groups of things +as fishes, birds, and furry beasts. This conception, to be sure, is an +abstraction of a relatively high order. We know that there are savage +races to-day whose language contains no word for such an abstraction as +bird or tree. We are bound to believe, then, that there were long ages +of human progress during which the highest man had attained no such +stage of abstraction; but, on the other hand, it is equally little in +question that this degree of mental development had been attained long +before the opening of our historical period. The primeval man, then, +whose scientific knowledge we are attempting to predicate, had become, +through his conception of fishes, birds, and hairy animals as separate +classes, a scientific zoologist of relatively high attainments. + +In the practical field of medical knowledge, a certain stage of +development must have been reached at a very early day. Even animals +pick and choose among the vegetables about them, and at times seek out +certain herbs quite different from their ordinary food, practising a +sort of instinctive therapeutics. The cat's fondness for catnip is +a case in point. The most primitive man, then, must have inherited a +racial or instinctive knowledge of the medicinal effects of certain +herbs; in particular he must have had such elementary knowledge of +toxicology as would enable him to avoid eating certain poisonous +berries. Perhaps, indeed, we are placing the effect before the cause +to some extent; for, after all, the animal system possesses marvellous +powers of adaption, and there is perhaps hardly any poisonous vegetable +which man might not have learned to eat without deleterious effect, +provided the experiment were made gradually. To a certain extent, then, +the observed poisonous effects of numerous plants upon the human system +are to be explained by the fact that our ancestors have avoided this +particular vegetable. Certain fruits and berries might have come to have +been a part of man's diet, had they grown in the regions he inhabited +at an early day, which now are poisonous to his system. This thought, +however, carries us too far afield. For practical purposes, it suffices +that certain roots, leaves, and fruits possess principles that are +poisonous to the human system, and that unless man had learned in some +way to avoid these, our race must have come to disaster. In point of +fact, he did learn to avoid them; and such evidence implied, as has been +said, an elementary knowledge of toxicology. + +Coupled with this knowledge of things dangerous to the human system, +there must have grown up, at a very early day, a belief in the remedial +character of various vegetables as agents to combat disease. Here, +of course, was a rudimentary therapeutics, a crude principle of an +empirical art of medicine. As just suggested, the lower order of animals +have an instinctive knowledge that enables them to seek out remedial +herbs (though we probably exaggerate the extent of this instinctive +knowledge); and if this be true, man must have inherited from his +prehuman ancestors this instinct along with the others. That he extended +this knowledge through observation and practice, and came early to make +extensive use of drugs in the treatment of disease, is placed beyond +cavil through the observation of the various existing barbaric tribes, +nearly all of whom practice elaborate systems of therapeutics. We shall +have occasion to see that even within historic times the particular +therapeutic measures employed were often crude, and, as we are +accustomed to say, unscientific; but even the crudest of them are really +based upon scientific principles, inasmuch as their application implies +the deduction of principles of action from previous observations. +Certain drugs are applied to appease certain symptoms of disease because +in the belief of the medicine-man such drugs have proved beneficial in +previous similar cases. + +All this, however, implies an appreciation of the fact that man is +subject to "natural" diseases, and that if these diseases are not +combated, death may result. But it should be understood that the +earliest man probably had no such conception as this. Throughout all the +ages of early development, what we call "natural" disease and "natural" +death meant the onslaught of a tangible enemy. A study of this question +leads us to some very curious inferences. The more we look into the +matter the more the thought forces itself home to us that the idea +of natural death, as we now conceive it, came to primitive man as +a relatively late scientific induction. This thought seems almost +startling, so axiomatic has the conception "man is mortal" come to +appear. Yet a study of the ideas of existing savages, combined with +our knowledge of the point of view from which historical peoples regard +disease, make it more probable that the primitive conception of human +life did not include the idea of necessary death. We are told that +the Australian savage who falls from a tree and breaks his neck is not +regarded as having met a natural death, but as having been the victim of +the magical practices of the "medicine-man" of some neighboring tribe. +Similarly, we shall find that the Egyptian and the Babylonian of the +early historical period conceived illness as being almost invariably +the result of the machinations of an enemy. One need but recall the +superstitious observances of the Middle Ages, and the yet more recent +belief in witchcraft, to realize how generally disease has been +personified as a malicious agent invoked by an unfriendly mind. Indeed, +the phraseology of our present-day speech is still reminiscent of this; +as when, for example, we speak of an "attack of fever," and the like. + +When, following out this idea, we picture to ourselves the conditions +under which primitive man lived, it will be evident at once how +relatively infrequent must have been his observation of what we usually +term natural death. His world was a world of strife; he lived by the +chase; he saw animals kill one another; he witnessed the death of his +own fellows at the hands of enemies. Naturally enough, then, when a +member of his family was "struck down" by invisible agents, he ascribed +this death also to violence, even though the offensive agent was +concealed. Moreover, having very little idea of the lapse of +time--being quite unaccustomed, that is, to reckon events from any fixed +era--primitive man cannot have gained at once a clear conception of age +as applied to his fellows. Until a relatively late stage of development +made tribal life possible, it cannot have been usual for man to have +knowledge of his grandparents; as a rule he did not know his own parents +after he had passed the adolescent stage and had been turned out upon +the world to care for himself. If, then, certain of his fellow-beings +showed those evidences of infirmity which we ascribe to age, it did not +necessarily follow that he saw any association between such infirmities +and the length of time which those persons had lived. The very fact that +some barbaric nations retain the custom of killing the aged and infirm, +in itself suggests the possibility that this custom arose before a clear +conception had been attained that such drags upon the community would be +removed presently in the natural order of things. To a person who had +no clear conception of the lapse of time and no preconception as to +the limited period of man's life, the infirmities of age might very +naturally be ascribed to the repeated attacks of those inimical powers +which were understood sooner or later to carry off most members of +the race. And coupled with this thought would go the conception that +inasmuch as some people through luck had escaped the vengeance of all +their enemies for long periods, these same individuals might continue +to escape for indefinite periods of the future. There were no written +records to tell primeval man of events of long ago. He lived in the +present, and his sweep of ideas scarcely carried him back beyond +the limits of his individual memory. But memory is observed to be +fallacious. It must early have been noted that some people recalled +events which other participants in them had quite forgotten, and it may +readily enough have been inferred that those members of the tribe who +spoke of events which others could not recall were merely the ones who +were gifted with the best memories. If these reached a period when their +memories became vague, it did not follow that their recollections +had carried them back to the beginnings of their lives. Indeed, it is +contrary to all experience to believe that any man remembers all +the things he has once known, and the observed fallaciousness and +evanescence of memory would thus tend to substantiate rather than to +controvert the idea that various members of a tribe had been alive for +an indefinite period. + +Without further elaborating the argument, it seems a justifiable +inference that the first conception primitive man would have of his +own life would not include the thought of natural death, but would, +conversely, connote the vague conception of endless life. Our +own ancestors, a few generations removed, had not got rid of this +conception, as the perpetual quest of the spring of eternal youth amply +testifies. A naturalist of our own day has suggested that perhaps birds +never die except by violence. The thought, then, that man has a term of +years beyond which "in the nature of things," as the saying goes, he +may not live, would have dawned but gradually upon the developing +intelligence of successive generations of men; and we cannot feel +sure that he would fully have grasped the conception of a "natural" +termination of human life until he had shaken himself free from the idea +that disease is always the result of the magic practice of an enemy. Our +observation of historical man in antiquity makes it somewhat doubtful +whether this conception had been attained before the close of the +prehistoric period. If it had, this conception of the mortality of man +was one of the most striking scientific inductions to which prehistoric +man attained. Incidentally, it may be noted that the conception of +eternal life for the human body being a more primitive idea than the +conception of natural death, the idea of the immortality of the spirit +would be the most natural of conceptions. The immortal spirit, indeed, +would be but a correlative of the immortal body, and the idea which we +shall see prevalent among the Egyptians that the soul persists only +as long as the body is intact--the idea upon which the practice of +mummifying the dead depended--finds a ready explanation. But this phase +of the subject carries us somewhat afield. For our present purpose it +suffices to have pointed out that the conception of man's mortality--a +conception which now seems of all others the most natural and +"innate"--was in all probability a relatively late scientific induction +of our primitive ancestors. + +5. Turning from the consideration of the body to its mental complement, +we are forced to admit that here, also, our primitive man must have +made certain elementary observations that underlie such sciences as +psychology, mathematics, and political economy. The elementary emotions +associated with hunger and with satiety, with love and with hatred, must +have forced themselves upon the earliest intelligence that reached the +plane of conscious self-observation. The capacity to count, at least +to the number four or five, is within the range of even animal +intelligence. Certain savages have gone scarcely farther than this; +but our primeval ancestor, who was forging on towards civilization, had +learned to count his fingers and toes, and to number objects about him +by fives and tens in consequence, before he passed beyond the plane of +numerous existing barbarians. How much beyond this he had gone we +need not attempt to inquire; but the relatively high development of +mathematics in the early historical period suggests that primeval man +had attained a not inconsiderable knowledge of numbers. The humdrum +vocation of looking after a numerous progeny must have taught the +mother the rudiments of addition and subtraction; and the elements of +multiplication and division are implied in the capacity to carry on +even the rudest form of barter, such as the various tribes must have +practised from an early day. + +As to political ideas, even the crudest tribal life was based on +certain conceptions of ownership, at least of tribal ownership, and the +application of the principle of likeness and difference to which we have +already referred. Each tribe, of course, differed in some regard from +other tribes, and the recognition of these differences implied in +itself a political classification. A certain tribe took possession of a +particular hunting-ground, which became, for the time being, its home, +and over which it came to exercise certain rights. An invasion of this +territory by another tribe might lead to war, and the banding together +of the members of the tribe to repel the invader implied both a +recognition of communal unity and a species of prejudice in favor of +that community that constituted a primitive patriotism. But this unity +of action in opposing another tribe would not prevent a certain rivalry +of interest between the members of the same tribe, which would show +itself more and more prominently as the tribe increased in size. The +association of two or more persons implies, always, the ascendency of +some and the subordination of others. Leadership and subordination are +necessary correlatives of difference of physical and mental endowment, +and rivalry between leaders would inevitably lead to the formation of +primitive political parties. With the ultimate success and ascendency +of one leader, who secures either absolute power or power modified in +accordance with the advice of subordinate leaders, we have the germs of +an elaborate political system--an embryo science of government. + +Meanwhile, the very existence of such a community implies the +recognition on the part of its members of certain individual rights, +the recognition of which is essential to communal harmony. The right of +individual ownership of the various articles and implements of every-day +life must be recognized, or all harmony would be at an end. Certain +rules of justice--primitive laws--must, by common consent, give +protection to the weakest members of the community. Here are the +rudiments of a system of ethics. It may seem anomalous to speak of this +primitive morality, this early recognition of the principles of right +and wrong, as having any relation to science. Yet, rightly considered, +there is no incongruity in such a citation. There cannot well be a doubt +that the adoption of those broad principles of right and wrong which +underlie the entire structure of modern civilization was due to +scientific induction,--in other words, to the belief, based on +observation and experience, that the principles implied were essential +to communal progress. He who has scanned the pageant of history knows +how often these principles seem to be absent in the intercourse of men +and nations. Yet the ideal is always there as a standard by which all +deeds are judged. + + +It would appear, then, that the entire superstructure of later science +had its foundation in the knowledge and practice of prehistoric man. The +civilization of the historical period could not have advanced as it has +had there not been countless generations of culture back of it. The new +principles of science could not have been evolved had there not +been great basal principles which ages of unconscious experiment had +impressed upon the mind of our race. Due meed of praise must be given, +then, to our primitive ancestor for his scientific accomplishments; but +justice demands that we should look a little farther and consider the +reverse side of the picture. We have had to do, thus far, chiefly +with the positive side of accomplishment. We have pointed out what our +primitive ancestor knew, intimating, perhaps, the limitations of his +knowledge; but we have had little to say of one all-important feature +of his scientific theorizing. The feature in question is based on the +highly scientific desire and propensity to find explanations for the +phenomena of nature. Without such desire no progress could be made. It +is, as we have seen, the generalizing from experience that constitutes +real scientific progress; and yet, just as most other good things can +be overdone, this scientific propensity may be carried to a disastrous +excess. + +Primeval man did not escape this danger. He observed, he reasoned, +he found explanations; but he did not always discriminate as to the +logicality of his reasonings. He failed to recognize the limitations of +his knowledge. The observed uniformity in the sequence of certain events +impressed on his mind the idea of cause and effect. Proximate causes +known, he sought remoter causes; childlike, his inquiring mind was +always asking, Why? and, childlike, he demanded an explicit answer. If +the forces of nature seemed to combat him, if wind and rain opposed his +progress and thunder and lightning seemed to menace his existence, he +was led irrevocably to think of those human foes who warred with +him, and to see, back of the warfare of the elements, an inscrutable +malevolent intelligence which took this method to express its +displeasure. But every other line of scientific observation leads +equally, following back a sequence of events, to seemingly causeless +beginnings. Modern science can explain the lightning, as it can explain +a great number of the mysteries which the primeval intelligence could +not penetrate. But the primordial man could not wait for the revelations +of scientific investigation: he must vault at once to a final solution +of all scientific problems. He found his solution by peopling the world +with invisible forces, anthropomorphic in their conception, like himself +in their thought and action, differing only in the limitations of their +powers. His own dream existence gave him seeming proof of the existence +of an alter ego, a spiritual portion of himself that could dissever +itself from his body and wander at will; his scientific inductions +seemed to tell him of a world of invisible beings, capable of +influencing him for good or ill. From the scientific exercise of his +faculties he evolved the all-encompassing generalizations of invisible +and all-powerful causes back of the phenomena of nature. These +generalizations, early developed and seemingly supported by the +observations of countless generations, came to be among the most +firmly established scientific inductions of our primeval ancestor. +They obtained a hold upon the mentality of our race that led subsequent +generations to think of them, sometimes to speak of them, as "innate" +ideas. The observations upon which they were based are now, for the most +part, susceptible of other interpretations; but the old interpretations +have precedent and prejudice back of them, and they represent ideas +that are more difficult than almost any others to eradicate. Always, +and everywhere, superstitions based upon unwarranted early scientific +deductions have been the most implacable foes to the progress of +science. Men have built systems of philosophy around their conception of +anthropomorphic deities; they have linked to these systems of philosophy +the allied conception of the immutability of man's spirit, and they have +asked that scientific progress should stop short at the brink of these +systems of philosophy and accept their dictates as final. Yet there is +not to-day in existence, and there never has been, one jot of scientific +evidence for the existence of these intangible anthropomorphic powers +back of nature that is not susceptible of scientific challenge and +of more logical interpretation. In despite of which the superstitious +beliefs are still as firmly fixed in the minds of a large majority of +our race as they were in the mind of our prehistoric ancestor. The fact +of this baleful heritage must not be forgotten in estimating the debt of +gratitude which historic man owes to his barbaric predecessor. + + + + +II. EGYPTIAN SCIENCE + +In the previous chapter we have purposely refrained from referring to +any particular tribe or race of historical man. Now, however, we are +at the beginnings of national existence, and we have to consider the +accomplishments of an individual race; or rather, perhaps, of two or +more races that occupied successively the same geographical territory. +But even now our studies must for a time remain very general; we shall +see little or nothing of the deeds of individual scientists in the +course of our study of Egyptian culture. We are still, it must be +understood, at the beginnings of history; indeed, we must first bridge +over the gap from the prehistoric before we may find ourselves fairly on +the line of march of historical science. + +At the very outset we may well ask what constitutes the distinction +between prehistoric and historic epochs--a distinction which has been +constantly implied in much that we have said. The reply savors somewhat +of vagueness. It is a distinction having to do, not so much with facts +of human progress as with our interpretation of these facts. When we +speak of the dawn of history we must not be understood to imply that, at +the period in question, there was any sudden change in the intellectual +status of the human race or in the status of any individual tribe or +nation of men. What we mean is that modern knowledge has penetrated the +mists of the past for the period we term historical with something more +of clearness and precision than it has been able to bring to bear upon +yet earlier periods. New accessions of knowledge may thus shift from +time to time the bounds of the so-called historical period. The clearest +illustration of this is furnished by our interpretation of Egyptian +history. Until recently the biblical records of the Hebrew captivity or +service, together with the similar account of Josephus, furnished about +all that was known of Egyptian history even of so comparatively recent +a time as that of Ramses II. (fifteenth century B.C.), and from that +period on there was almost a complete gap until the story was taken +up by the Greek historians Herodotus and Diodorus. It is true that +the king-lists of the Alexandrian historian, Manetho, were all along +accessible in somewhat garbled copies. But at best they seemed to supply +unintelligible lists of names and dates which no one was disposed +to take seriously. That they were, broadly speaking, true historical +records, and most important historical records at that, was not +recognized by modern scholars until fresh light had been thrown on the +subject from altogether new sources. + +These new sources of knowledge of ancient history demand a moment's +consideration. They are all-important because they have been the means +of extending the historical period of Egyptian history (using the word +history in the way just explained) by three or four thousand years. As +just suggested, that historical period carried the scholarship of the +early nineteenth century scarcely beyond the fifteenth century B.C., but +to-day's vision extends with tolerable clearness to about the middle +of the fifth millennium B.C. This change has been brought about chiefly +through study of the Egyptian hieroglyphics. These hieroglyphics +constitute, as we now know, a highly developed system of writing; a +system that was practised for some thousands of years, but which fell +utterly into disuse in the later Roman period, and the knowledge of +which passed absolutely from the mind of man. For about two thousand +years no one was able to read, with any degree of explicitness, a single +character of this strange script, and the idea became prevalent that +it did not constitute a real system of writing, but only a more or less +barbaric system of religious symbolism. The falsity of this view was +shown early in the nineteenth century when Dr. Thomas Young was led, +through study of the famous trilingual inscription of the Rosetta stone, +to make the first successful attempt at clearing up the mysteries of the +hieroglyphics. + +This is not the place to tell the story of his fascinating discoveries +and those of his successors. That story belongs to nineteenth-century +science, not to the science of the Egyptians. Suffice it here that Young +gained the first clew to a few of the phonetic values of the Egyptian +symbols, and that the work of discovery was carried on and vastly +extended by the Frenchman Champollion, a little later, with the result +that the firm foundations of the modern science of Egyptology were laid. +Subsequently such students as Rosellini the Italian, Lepsius the German, +and Wilkinson the Englishman, entered the field, which in due course +was cultivated by De Rouge in France and Birch in England, and by +such distinguished latter-day workers as Chabas, Mariette, Maspero, +Amelineau, and De Morgan among the Frenchmen; Professor Petrie and Dr. +Budge in England; and Brugsch Pasha and Professor Erman in Germany, not +to mention a large coterie of somewhat less familiar names. These men +working, some of them in the field of practical exploration, some as +students of the Egyptian language and writing, have restored to us a +tolerably precise knowledge of the history of Egypt from the time of the +first historical king, Mena, whose date is placed at about the middle +of the fifth century B.C. We know not merely the names of most of the +subsequent rulers, but some thing of the deeds of many of them; +and, what is vastly more important, we know, thanks to the modern +interpretation of the old literature, many things concerning the life +of the people, and in particular concerning their highest culture, their +methods of thought, and their scientific attainments, which might well +have been supposed to be past finding out. Nor has modern investigation +halted with the time of the first kings; the recent explorations of such +archaeologists as Amelineau, De Morgan, and Petrie have brought to light +numerous remains of what is now spoken of as the predynastic period--a +period when the inhabitants of the Nile Valley used implements of +chipped stone, when their pottery was made without the use of the +potter's wheel, and when they buried their dead in curiously cramped +attitudes without attempt at mummification. These aboriginal inhabitants +of Egypt cannot perhaps with strict propriety be spoken of as living +within the historical period, since we cannot date their relics with any +accuracy. But they give us glimpses of the early stages of civilization +upon which the Egyptians of the dynastic period were to advance. + +It is held that the nascent civilization of these Egyptians of the +Neolithic, or late Stone Age, was overthrown by the invading hosts of a +more highly civilized race which probably came from the East, and which +may have been of a Semitic stock. The presumption is that this invading +people brought with it a knowledge of the arts of war and peace, +developed or adopted in its old home. The introduction of these arts +served to bridge somewhat suddenly, so far as Egypt is concerned, that +gap between the prehistoric and the historic stage of culture to which +we have all along referred. The essential structure of that bridge, +let it now be clearly understood, consisted of a single element. That +element is the capacity to make written records: a knowledge of the art +of writing. Clearly understood, it is this element of knowledge that +forms the line bounding the historical period. Numberless mementos are +in existence that tell of the intellectual activities of prehistoric +man; such mementos as flint implements, pieces of pottery, and fragments +of bone, inscribed with pictures that may fairly be spoken of as works +of art; but so long as no written word accompanies these records, so +long as no name of king or scribe comes down to us, we feel that these +records belong to the domain of archaeology rather than to that of +history. Yet it must be understood all along that these two domains +shade one into the other and, it has already been urged, that the +distinction between them is one that pertains rather to modern +scholarship than to the development of civilization itself. Bearing this +distinction still in mind, and recalling that the historical period, +which is to be the field of our observation throughout the rest of our +studies, extends for Egypt well back into the fifth millennium B.C., let +us briefly review the practical phases of that civilization to which the +Egyptian had attained before the beginning of the dynastic period. Since +theoretical science is everywhere linked with the mechanical arts, this +survey will give us a clear comprehension of the field that lies open +for the progress of science in the long stages of historical time upon +which we are just entering. + +We may pass over such rudimentary advances in the direction of +civilization as are implied in the use of articulate language, the +application of fire to the uses of man, and the systematic making of +dwellings of one sort or another, since all of these are stages of +progress that were reached very early in the prehistoric period. +What more directly concerns us is to note that a really high stage of +mechanical development had been reached before the dawnings of Egyptian +history proper. All manner of household utensils were employed; the +potter's wheel aided in the construction of a great variety of earthen +vessels; weaving had become a fine art, and weapons of bronze, including +axes, spears, knives, and arrow-heads, were in constant use. Animals had +long been domesticated, in particular the dog, the cat, and the ox; +the horse was introduced later from the East. The practical arts of +agriculture were practised almost as they are at the present day in +Egypt, there being, of course, the same dependence then as now upon the +inundations of the Nile. + +As to government, the Egyptian of the first dynasty regarded his king +as a demi-god to be actually deified after his death, and this point of +view was not changed throughout the stages of later Egyptian history. In +point of art, marvellous advances upon the skill of the prehistoric +man had been made, probably in part under Asiatic influences, and that +unique style of stilted yet expressive drawing had come into vogue, +which was to be remembered in after times as typically Egyptian. More +important than all else, our Egyptian of the earliest historical period +was in possession of the art of writing. He had begun to make those +specific records which were impossible to the man of the Stone Age, and +thus he had entered fully upon the way of historical progress which, as +already pointed out, has its very foundation in written records. From +now on the deeds of individual kings could find specific record. It +began to be possible to fix the chronology of remote events with some +accuracy; and with this same fixing of chronologies came the advent of +true history. The period which precedes what is usually spoken of as +the first dynasty in Egypt is one into which the present-day searcher +is still able to see but darkly. The evidence seems to suggest than an +invasion of relatively cultured people from the East overthrew, and in +time supplanted, the Neolithic civilization of the Nile Valley. It is +impossible to date this invasion accurately, but it cannot well have +been later than the year 5000 B.C., and it may have been a great many +centuries earlier than this. Be the exact dates what they may, we find +the Egyptian of the fifth millennium B.C. in full possession of a highly +organized civilization. + +All subsequent ages have marvelled at the pyramids, some of which date +from about the year 4000 B.C., though we may note in passing that these +dates must not be taken too literally. The chronology of ancient Egypt +cannot as yet be fixed with exact accuracy, but the disagreements +between the various students of the subject need give us little concern. +For our present purpose it does not in the least matter whether the +pyramids were built three thousand or four thousand years before the +beginning of our era. It suffices that they date back to a period long +antecedent to the beginnings of civilization in Western Europe. They +prove that the Egyptian of that early day had attained a knowledge of +practical mechanics which, even from the twentieth-century point of +view, is not to be spoken of lightly. It has sometimes been suggested +that these mighty pyramids, built as they are of great blocks of stone, +speak for an almost miraculous knowledge on the part of their builders; +but a saner view of the conditions gives no warrant for this thought. +Diodoras, the Sicilian, in his famous World's History, written about +the beginning of our era, explains the building of the pyramids by +suggesting that great quantities of earth were piled against the side +of the rising structure to form an inclined plane up which the blocks +of stone were dragged. He gives us certain figures, based, doubtless, +on reports made to him by Egyptian priests, who in turn drew upon the +traditions of their country, perhaps even upon written records no +longer preserved. He says that one hundred and twenty thousand men +were employed in the construction of the largest pyramid, and that, +notwithstanding the size of this host of workers, the task occupied +twenty years. We must not place too much dependence upon such figures as +these, for the ancient historians are notoriously given to exaggeration +in recording numbers; yet we need not doubt that the report given by +Diodorus is substantially accurate in its main outlines as to the method +through which the pyramids were constructed. A host of men putting their +added weight and strength to the task, with the aid of ropes, pulleys, +rollers, and levers, and utilizing the principle of the inclined plane, +could undoubtedly move and elevate and place in position the +largest blocks that enter into the pyramids or--what seems even more +wonderful--the most gigantic obelisks, without the aid of any other +kind of mechanism or of any more occult power. The same hands could, as +Diodorus suggests, remove all trace of the debris of construction and +leave the pyramids and obelisks standing in weird isolation, as if +sprung into being through a miracle. + + +ASTRONOMICAL SCIENCE + +It has been necessary to bear in mind these phases of practical +civilization because much that we know of the purely scientific +attainments of the Egyptians is based upon modern observation of their +pyramids and temples. It was early observed, for example, that the +pyramids are obviously oriented as regards the direction in which they +face, in strict accordance with some astronomical principle. Early in +the nineteenth century the Frenchman Biot made interesting studies in +regard to this subject, and a hundred years later, in our own time, Sir +Joseph Norman Lockyer, following up the work of various intermediary +observers, has given the subject much attention, making it the central +theme of his work on The Dawn of Astronomy.(1) Lockyer's researches +make it clear that in the main the temples of Egypt were oriented with +reference to the point at which the sun rises on the day of the summer +solstice. The time of the solstice had peculiar interest for the +Egyptians, because it corresponded rather closely with the time of the +rising of the Nile. The floods of that river appear with very great +regularity; the on-rushing tide reaches the region of Heliopolis and +Memphis almost precisely on the day of the summer solstice. The +time varies at different stages of the river's course, but as the +civilization of the early dynasties centred at Memphis, observations +made at this place had widest vogue. + +Considering the all-essential character of the Nile floods-without which +civilization would be impossible in Egypt--it is not strange that the +time of their appearance should be taken as marking the beginning of a +new year. The fact that their coming coincides with the solstice makes +such a division of the calendar perfectly natural. In point of fact, +from the earliest periods of which records have come down to us, the new +year of the Egyptians dates from the summer solstice. It is certain that +from the earliest historical periods the Egyptians were aware of the +approximate length of the year. It would be strange were it otherwise, +considering the ease with which a record of days could be kept from Nile +flood to Nile flood, or from solstice to solstice. But this, of course, +applies only to an approximate count. There is some reason to believe +that in the earliest period the Egyptians made this count only 360 days. +The fact that their year was divided into twelve months of thirty days +each lends color to this belief; but, in any event, the mistake was +discovered in due time and a partial remedy was applied through the +interpolation of a "little month" of five days between the end of the +twelfth month and the new year. This nearly but not quite remedied +the matter. What it obviously failed to do was to take account of that +additional quarter of a day which really rounds out the actual year. + +It would have been a vastly convenient thing for humanity had it chanced +that the earth had so accommodated its rotary motion with its speed +of transit about the sun as to make its annual flight in precisely 360 +days. Twelve lunar months of thirty days each would then have coincided +exactly with the solar year, and most of the complexities of the +calendar, which have so puzzled historical students, would have been +avoided; but, on the other hand, perhaps this very simplicity would +have proved detrimental to astronomical science by preventing men from +searching the heavens as carefully as they have done. Be that as it may, +the complexity exists. The actual year of three hundred and sixty-five +and (about) one-quarter days cannot be divided evenly into months, +and some such expedient as the intercalation of days here and there is +essential, else the calendar will become absolutely out of harmony with +the seasons. + +In the case of the Egyptians, the attempt at adjustment was made, as +just noted, by the introduction of the five days, constituting what the +Egyptians themselves termed "the five days over and above the year." +These so-called epagomenal days were undoubtedly introduced at a very +early period. Maspero holds that they were in use before the first +Thinite dynasty, citing in evidence the fact that the legend of Osiris +explains these days as having been created by the god Thot in order +to permit Nuit to give birth to all her children; this expedient being +necessary to overcome a ban which had been pronounced against Nuit, +according to which she could not give birth to children on any day of +the year. But, of course, the five additional days do not suffice fully +to rectify the calendar. There remains the additional quarter of a day +to be accounted for. This, of course, amounts to a full day every fourth +year. We shall see that later Alexandrian science hit upon the expedient +of adding a day to every fourth year; an expedient which the Julian +calendar adopted and which still gives us our familiar leap-year. But, +unfortunately, the ancient Egyptian failed to recognize the need of +this additional day, or if he did recognize it he failed to act on +his knowledge, and so it happened that, starting somewhere back in the +remote past with a new year's day that coincided with the inundation of +the Nile, there was a constantly shifting maladjustment of calendar and +seasons as time went on. + +The Egyptian seasons, it should be explained, were three in number: the +season of the inundation, the season of the seed-time, and the season +of the harvest; each season being, of course, four months in extent. +Originally, as just mentioned, the season of the inundations began and +coincided with the actual time of inundation. The more precise fixing of +new year's day was accomplished through observation of the time of +the so-called heliacal rising of the dog-star, Sirius, which bore the +Egyptian name Sothis. It chances that, as viewed from about the region +of Heliopolis, the sun at the time of the summer solstice occupies an +apparent position in the heavens close to the dog-star. Now, as is well +known, the Egyptians, seeing divinity back of almost every phenomenon +of nature, very naturally paid particular reverence to so obviously +influential a personage as the sun-god. In particular they thought it +fitting to do homage to him just as he was starting out on his tour of +Egypt in the morning; and that they might know the precise moment of his +coming, the Egyptian astronomer priests, perched on the hill-tops near +their temples, were wont to scan the eastern horizon with reference +to some star which had been observed to precede the solar luminary. +Of course the precession of the equinoxes, due to that axial wobble in +which our clumsy earth indulges, would change the apparent position of +the fixed stars in reference to the sun, so that the same star could not +do service as heliacal messenger indefinitely; but, on the other hand, +these changes are so slow that observations by many generations of +astronomers would be required to detect the shifting. It is believed +by Lockyer, though the evidence is not quite demonstrative, that the +astronomical observations of the Egyptians date back to a period when +Sothis, the dog-star, was not in close association with the sun on the +morning of the summer solstice. Yet, according to the calculations of +Biot, the heliacal rising of Sothis at the solstice was noted as early +as the year 3285 B.C., and it is certain that this star continued +throughout subsequent centuries to keep this position of peculiar +prestige. Hence it was that Sothis came to be associated with Isis, one +of the most important divinities of Egypt, and that the day in which +Sothis was first visible in the morning sky marked the beginning of +the new year; that day coinciding, as already noted, with the summer +solstice and with the beginning of the Nile flow. + +But now for the difficulties introduced by that unreckoned quarter of +a day. Obviously with a calendar of 365 days only, at the end of four +years, the calendar year, or vague year, as the Egyptians came to call +it, had gained by one full day upon the actual solar year--that is to +say, the heliacal rising of Sothis, the dog-star, would not occur on +new year's day of the faulty calendar, but a day later. And with each +succeeding period of four years the day of heliacal rising, which marked +the true beginning of the year--and which still, of course, coincided +with the inundation--would have fallen another day behind the calendar. +In the course of 120 years an entire month would be lost; and in 480 +years so great would become the shifting that the seasons would be +altogether misplaced; the actual time of inundations corresponding with +what the calendar registered as the seed-time, and the actual seed-time +in turn corresponding with the harvest-time of the calendar. + +At first thought this seems very awkward and confusing, but in all +probability the effects were by no means so much so in actual practice. +We need go no farther than to our own experience to know that the names +of seasons, as of months and days, come to have in the minds of most of +us a purely conventional significance. Few of us stop to give a thought +to the meaning of the words January, February, etc., except as they +connote certain climatic conditions. If, then, our own calendar were +so defective that in the course of 120 years the month of February had +shifted back to occupy the position of the original January, the change +would have been so gradual, covering the period of two life-times or +of four or five average generations, that it might well escape general +observation. + +Each succeeding generation of Egyptians, then, may not improbably have +associated the names of the seasons with the contemporary climatic +conditions, troubling themselves little with the thought that in an +earlier age the climatic conditions for each period of the calendar were +quite different. We cannot well suppose, however, that the astronomer +priests were oblivious to the true state of things. Upon them devolved +the duty of predicting the time of the Nile flood; a duty they were +enabled to perform without difficulty through observation of the rising +of the solstitial sun and its Sothic messenger. To these observers it +must finally have been apparent that the shifting of the seasons was +at the rate of one day in four years; this known, it required no great +mathematical skill to compute that this shifting would finally effect a +complete circuit of the calendar, so that after (4 X 365 =) 1460 +years the first day of the calendar year would again coincide with the +heliacal rising of Sothis and with the coming of the Nile flood. In +other words, 1461 vague years or Egyptian calendar years Of 365 days +each correspond to 1460 actual solar years of 365 1/4 days each. This +period, measured thus by the heliacal rising of Sothis, is spoken of as +the Sothic cycle. + +To us who are trained from childhood to understand that the year +consists of (approximately) 365 1/4 days, and to know that the calendar +may be regulated approximately by the introduction of an extra day every +fourth year, this recognition of the Sothic cycle seems simple enough. +Yet if the average man of us will reflect how little he knows, of his +own knowledge, of the exact length of the year, it will soon become +evident that the appreciation of the faults of the calendar and the +knowledge of its periodical adjustment constituted a relatively +high development of scientific knowledge on the part of the Egyptian +astronomer. It may be added that various efforts to reform the calendar +were made by the ancient Egyptians, but that they cannot be credited +with a satisfactory solution of the problem; for, of course, the +Alexandrian scientists of the Ptolemaic period (whose work we shall have +occasion to review presently) were not Egyptians in any proper sense of +the word, but Greeks. + +Since so much of the time of the astronomer priests was devoted to +observation of the heavenly bodies, it is not surprising that they +should have mapped out the apparent course of the moon and the visible +planets in their nightly tour of the heavens, and that they should have +divided the stars of the firmament into more or less arbitrary groups +or constellations. That they did so is evidenced by various sculptured +representations of constellations corresponding to signs of the +zodiac which still ornament the ceilings of various ancient temples. +Unfortunately the decorative sense, which was always predominant with +the Egyptian sculptor, led him to take various liberties with the +distribution of figures in these representations of the constellations, +so that the inferences drawn from them as to the exact map of the +heavens as the Egyptians conceived it cannot be fully relied upon. It +appears, however, that the Egyptian astronomer divided the zodiac +into twenty-four decani, or constellations. The arbitrary groupings +of figures, with the aid of which these are delineated, bear a close +resemblance to the equally arbitrary outlines which we are still +accustomed to use for the same purpose. + + +IDEAS OF COSMOLOGY + +In viewing this astronomical system of the Egyptians one cannot avoid +the question as to just what interpretation was placed upon it as +regards the actual mechanical structure of the universe. A proximal +answer to the question is supplied us with a good deal of clearness. +It appears that the Egyptian conceived the sky as a sort of tangible or +material roof placed above the world, and supported at each of its four +corners by a column or pillar, which was later on conceived as a great +mountain. The earth itself was conceived to be a rectangular box, longer +from north to south than from east to west; the upper surface of this +box, upon which man lived, being slightly concave and having, of course, +the valley of the Nile as its centre. The pillars of support were +situated at the points of the compass; the northern one being located +beyond the Mediterranean Sea; the southern one away beyond the habitable +regions towards the source of the Nile, and the eastern and western ones +in equally inaccessible regions. Circling about the southern side +of the world was a great river suspended in mid-air on something +comparable to mountain cliffs; on which river the sun-god made his daily +course in a boat, fighting day by day his ever-recurring battle against +Set, the demon of darkness. The wide channel of this river enabled the +sun-god to alter his course from time to time, as he is observed to do; +in winter directing his bark towards the farther bank of the channel; +in summer gliding close to the nearer bank. As to the stars, they were +similar lights, suspended from the vault of the heaven; but just how +their observed motion of translation across the heavens was explained +is not apparent. It is more than probable that no one explanation was, +universally accepted. + +In explaining the origin of this mechanism of the heavens, the Egyptian +imagination ran riot. Each separate part of Egypt had its own hierarchy +of gods, and more or less its own explanations of cosmogony. There does +not appear to have been any one central story of creation that found +universal acceptance, any more than there was one specific deity +everywhere recognized as supreme among the gods. Perhaps the most +interesting of the cosmogonic myths was that which conceived that Nuit, +the goddess of night, had been torn from the arms of her husband, Sibu +the earth-god, and elevated to the sky despite her protests and her +husband's struggles, there to remain supported by her four limbs, which +became metamorphosed into the pillars, or mountains, already mentioned. +The forcible elevation of Nuit had been effected on the day of creation +by a new god, Shu, who came forth from the primeval waters. A +painting on the mummy case of one Betuhamon, now in the Turin Museum, +illustrates, in the graphic manner so characteristic of the Egyptians, +this act of creation. As Maspero(2) points out, the struggle of Sibu +resulted in contorted attitudes to which the irregularities of the +earth's surface are to be ascribed. + +In contemplating such a scheme of celestial mechanics as that just +outlined, one cannot avoid raising the question as to just the degree +of literalness which the Egyptians themselves put upon it. We know how +essentially eye-minded the Egyptian was, to use a modern psychological +phrase--that is to say, how essential to him it seemed that all his +conceptions should be visualized. The evidences of this are everywhere: +all his gods were made tangible; he believed in the immortality of +the soul, yet he could not conceive of such immortality except in +association with an immortal body; he must mummify the body of the dead, +else, as he firmly believed, the dissolution of the spirit would take +place along with the dissolution of the body itself. His world was +peopled everywhere with spirits, but they were spirits associated always +with corporeal bodies; his gods found lodgment in sun and moon and +stars; in earth and water; in the bodies of reptiles and birds and +mammals. He worshipped all of these things: the sun, the moon, water, +earth, the spirit of the Nile, the ibis, the cat, the ram, and apis the +bull; but, so far as we can judge, his imagination did not reach to the +idea of an absolutely incorporeal deity. Similarly his conception of +the mechanism of the heavens must be a tangibly mechanical one. He must +think of the starry firmament as a substantial entity which could not +defy the law of gravitation, and which, therefore, must have the same +manner of support as is required by the roof of a house or temple. We +know that this idea of the materiality of the firmament found elaborate +expression in those later cosmological guesses which were to dominate +the thought of Europe until the time of Newton. We need not doubt, +therefore, that for the Egyptian this solid vault of the heavens had a +very real existence. If now and then some dreamer conceived the great +bodies of the firmament as floating in a less material plenum--and such +iconoclastic dreamers there are in all ages--no record of his musings +has come down to us, and we must freely admit that if such thoughts +existed they were alien to the character of the Egyptian mind as a +whole. + +While the Egyptians conceived the heavenly bodies as the abiding-place +of various of their deities, it does not appear that they practised +astrology in the later acceptance of that word. This is the more +remarkable since the conception of lucky and unlucky days was carried +by the Egyptians to the extremes of absurdity. "One day was lucky +or unlucky," says Erman,(3) "according as a good or bad mythological +incident took place on that day. For instance, the 1st of Mechir, on +which day the sky was raised, and the 27th of Athyr, when Horus and, Set +concluded peace together and divided the world between them, were lucky +days; on the other hand, the 14th of Tybi, on which Isis and Nephthys +mourned for Osiris, was an unlucky day. With the unlucky days, which, +fortunately, were less in number than the lucky days, they distinguished +different degrees of ill-luck. Some were very unlucky, others only +threatened ill-luck, and many, like the 17th and the 27th Choiakh, were +partly good and partly bad according to the time of day. Lucky days +might, as a rule, be disregarded. At most it might be as well to visit +some specially renowned temple, or to 'celebrate a joyful day at home,' +but no particular precautions were really necessary; and, above all, +it was said, 'what thou also seest on the day is lucky.' It was quite +otherwise with the unlucky and dangerous days, which imposed so many +and such great limitations on people that those who wished to be prudent +were always obliged to bear them in mind when determining on any course +of action. Certain conditions were easy to carry out. Music and singing +were to be avoided on the 14th Tybi, the day of the mourning of Osiris, +and no one was allowed to wash on the 16th Tybi; whilst the name of Set +might not be pronounced on the 24th of Pharmuthi. Fish was forbidden on +certain days; and what was still more difficult in a country so rich +in mice, on the 12th of Tybi no mouse might be seen. The most tiresome +prohibitions, however, were those which occurred not infrequently, +namely, those concerning work and going out: for instance, four times in +Paophi the people had to 'do nothing at all,' and five times to sit +the whole day or half the day in the house; and the same rule had to be +observed each month. It was impossible to rejoice if a child was born on +the 23d of Thoth; the parents knew it could not live. Those born on the +20th of Choiakh would become blind, and those born on the 3d of Choiakh, +deaf." + + +CHARMS AND INCANTATIONS + +Where such conceptions as these pertained, it goes without saying that +charms and incantations intended to break the spell of the unlucky +omens were equally prevalent. Such incantations consisted usually of the +recitation of certain phrases based originally, it would appear, upon +incidents in the history of the gods. The words which the god had spoken +in connection with some lucky incident would, it was thought, prove +effective now in bringing good luck to the human supplicant--that is +to say, the magician hoped through repeating the words of the god to +exercise the magic power of the god. It was even possible, with the aid +of the magical observances, partly to balk fate itself. Thus the person +predestined through birth on an unlucky day to die of a serpent bite +might postpone the time of this fateful visitation to extreme old age. +The like uncertainty attached to those spells which one person was +supposed to be able to exercise over another. It was held, for example, +that if something belonging to an individual, such as a lock of hair +or a paring of the nails, could be secured and incorporated in a waxen +figure, this figure would be intimately associated with the personality +of that individual. An enemy might thus secure occult power over one; +any indignity practised upon the waxen figure would result in like +injury to its human prototype. If the figure were bruised or beaten, +some accident would overtake its double; if the image were placed over +a fire, the human being would fall into a fever, and so on. But, of +course, such mysterious evils as these would be met and combated by +equally mysterious processes; and so it was that the entire art of +medicine was closely linked with magical practices. It was not, indeed, +held, according to Maspero, that the magical spells of enemies were +the sole sources of human ailments, but one could never be sure to what +extent such spells entered into the affliction; and so closely were the +human activities associated in the mind of the Egyptian with one form or +another of occult influences that purely physical conditions were at a +discount. In the later times, at any rate, the physician was usually +a priest, and there was a close association between the material and +spiritual phases of therapeutics. Erman(4) tells us that the following +formula had to be recited at the preparation of all medicaments: "That +Isis might make free, make free. That Isis might make Horus free from +all evil that his brother Set had done to him when he slew his father, +Osiris. O Isis, great enchantress, free me, release me from all evil red +things, from the fever of the god, and the fever of the goddess, from +death and death from pain, and the pain which comes over me; as thou +hast freed, as thou hast released thy son Horus, whilst I enter into the +fire and come forth from the water," etc. Again, when the invalid took +the medicine, an incantation had to be said which began thus: "Come +remedy, come drive it out of my heart, out of these limbs strong in +magic power with the remedy." He adds: "There may have been a few +rationalists amongst the Egyptian doctors, for the number of magic +formulae varies much in the different books. The book that we +have specially taken for a foundation for this account of Egyptian +medicine--the great papyrus of the eighteenth dynasty edited by +Ebers(5)--contains, for instance, far fewer exorcisms than some later +writings with similar contents, probably because the doctor who compiled +this book of recipes from older sources had very little liking for +magic." + +It must be understood, however--indeed, what has just been said implies +as much--that the physician by no means relied upon incantations alone; +on the contrary, he equipped himself with an astonishing variety of +medicaments. He had a particular fondness for what the modern physician +speaks of as a "shot-gun" prescription--one containing a great variety +of ingredients. Not only did herbs of many kinds enter into this, but +such substances as lizard's blood, the teeth of swine, putrid meat, +the moisture from pigs' ears, boiled horn, and numerous other even more +repellent ingredients. Whoever is familiar with the formulae employed by +European physicians even so recently as the eighteenth century will note +a striking similarity here. Erman points out that the modern Egyptian +even of this day holds closely to many of the practices of his remote +ancestor. In particular, the efficacy of the beetle as a medicinal +agent has stood the test of ages of practice. "Against all kinds of +witchcraft," says an ancient formula, "a great scarabaeus beetle; cut +off his head and wings, boil him; put him in oil and lay him out; +then cook his head and wings, put them in snake fat, boil, and let the +patient drink the mixture." The modern Egyptian, says Erman, uses almost +precisely the same recipe, except that the snake fat is replaced by +modern oil. + +In evidence of the importance which was attached to practical medicine +in the Egypt of an early day, the names of several physicians have come +down to us from an age which has preserved very few names indeed, save +those of kings. In reference to this Erman says(6): "We still know +the names of some of the early body physicians of this time; +Sechmetna'eonch, 'chief physician of the Pharaoh,' and Nesmenan his +chief, the 'superintendent of the physicians of the Pharaoh.' The +priests also of the lioness-headed goddess Sechmet seem to have been +famed for their medical wisdom, whilst the son of this goddess, the +demi-god Imhotep, was in later times considered to be the creator of +medical knowledge. These ancient doctors of the New Empire do not seem +to have improved upon the older conceptions about the construction of +the human body." + +As to the actual scientific attainments of the Egyptian physician, it is +difficult to speak with precision. Despite the cumbersome formulae and +the grotesque incantations, we need not doubt that a certain practical +value attended his therapeutics. He practised almost pure empiricism, +however, and certainly it must have been almost impossible to determine +which ones, if any, of the numerous ingredients of the prescription had +real efficacy. + +The practical anatomical knowledge of the physician, there is every +reason to believe, was extremely limited. At first thought it might +seem that the practice of embalming would have led to the custom of +dissecting human bodies, and that the Egyptians, as a result of this, +would have excelled in the knowledge of anatomy. But the actual +results were rather the reverse of this. Embalming the dead, it must +be recalled, was a purely religious observance. It took place under the +superintendence of the priests, but so great was the reverence for the +human body that the priests themselves were not permitted to make the +abdominal incision which was a necessary preliminary of the process. +This incision, as we are informed by both Herodotus(7) and Diodorus(8), +was made by a special officer, whose status, if we may believe the +explicit statement of Diodorus, was quite comparable to that of the +modern hangman. The paraschistas, as he was called, having performed +his necessary but obnoxious function, with the aid of a sharp Ethiopian +stone, retired hastily, leaving the remaining processes to the priests. +These, however, confined their observations to the abdominal viscera; +under no consideration did they make other incisions in the body. It +follows, therefore, that their opportunity for anatomical observations +was most limited. + +Since even the necessary mutilation inflicted on the corpse was regarded +with such horror, it follows that anything in the way of dissection +for a less sacred purpose was absolutely prohibited. Probably the same +prohibition extended to a large number of animals, since most of these +were held sacred in one part of Egypt or another. Moreover, there is +nothing in what we know of the Egyptian mind to suggest the probability +that any Egyptian physician would make extensive anatomical observations +for the love of pure knowledge. All Egyptian science is eminently +practical. If we think of the Egyptian as mysterious, it is because +of the superstitious observances that we everywhere associate with his +daily acts; but these, as we have already tried to make clear, were +really based on scientific observations of a kind, and the attempt at +true inferences from these observations. But whether or not the Egyptian +physician desired anatomical knowledge, the results of his inquiries +were certainly most meagre. The essentials of his system had to do with +a series of vessels, alleged to be twenty-two or twenty-four in number, +which penetrated the head and were distributed in pairs to the various +members of the body, and which were vaguely thought of as carriers of +water, air, excretory fluids, etc. Yet back of this vagueness, as must +not be overlooked, there was an all-essential recognition of the heart +as the central vascular organ. The heart is called the beginning of all +the members. Its vessels, we are told, "lead to all the members; whether +the doctor lays his finger on the forehead, on the back of the head, on +the hands, on the place of the stomach (?), on the arms, or on the feet, +everywhere he meets with the heart, because its vessels lead to all +the members."(9) This recognition of the pulse must be credited to the +Egyptian physician as a piece of practical knowledge, in some measure +off-setting the vagueness of his anatomical theories. + + +ABSTRACT SCIENCE + +But, indeed, practical knowledge was, as has been said over and +over, the essential characteristic of Egyptian science. Yet another +illustration of this is furnished us if we turn to the more abstract +departments of thought and inquire what were the Egyptian attempts +in such a field as mathematics. The answer does not tend greatly to +increase our admiration for the Egyptian mind. We are led to see, +indeed, that the Egyptian merchant was able to perform all the +computations necessary to his craft, but we are forced to conclude that +the knowledge of numbers scarcely extended beyond this, and that even +here the methods of reckoning were tedious and cumbersome. Our knowledge +of the subject rests largely upon the so-called papyrus Rhind,(10) which +is a sort of mythological hand-book of the ancient Egyptians. Analyzing +this document, Professor Erman concludes that the knowledge of the +Egyptians was adequate to all practical requirements. Their mathematics +taught them "how in the exchange of bread for beer the respective value +was to be determined when converted into a quantity of corn; how to +reckon the size of a field; how to determine how a given quantity of +corn would go into a granary of a certain size," and like every-day +problems. Yet they were obliged to make some of their simple +computations in a very roundabout way. It would appear, for example, +that their mental arithmetic did not enable them to multiply by a number +larger than two, and that they did not reach a clear conception of +complex fractional numbers. They did, indeed, recognize that each part +of an object divided into 10 pieces became 1/10 of that object; they +even grasped the idea of 2/3 this being a conception easily visualized; +but they apparently did not visualize such a conception as 3/10 except +in the crude form of 1/10 plus 1/10 plus 1/10. Their entire idea +of division seems defective. They viewed the subject from the more +elementary stand-point of multiplication. Thus, in order to find out +how many times 7 is contained in 77, an existing example shows that the +numbers representing 1 times 7, 2 times 7, 4 times 7, 8 times 7 were set +down successively and various experimental additions made to find out +which sets of these numbers aggregated 77. + + --1 7 + --2 14 + --4 28 + --8 56 + +A line before the first, second, and fourth of these numbers indicated +that it is necessary to multiply 7 by 1 plus 2 plus 8--that is, by 11, +in order to obtain 77; that is to say, 7 goes 11 times in 77. All this +seems very cumbersome indeed, yet we must not overlook the fact that the +process which goes on in our own minds in performing such a problem +as this is precisely similar, except that we have learned to slur +over certain of the intermediate steps with the aid of a memorized +multiplication table. In the last analysis, division is only the +obverse side of multiplication, and any one who has not learned his +multiplication table is reduced to some such expedient as that of the +Egyptian. Indeed, whenever we pass beyond the range of our memorized +multiplication table-which for most of us ends with the twelves--the +experimental character of the trial multiplication through which +division is finally effected does not so greatly differ from the +experimental efforts which the Egyptian was obliged to apply to smaller +numbers. + +Despite his defective comprehension of fractions, the Egyptian was +able to work out problems of relative complexity; for example, he could +determine the answer of such a problem as this: a number together with +its fifth part makes 21; what is the number? The process by which the +Egyptian solved this problem seems very cumbersome to any one for whom +a rudimentary knowledge of algebra makes it simple, yet the method +which we employ differs only in that we are enabled, thanks to our +hypothetical x, to make a short cut, and the essential fact must not be +overlooked that the Egyptian reached a correct solution of the problem. +With all due desire to give credit, however, the fact remains that +the Egyptian was but a crude mathematician. Here, as elsewhere, it +is impossible to admire him for any high development of theoretical +science. First, last, and all the time, he was practical, and there is +nothing to show that the thought of science for its own sake, for the +mere love of knowing, ever entered his head. + +In general, then, we must admit that the Egyptian had not progressed far +in the hard way of abstract thinking. He worshipped everything about him +because he feared the result of failing to do so. He embalmed the +dead lest the spirit of the neglected one might come to torment him. +Eye-minded as he was, he came to have an artistic sense, to love +decorative effects. But he let these always take precedence over his +sense of truth; as, for example, when he modified his lists of kings at +Abydos to fit the space which the architect had left to be filled; he +had no historical sense to show to him that truth should take precedence +over mere decoration. And everywhere he lived in the same happy-go-lucky +way. He loved personal ease, the pleasures of the table, the luxuries +of life, games, recreations, festivals. He took no heed for the morrow, +except as the morrow might minister to his personal needs. Essentially +a sensual being, he scarcely conceived the meaning of the intellectual +life in the modern sense of the term. He had perforce learned some +things about astronomy, because these were necessary to his worship +of the gods; about practical medicine, because this ministered to his +material needs; about practical arithmetic, because this aided him in +every-day affairs. The bare rudiments of an historical science may be +said to be crudely outlined in his defective lists of kings. But beyond +this he did not go. Science as science, and for its own sake, was +unknown to him. He had gods for all material functions, and festivals +in honor of every god; but there was no goddess of mere wisdom in his +pantheon. The conception of Minerva was reserved for the creative genius +of another people. + + + + +III. SCIENCE OF BABYLONIA AND ASSYRIA + +Throughout classical antiquity Egyptian science was famous. We know that +Plato spent some years in Egypt in the hope of penetrating the alleged +mysteries of its fabled learning; and the story of the Egyptian priest +who patronizingly assured Solon that the Greeks were but babes was +quoted everywhere without disapproval. Even so late as the time of +Augustus, we find Diodorus, the Sicilian, looking back with veneration +upon the Oriental learning, to which Pliny also refers with unbounded +respect. From what we have seen of Egyptian science, all this furnishes +us with a somewhat striking commentary upon the attainments of the +Greeks and Romans themselves. To refer at length to this would be to +anticipate our purpose; what now concerns us is to recall that all along +there was another nation, or group of nations, that disputed the palm +for scientific attainments. This group of nations found a home in the +valley of the Tigris and Euphrates. Their land was named Mesopotamia by +the Greeks, because a large part of it lay between the two rivers just +mentioned. The peoples themselves are familiar to every one as +the Babylonians and the Assyrians. These peoples were of Semitic +stock--allied, therefore, to the ancient Hebrews and Phoenicians and of +the same racial stem with the Arameans and Arabs. + +The great capital of the Babylonians during the later period of their +history was the famed city of Babylon itself; the most famous capital +of the Assyrians was Nineveh, that city to which, as every Bible-student +will recall, the prophet Jonah was journeying when he had a +much-exploited experience, the record of which forms no part of +scientific annals. It was the kings of Assyria, issuing from their +palaces in Nineveh, who dominated the civilization of Western Asia +during the heyday of Hebrew history, and whose deeds are so frequently +mentioned in the Hebrew chronicles. Later on, in the year 606 B.C., +Nineveh was overthrown by the Medes(1) and Babylonians. The famous city +was completely destroyed, never to be rebuilt. Babylon, however, though +conquered subsequently by Cyrus and held in subjection by Darius,(2) the +Persian kings, continued to hold sway as a great world-capital for some +centuries. The last great historical event that occurred within its +walls was the death of Alexander the Great, which took place there in +the year 322 B.C. + +In the time of Herodotus the fame of Babylon was at its height, and the +father of history has left us a most entertaining account of what he saw +when he visited the wonderful capital. Unfortunately, Herodotus was +not a scholar in the proper acceptance of the term. He probably had no +inkling of the Babylonian language, so the voluminous records of its +literature were entirely shut off from his observation. He therefore +enlightens us but little regarding the science of the Babylonians, +though his observations on their practical civilization give us +incidental references of no small importance. Somewhat more detailed +references to the scientific attainments of the Babylonians are found +in the fragments that have come down to us of the writings of the great +Babylonian historian, Berosus,(3) who was born in Babylon about 330 +B.C., and who was, therefore, a contemporary of Alexander the Great. +But the writings of Berosus also, or at least such parts of them as have +come down to us, leave very much to be desired in point of explicitness. +They give some glimpses of Babylonian history, and they detail at some +length the strange mythical tales of creation that entered into the +Babylonian conception of cosmogony--details which find their counterpart +in the allied recitals of the Hebrews. But taken all in all, the +glimpses of the actual state of Chaldean(4) learning, as it was commonly +called, amounted to scarcely more than vague wonder-tales. No one +really knew just what interpretation to put upon these tales until +the explorers of the nineteenth century had excavated the ruins of the +Babylonian and Assyrian cities, bringing to light the relics of their +wonderful civilization. But these relics fortunately included vast +numbers of written documents, inscribed on tablets, prisms, and +cylinders of terra-cotta. When nineteenth-century scholarship had +penetrated the mysteries of the strange script, and ferreted out the +secrets of an unknown tongue, the world at last was in possession of +authentic records by which the traditions regarding the Babylonians +and Assyrians could be tested. Thanks to these materials, a new science +commonly spoken of as Assyriology came into being, and a most important +chapter of human history was brought to light. It became apparent that +the Greek ideas concerning Mesopotamia, though vague in the extreme, +were founded on fact. No one any longer questions that the Mesopotamian +civilization was fully on a par with that of Egypt; indeed, it is rather +held that superiority lay with the Asiatics. Certainly, in point of +purely scientific attainments, the Babylonians passed somewhat beyond +their Egyptian competitors. All the evidence seems to suggest also that +the Babylonian civilization was even more ancient than that of Egypt. +The precise dates are here in dispute; nor for our present purpose need +they greatly concern us. But the Assyrio-Babylonian records have much +greater historical accuracy as regards matters of chronology than +have the Egyptian, and it is believed that our knowledge of the early +Babylonian history is carried back, with some certainty, to King Sargon +of Agade,(5) for whom the date 3800 B.C. is generally accepted; while +somewhat vaguer records give us glimpses of periods as remote as the +sixth, perhaps even the seventh or eighth millenniums before our era. + +At a very early period Babylon itself was not a capital and Nineveh +had not come into existence. The important cities, such as Nippur and +Shirpurla, were situated farther to the south. It is on the site of +these cities that the recent excavations have been made, such as those +of the University of Pennsylvania expeditions at Nippur,(6) which are +giving us glimpses into remoter recesses of the historical period. + +Even if we disregard the more problematical early dates, we are +still concerned with the records of a civilization extending unbroken +throughout a period of about four thousand years; the actual period is +in all probability twice or thrice that. Naturally enough, the current +of history is not an unbroken stream throughout this long epoch. +It appears that at least two utterly different ethnic elements are +involved. A preponderance of evidence seems to show that the earliest +civilized inhabitants of Mesopotamia were not Semitic, but an alien +race, which is now commonly spoken of as Sumerian. This people, of whom +we catch glimpses chiefly through the records of its successors, appears +to have been subjugated or overthrown by Semitic invaders, who, coming +perhaps from Arabia (their origin is in dispute), took possession of the +region of the Tigris and Euphrates, learned from the Sumerians many of +the useful arts, and, partly perhaps because of their mixed lineage, +were enabled to develop the most wonderful civilization of antiquity. +Could we analyze the details of this civilization from its earliest to +its latest period we should of course find the same changes which always +attend racial progress and decay. We should then be able, no doubt, +to speak of certain golden epochs and their periods of decline. To a +certain meagre extent we are able to do this now. We know, for example, +that King Khammurabi, who lived about 2200 B.C., was a great law-giver, +the ancient prototype of Justinian; and the epochs of such Assyrian +kings as Sargon II., Asshurnazirpal, Sennacherib, and Asshurbanapal +stand out with much distinctness. Yet, as a whole, the record does not +enable us to trace with clearness the progress of scientific thought. +At best we can gain fewer glimpses in this direction than in almost +any other, for it is the record of war and conquest rather than of the +peaceful arts that commanded the attention of the ancient scribe. So +in dealing with the scientific achievements of these peoples, we shall +perforce consider their varied civilizations as a unity, and attempt, +as best we may, to summarize their achievements as a whole. For the most +part, we shall not attempt to discriminate as to what share in the final +product was due to Sumerian, what to Babylonian, and what to Assyrian. +We shall speak of Babylonian science as including all these elements; +and drawing our information chiefly from the relatively late Assyrian +and Babylonian sources, which, therefore, represent the culminating +achievements of all these ages of effort, we shall attempt to discover +what was the actual status of Mesopotamian science at its climax. In so +far as we succeed, we shall be able to judge what scientific heritage +Europe received from the Orient; for in the records of Babylonian +science we have to do with the Eastern mind at its best. Let us turn to +the specific inquiry as to the achievements of the Chaldean scientist +whose fame so dazzled the eyes of his contemporaries of the classic +world. + + +BABYLONIAN ASTRONOMY + +Our first concern naturally is astronomy, this being here, as in Egypt, +the first-born and the most important of the sciences. The fame of the +Chaldean astronomer was indeed what chiefly commanded the admiration of +the Greeks, and it was through the results of astronomical observations +that Babylonia transmitted her most important influences to the Western +world. "Our division of time is of Babylonian origin," says Hornmel;(7) +"to Babylonia we owe the week of seven days, with the names of the +planets for the days of the week, and the division into hours and +months." Hence the almost personal interest which we of to-day must +needs feel in the efforts of the Babylonian star-gazer. + +It must not be supposed, however, that the Chaldean astronomer had +made any very extraordinary advances upon the knowledge of the Egyptian +"watchers of the night." After all, it required patient observation +rather than any peculiar genius in the observer to note in the course of +time such broad astronomical conditions as the regularity of the moon's +phases, and the relation of the lunar periods to the longer periodical +oscillations of the sun. Nor could the curious wanderings of the planets +escape the attention of even a moderately keen observer. The chief +distinction between the Chaldean and Egyptian astronomers appears to +have consisted in the relative importance they attached to various of +the phenomena which they both observed. The Egyptian, as we have seen, +centred his attention upon the sun. That luminary was the abode of +one of his most important gods. His worship was essentially solar. The +Babylonian, on the other hand, appears to have been peculiarly impressed +with the importance of the moon. He could not, of course, overlook the +attention-compelling fact of the solar year; but his unit of time was +the lunar period of thirty days, and his year consisted of twelve lunar +periods, or 360 days. He was perfectly aware, however, that this period +did not coincide with the actual year; but the relative unimportance +which he ascribed to the solar year is evidenced by the fact that he +interpolated an added month to adjust the calendar only once in six +years. Indeed, it would appear that the Babylonians and Assyrians did +not adopt precisely the same method of adjusting the calendar, since the +Babylonians had two intercular months called Elul and Adar, whereas the +Assyrians had only a single such month, called the second Adar.(8) (The +Ve'Adar of the Hebrews.) This diversity further emphasizes the fact that +it was the lunar period which received chief attention, the adjustment +of this period with the solar seasons being a necessary expedient of +secondary importance. It is held that these lunar periods have often +been made to do service for years in the Babylonian computations and in +the allied computations of the early Hebrews. The lives of the Hebrew +patriarchs, for example, as recorded in the Bible, are perhaps reckoned +in lunar "years." Divided by twelve, the "years" of Methuselah accord +fairly with the usual experience of mankind. + +Yet, on the other hand, the convenience of the solar year in computing +long periods of time was not unrecognized, since this period is utilized +in reckoning the reigns of the Assyrian kings. It may be added that the +reign of a king "was not reckoned from the day of his accession, but +from the Assyrian new year's day, either before or after the day of +accession. There does not appear to have been any fixed rule as to which +new year's day should be chosen; but from the number of known cases, it +appears to have been the general practice to count the reigning years +from the new year's day nearest the accession, and to call the period +between the accession day and the first new year's day 'the beginning of +the reign,' when the year from the new year's day was called the +first year, and the following ones were brought successively from +it. Notwithstanding, in the dates of several Assyrian and Babylonian +sovereigns there are cases of the year of accession being considered +as the first year, thus giving two reckonings for the reigns of various +monarchs, among others, Shalmaneser, Sennacherib, Nebuchadrezzar."(9) +This uncertainty as to the years of reckoning again emphasizes the fact +that the solar year did not have for the Assyrian chronology quite the +same significance that it has for us. + +The Assyrian month commenced on the evening when the new moon was first +observed, or, in case the moon was not visible, the new month started +thirty days after the last month. Since the actual lunar period is +about twenty-nine and one-half days, a practical adjustment was required +between the months themselves, and this was probably effected by +counting alternate months as Only 29 days in length. Mr. R. Campbell +Thompson(10) is led by his studies of the astrological tablets to +emphasize this fact. He believes that "the object of the astrological +reports which related to the appearance of the moon and sun was to help +determine and foretell the length of the lunar month." Mr. Thompson +believes also that there is evidence to show that the interculary month +was added at a period less than six years. In point of fact, it does +not appear to be quite clearly established as to precisely how the +adjustment of days with the lunar months, and lunar months with the +solar year, was effected. It is clear, however, according to Smith, +"that the first 28 days of every month were divided into four weeks of +seven days each; the seventh, fourteenth, twenty-first, twenty-eighth +days respectively being Sabbaths, and that there was a general +prohibition of work on these days." Here, of course, is the foundation +of the Hebrew system of Sabbatical days which we have inherited. The +sacredness of the number seven itself--the belief in which has not +been quite shaken off even to this day--was deduced by the Assyrian +astronomer from his observation of the seven planetary bodies--namely, +Sin (the moon), Samas (the sun), Umunpawddu (Jupiter), Dilbat (Venus), +Kaimanu (Saturn), Gudud (Mercury), Mustabarru-mutanu (Mars).(11) Twelve +lunar periods, making up approximately the solar year, gave peculiar +importance to the number twelve also. Thus the zodiac was divided into +twelve signs which astronomers of all subsequent times have continued +to recognize; and the duodecimal system of counting took precedence with +the Babylonian mathematicians over the more primitive and, as it seems +to us, more satisfactory decimal system. + +Another discrepancy between the Babylonian and Egyptian years appears in +the fact that the Babylonian new year dates from about the period of the +vernal equinox and not from the solstice. Lockyer associates this with +the fact that the periodical inundation of the Tigris and Euphrates +occurs about the equinoctial period, whereas, as we have seen, the +Nile flood comes at the time of the solstice. It is but natural that so +important a phenomenon as the Nile flood should make a strong impression +upon the minds of a people living in a valley. The fact that occasional +excessive inundations have led to most disastrous results is evidenced +in the incorporation of stories of the almost total destruction of +mankind by such floods among the myth tales of all peoples who reside in +valley countries. The flooding of the Tigris and Euphrates had not, it +is true, quite the same significance for the Mesopotamians that the +Nile flood had for the Egyptians. Nevertheless it was a most important +phenomenon, and may very readily be imagined to have been the most +tangible index to the seasons. But in recognizing the time of the +inundations and the vernal equinox, the Assyrians did not dethrone +the moon from its accustomed precedence, for the year was reckoned as +commencing not precisely at the vernal equinox, but at the new moon next +before the equinox. + + +ASTROLOGY + +Beyond marking the seasons, the chief interests that actuated the +Babylonian astronomer in his observations were astrological. After +quoting Diodorus to the effect that the Babylonian priests observed the +position of certain stars in order to cast horoscopes, Thompson tells us +that from a very early day the very name Chaldean became synonymous with +magician. He adds that "from Mesopotamia, by way of Greece and Rome, a +certain amount of Babylonian astrology made its way among the nations +of the west, and it is quite probable that many superstitions which we +commonly record as the peculiar product of western civilization took +their origin from those of the early dwellers on the alluvial lands of +Mesopotamia. One Assurbanipal, king of Assyria B.C. 668-626, added to +the royal library at Nineveh his contribution of tablets, which included +many series of documents which related exclusively to the astrology of +the ancient Babylonians, who in turn had borrowed it with modifications +from the Sumerian invaders of the country. Among these must be mentioned +the series which was commonly called 'the Day of Bel,' and which was +decreed by the learned to have been written in the time of the great +Sargon I., king of Agade, 3800 B.C. With such ancient works as these to +guide them, the profession of deducing omens from daily events reached +such a pitch of importance in the last Assyrian Empire that a system +of making periodical reports came into being. By these the king was +informed of all the occurrences in the heavens and on earth, and the +results of astrological studies in respect to after events. The heads +of the astrological profession were men of high rank and position, and +their office was hereditary. The variety of information contained in +these reports is best gathered from the fact that they were sent from +cities as far removed from each other as Assur in the north and Erech +in the south, and it can only be assumed that they were despatched +by runners, or men mounted on swift horses. As reports also came from +Dilbat, Kutba, Nippur, and Bursippa, all cities of ancient foundation, +the king was probably well acquainted with the general course of events +in his empire."(12) + +From certain passages in the astrological tablets, Thompson draws the +interesting conclusion that the Chaldean astronomers were acquainted +with some kind of a machine for reckoning time. He finds in one of the +tablets a phrase which he interprets to mean measure-governor, and +he infers from this the existence of a kind of a calculator. He calls +attention also to the fact that Sextus Empiricus(13) states that the +clepsydra was known to the Chaldeans, and that Herodotus asserts that +the Greeks borrowed certain measures of time from the Babylonians. +He finds further corroboration in the fact that the Babylonians had +a time-measure by which they divided the day and the night; a measure +called kasbu, which contained two hours. In a report relating to the day +of the vernal equinox, it is stated that there are six kasbu of the day +and six kasbu of the night. + +While the astrologers deduced their omens from all the celestial bodies +known to them, they chiefly gave attention to the moon, noting with +great care the shape of its horns, and deducing such a conclusion +as that "if the horns are pointed the king will overcome whatever +he goreth," and that "when the moon is low at its appearance, the +submission (of the people) of a far country will come."(14) The +relations of the moon and sun were a source of constant observation, +it being noted whether the sun and moon were seen together above the +horizon; whether one set as the other rose, and the like. And whatever +the phenomena, there was always, of course, a direct association between +such phenomena and the well-being of human kind--in particular the king, +at whose instance, and doubtless at whose expense, the observations were +carried out. + +From omens associated with the heavenly bodies it is but a step to omens +based upon other phenomena of nature, and we, shall see in a moment that +the Babylonian prophets made free use of their opportunities in this +direction also. But before we turn from the field of astronomy, it will +be well to inform ourselves as to what system the Chaldean astronomer +had invented in explanation of the mechanics of the universe. Our +answer to this inquiry is not quite as definite as could be desired, the +vagueness of the records, no doubt, coinciding with the like vagueness +in the minds of the Chaldeans themselves. So far as we can interpret +the somewhat mystical references that have come down to us, however, +the Babylonian cosmology would seem to have represented the earth as a +circular plane surrounded by a great circular river, beyond which rose +an impregnable barrier of mountains, and resting upon an infinite sea of +waters. The material vault of the heavens was supposed to find support +upon the outlying circle of mountains. But the precise mechanism through +which the observed revolution of the heavenly bodies was effected +remains here, as with the Egyptian cosmology, somewhat conjectural. +The simple fact would appear to be that, for the Chaldeans as for the +Egyptians, despite their most careful observations of the tangible +phenomena of the heavens, no really satisfactory mechanical conception +of the cosmos was attainable. We shall see in due course by what +faltering steps the European imagination advanced from the crude ideas +of Egypt and Babylonia to the relatively clear vision of Newton and +Laplace. + + +CHALDEAN MAGIC + +We turn now from the field of the astrologer to the closely allied +province of Chaldean magic--a province which includes the other; +which, indeed, is so all-encompassing as scarcely to leave any phase of +Babylonian thought outside its bounds. + +The tablets having to do with omens, exorcisms, and the like magic +practices make up an astonishingly large proportion of the Babylonian +records. In viewing them it is hard to avoid the conclusion that the +superstitions which they evidenced absolutely dominated the life of +the Babylonians of every degree. Yet it must not be forgotten that the +greatest inconsistencies everywhere exist between the superstitious +beliefs of a people and the practical observances of that people. No +other problem is so difficult for the historian as that which confronts +him when he endeavors to penetrate the mysteries of an alien religion; +and when, as in the present case, the superstitions involved have been +transmitted from generation to generation, their exact practical +phases as interpreted by any particular generation must be somewhat +problematical. The tablets upon which our knowledge of these omens is +based are many of them from the libraries of the later kings of Nineveh; +but the omens themselves are, in such cases, inscribed in the original +Accadian form in which they have come down from remote ages, accompanied +by an Assyrian translation. Thus the superstitions involved had back of +them hundreds of years, even thousands of years, of precedent; and +we need not doubt that the ideas with which they are associated were +interwoven with almost every thought and deed of the life of the people. +Professor Sayce assures us that the Assyrians and Babylonians counted no +fewer than three hundred spirits of heaven, and six hundred spirits of +earth. "Like the Jews of the Talmud," he says, "they believed that +the world was swarming with noxious spirits, who produced the various +diseases to which man is liable, and might be swallowed with the food +and drink which support life." Fox Talbot was inclined to believe that +exorcisms were the exclusive means used to drive away the tormenting +spirits. This seems unlikely, considering the uniform association +of drugs with the magical practices among their people. Yet there is +certainly a strange silence of the tablets in regard to medicine. +Talbot tells us that sometimes divine images were brought into the +sick-chamber, and written texts taken from holy books were placed on the +walls and bound around the sick man's members. If these failed, recourse +was had to the influence of the mamit, which the evil powers were unable +to resist. On a tablet, written in the Accadian language only, the +Assyrian version being taken, however, was found the following: + + 1. Take a white cloth. In it place the mamit, + 2. in the sick man's right hand. + 3. Take a black cloth, + 4. wrap it around his left hand. + 5. Then all the evil spirits (a long list of them is given) + 6. and the sins which he has committed + 7. shall quit their hold of him + 8. and shall never return. + + +The symbolism of the black cloth in the left hand seems evident. The +dying man repents of his former evil deeds, and he puts his trust in +holiness, symbolized by the white cloth in his right hand. Then follow +some obscure lines about the spirits: + + 1. Their heads shall remove from his head. + 2. Their heads shall let go his hands. + 3. Their feet shall depart from his feet. + +Which perhaps may be explained thus: we learn from another tablet that +the various classes of evil spirits troubled different parts of +the body; some injured the head, some the hands and the feet, etc., +therefore the passage before may mean "the spirits whose power is +over the hand shall loose their hands from his," etc. "But," concludes +Talbot, "I can offer no decided opinion upon such obscure points of +their superstition."(15) + +In regard to evil spirits, as elsewhere, the number seven had a peculiar +significance, it being held that that number of spirits might enter into +a man together. Talbot has translated(16) a "wild chant" which he names +"The Song of the Seven Spirits." + + 1. There are seven! There are seven! + 2. In the depths of the ocean there are seven! + 3. In the heights of the heaven there are seven! + 4. In the ocean stream in a palace they were born. + 5. Male they are not: female they are not! + 6. Wives they have not! Children are not born to them! + 7. Rules they have not! Government they know not! + 8. Prayers they hear not! + 9. There are seven! There are seven! Twice over there are +seven! + +The tablets make frequent allusion to these seven spirits. One starts +thus: + + 1. The god (---) shall stand by his bedside; + 2. These seven evil spirits he shall root out and shall expel +them from his body, 3. and these seven shall never return to the sick man +again.(17) + + +Altogether similar are the exorcisms intended to ward off disease. +Professor Sayce has published translations of some of these.(18) Each of +these ends with the same phrase, and they differ only in regard to the +particular maladies from which freedom is desired. One reads: + +"From wasting, from want of health, from the evil spirit of the ulcer, +from the spreading quinsy of the gullet, from the violent ulcer, from +the noxious ulcer, may the king of heaven preserve, may the king of +earth preserve." + +Another is phrased thus: + +"From the cruel spirit of the head, from the strong spirit of the head, +from the head spirit that departs not, from the head spirit that comes +not forth, from the head spirit that will not go, from the noxious +head spirit, may the king of heaven preserve, may the king of earth +preserve." + +As to omens having to do with the affairs of everyday life the number +is legion. For example, Moppert has published, in the Journal +Asiatique,(19) the translation of a tablet which contains on its two +sides several scores of birth-portents, a few of which maybe quoted at +random: + +"When a woman bears a child and it has the ears of a lion, a strong +king is in the country." "When a woman bears a child and it has a bird's +beak, that country is oppressed." "When a woman bears a child and its +right hand is wanting, that country goes to destruction." "When a woman +bears a child and its feet are wanting, the roads of the country are +cut; that house is destroyed." "When a woman bears a child and at the +time of its birth its beard is grown, floods are in the country." "When +a woman bears a child and at the time of its birth its mouth is open and +speaks, there is pestilence in the country, the Air-god inundates the +crops of the country, injury in the country is caused." + +Some of these portents, it will be observed, are not in much danger +of realization, and it is curious to surmise by what stretch of the +imagination they can have been invented. There is, for example, on the +same tablet just quoted, one reference which assures us that "when a +sheep bears a lion the forces march multitudinously; the king has not a +rival." There are other omens, however, that are so easy of realization +as to lead one to suppose that any Babylonian who regarded all the +superstitious signs must have been in constant terror. Thus a tablet +translated by Professor Sayce(20) gives a long list of omens furnished +by dogs, in which we are assured that: + + 1. If a yellow dog enters into the palace, exit from that + palace will be baleful. + 2. If a dog to the palace goes, and on a throne lies down, that + palace is burned. + 3. If a black dog into a temple enters, the foundation of that + temple is not stable. + 4. If female dogs one litter bear, destruction to the city. + +It is needless to continue these citations, since they but reiterate +endlessly the same story. It is interesting to recall, however, that the +observations of animate nature, which were doubtless superstitious in +their motive, had given the Babylonians some inklings of a knowledge of +classification. Thus, according to Menant,(21) some of the tablets from +Nineveh, which are written, as usual, in both the Sumerian and Assyrian +languages, and which, therefore, like practically all Assyrian books, +draw upon the knowledge of old Babylonia, give lists of animals, making +an attempt at classification. The dog, lion, and wolf are placed in one +category; the ox, sheep, and goat in another; the dog family itself is +divided into various races, as the domestic dog, the coursing dog, the +small dog, the dog of Elan, etc. Similar attempts at classification of +birds are found. Thus, birds of rapid flight, sea-birds, and marsh-birds +are differentiated. Insects are classified according to habit; those +that attack plants, animals, clothing, or wood. Vegetables seem to be +classified according to their usefulness. One tablet enumerates the uses +of wood according to its adaptability for timber-work of palaces, or +construction of vessels, the making of implements of husbandry, or even +furniture. Minerals occupy a long series in these tablets. They are +classed according to their qualities, gold and silver occupying a +division apart; precious stones forming another series. Our Babylonians, +then, must be credited with the development of a rudimentary science of +natural history. + + +BABYLONIAN MEDICINE + +We have just seen that medical practice in the Babylonian world was +strangely under the cloud of superstition. But it should be understood +that our estimate, through lack of correct data, probably does much less +than justice to the attainments of the physician of the time. As already +noted, the existing tablets chance not to throw much light on the +subject. It is known, however, that the practitioner of medicine +occupied a position of some, authority and responsibility. The proof +of this is found in the clauses relating to the legal status of +the physician which are contained in the now famous code(22) of the +Babylonian King Khamurabi, who reigned about 2300 years before our era. +These clauses, though throwing no light on the scientific attainments +of the physician of the period, are too curious to be omitted. They are +clauses 215 to 227 of the celebrated code, and are as follows: + +215. If a doctor has treated a man for a severe wound with a lancet of +bronze and has cured the man, or has opened a tumor with a bronze lancet +and has cured the man's eye, he shall receive ten shekels of silver. + +216. If it was a freedman, he shall receive five shekels of silver. + +217. If it was a man's slave, the owner of the slave shall give the +doctor two shekels of silver. + +218. If a physician has treated a free-born man for a severe wound with +a lancet of bronze and has caused the man to die, or has opened a tumor +of the man with a lancet of bronze and has destroyed his eye, his hands +one shall cut off. + +219. If the doctor has treated the slave of a freedman for a severe +wound with a bronze lancet and has caused him to die, he shall give back +slave for slave. + +220. If he has opened his tumor with a bronze lancet and has ruined his +eye, he shall pay the half of his price in money. + +221. If a doctor has cured the broken limb of a man, or has healed his +sick body, the patient shall pay the doctor five shekels of silver. + +222. If it was a freedman, he shall give three shekels of silver. + +223. If it was a man's slave, the owner of the slave shall give two +shekels of silver to the doctor. + +224. If the doctor of oxen and asses has treated an ox or an ass for a +grave wound and has cured it, the owner of the ox or the ass shall give +to the doctor as his pay one-sixth of a shekel of silver. + +225. If he has treated an ox or an ass for a severe wound and has caused +its death, he shall pay one-fourth of its price to the owner of the ox +or the ass. + +226. If a barber-surgeon, without consent of the owner of a slave, has +branded the slave with an indelible mark, one shall cut off the hands of +that barber. + +227. If any one deceive the surgeon-barber and make him brand a slave +with an indelible mark, one shall kill that man and bury him in his +house. The barber shall swear, "I did not mark him wittingly," and he +shall be guiltless. + + +ESTIMATES OF BABYLONIAN SCIENCE + +Before turning from the Oriental world it is perhaps worth while to +attempt to estimate somewhat specifically the world-influence of the +name, Babylonian science. Perhaps we cannot better gain an idea as to +the estimate put upon that science by the classical world than through +a somewhat extended quotation from a classical author. Diodorus Siculus, +who, as already noted, lived at about the time of Augustus, and who, +therefore, scanned in perspective the entire sweep of classical Greek +history, has left us a striking summary which is doubly valuable because +of its comparisons of Babylonian with Greek influence. Having viewed the +science of Babylonia in the light of the interpretations made possible +by the recent study of original documents, we are prepared to draw our +own conclusions from the statements of the Greek historian. Here is his +estimate in the words of the quaint translation made by Philemon Holland +in the year 1700:(23) + + +"They being the most ancient Babylonians, hold the same station and +dignity in the Common-wealth as the Egyptian Priests do in Egypt: For +being deputed to Divine Offices, they spend all their Time in the study +of Philosophy, and are especially famous for the Art of Astrology. They +are mightily given to Divination, and foretel future Events, and imploy +themselves either by Purifications, Sacrifices, or other Inchantments +to avert Evils, or procure good Fortune and Success. They are skilful +likewise in the Art of Divination, by the flying of Birds, and +interpreting of Dreams and Prodigies: And are reputed as true Oracles +(in declaring what will come to pass) by their exact and diligent +viewing the Intrals of the Sacrifices. But they attain not to this +Knowledge in the same manner as the Grecians do; for the Chaldeans learn +it by Tradition from their Ancestors, the Son from the Father, who +are all in the mean time free from all other publick Offices and +Attendances; and because their Parents are their Tutors, they both learn +every thing without Envy, and rely with more confidence upon the truth +of what is taught them; and being train'd up in this Learning, from +their very Childhood, they become most famous Philosophers, (that Age +being most capable of Learning, wherein they spend much of their time). +But the Grecians for the most part come raw to this study, unfitted and +unprepar'd, and are long before they attain to the Knowledge of this +Philosophy: And after they have spent some small time in this Study, +they are many times call'd off and forc'd to leave it, in order to get +a Livelihood and Subsistence. And although some, few do industriously +apply themselves to Philosophy, yet for the sake of Gain, these very Men +are opinionative, and ever and anon starting new and high Points, and +never fix in the steps of their Ancestors. But the Barbarians keeping +constantly close to the same thing, attain to a perfect and distinct +Knowledge in every particular. + +"But the Grecians, cunningly catching at all Opportunities of Gain, +make new Sects and Parties, and by their contrary Opinions wrangling and +quarelling concerning the chiefest Points, lead their Scholars into a +Maze; and being uncertain and doubtful what to pitch upon for certain +truth, their Minds are fluctuating and in suspence all the days of their +Lives, and unable to give a certain assent unto any thing. For if any +Man will but examine the most eminent Sects of the Philosophers, he +shall find them much differing among themselves, and even opposing one +another in the most weighty parts of their Philosophy. But to return to +the Chaldeans, they hold that the World is eternal, which had neither +any certain Beginning, nor shall have any End; but all agree, that all +things are order'd, and this beautiful Fabrick is supported by a Divine +Providence, and that the Motions of the Heavens are not perform'd by +chance and of their own accord, but by a certain and determinate Will +and Appointment of the Gods. + +"Therefore from a long observation of the Stars, and an exact Knowledge +of the motions and influences of every one of them, wherein they excel +all others, they fortel many things that are to come to pass. + +"They say that the Five Stars which some call Planets, but they +Interpreters, are most worthy of Consideration, both for their motions +and their remarkable influences, especially that which the Grecians call +Saturn. The brightest of them all, and which often portends many and +great Events, they call Sol, the other Four they name Mars, Venus, +Mercury, and Jupiter, with our own Country Astrologers. They give the +Name of Interpreters to these Stars, because these only by a peculiar +Motion do portend things to come, and instead of Jupiters, do declare to +Men before-hand the good-will of the Gods; whereas the other Stars (not +being of the number of the Planets) have a constant ordinary motion. +Future Events (they say) are pointed at sometimes by their Rising, and +sometimes by their Setting, and at other times by their Colour, as +may be experienc'd by those that will diligently observe it; sometimes +foreshewing Hurricanes, at other times Tempestuous Rains, and then +again exceeding Droughts. By these, they say, are often portended the +appearance of Comets, Eclipses of the Sun and Moon, Earthquakes and all +other the various Changes and remarkable effects in the Air, boding +good and bad, not only to Nations in general, but to Kings and Private +Persons in particular. Under the course of these Planets, they say are +Thirty Stars, which they call Counselling Gods, half of whom observe +what is done under the Earth, and the other half take notice of the +actions of Men upon the Earth, and what is transacted in the Heavens. +Once every Ten Days space (they say) one of the highest Order of these +Stars descends to them that are of the lowest, like a Messenger sent +from them above; and then again another ascends from those below to them +above, and that this is their constant natural motion to continue for +ever. The chief of these Gods, they say, are Twelve in number, to each +of which they attribute a Month, and one Sign of the Twelve in the +Zodiack. + +"Through these Twelve Signs the Sun, Moon, and the other Five Planets +run their Course. The Sun in a Years time, and the Moon in the space +of a Month. To every one of the Planets they assign their own proper +Courses, which are perform'd variously in lesser or shorter time +according as their several motions are quicker or slower. These Stars, +they say, have a great influence both as to good and bad in Mens +Nativities; and from the consideration of their several Natures, may +be foreknown what will befal Men afterwards. As they foretold things +to come to other Kings formerly, so they did to Alexander who conquer'd +Darius, and to his Successors Antigonus and Seleucus Nicator; and +accordingly things fell out as they declar'd; which we shall relate +particularly hereafter in a more convenient time. They tell likewise +private Men their Fortunes so certainly, that those who have found the +thing true by Experience, have esteem'd it a Miracle, and above the +reach of man to perform. Out of the Circle of the Zodiack they describe +Four and Twenty Stars, Twelve towards the North Pole, and as many to the +South. + +"Those which we see, they assign to the living; and the other that do +not appear, they conceive are Constellations for the Dead; and they term +them Judges of all things. The Moon, they say, is in the lowest Orb; +and being therefore next to the Earth (because she is so small), she +finishes her Course in a little time, not through the swiftness of her +Motion, but the shortness of her Sphear. In that which they affirm (that +she has but a borrow'd light, and that when she is eclips'd, it's caus'd +by the interposition of the shadow of the Earth) they agree with the +Grecians. + +"Their Rules and Notions concerning the Eclipses of the Sun are but weak +and mean, which they dare not positively foretel, nor fix a certain time +for them. They have likewise Opinions concerning the Earth peculiar to +themselves, affirming it to resemble a Boat, and to be hollow, to prove +which, and other things relating to the frame of the World, they abound +in Arguments; but to give a particular Account of 'em, we conceive would +be a thing foreign to our History. But this any Man may justly and truly +say, That the Chaldeans far exceed all other Men in the Knowledge of +Astrology, and have study'd it most of any other Art or Science: But +the number of years during which the Chaldeans say, those of their +Profession have given themselves to the study of this natural +Philosophy, is incredible; for when Alexander was in Asia, they reckon'd +up Four Hundred and Seventy Thousand Years since they first began to +observe the Motions of the Stars." + + +Let us now supplement this estimate of Babylonian influence with another +estimate written in our own day, and quoted by one of the most recent +historians of Babylonia and Assyria.(24) The estimate in question +is that of Canon Rawlinson in his Great Oriental Monarchies.(25) Of +Babylonia he says: + +"Hers was apparently the genius which excogitated an alphabet; worked +out the simpler problems of arithmetic; invented implements for +measuring the lapse of time; conceived the idea of raising enormous +structures with the poorest of all materials, clay; discovered the art +of polishing, boring, and engraving gems; reproduced with truthfulness +the outlines of human and animal forms; attained to high perfection +in textile fabrics; studied with success the motions of the heavenly +bodies; conceived of grammar as a science; elaborated a system of law; +saw the value of an exact chronology--in almost every branch of science +made a beginning, thus rendering it comparatively easy for other nations +to proceed with the superstructure.... It was from the East, not from +Egypt, that Greece derived her architecture, her sculpture, her science, +her philosophy, her mathematical knowledge--in a word, her intellectual +life. And Babylon was the source to which the entire stream of Eastern +civilization may be traced. It is scarcely too much to say that, but for +Babylon, real civilization might not yet have dawned upon the earth." + + +Considering that a period of almost two thousand years separates the +times of writing of these two estimates, the estimates themselves are +singularly in unison. They show that the greatest of Oriental nations +has not suffered in reputation at the hands of posterity. It is indeed +almost impossible to contemplate the monuments of Babylonian and +Assyrian civilization that are now preserved in the European and +American museums without becoming enthusiastic. That certainly was +a wonderful civilization which has left us the tablets on which are +inscribed the laws of a Khamurabi on the one hand, and the art +treasures of the palace of an Asshurbanipal on the other. Yet a candid +consideration of the scientific attainments of the Babylonians and +Assyrians can scarcely arouse us to a like enthusiasm. In considering +the subject we have seen that, so far as pure science is concerned, +the efforts of the Babylonians and Assyrians chiefly centred about the +subjects of astrology and magic. With the records of their ghost-haunted +science fresh in mind, one might be forgiven for a momentary desire +to take issue with Canon Rawlinson's words. We are assured that the +scientific attainments of Europe are almost solely to be credited to +Babylonia and not to Egypt, but we should not forget that Plato, the +greatest of the Greek thinkers, went to Egypt and not to Babylonia to +pursue his studies when he wished to penetrate the secrets of Oriental +science and philosophy. Clearly, then, classical Greece did not consider +Babylonia as having a monopoly of scientific knowledge, and we of +to-day, when we attempt to weigh the new evidence that has come to us +in recent generations with the Babylonian records themselves, find that +some, at least, of the heritages for which Babylonia has been praised +are of more than doubtful value. Babylonia, for example, gave us our +seven-day week and our system of computing by twelves. But surely the +world could have got on as well without that magic number seven; and +after some hundreds of generations we are coming to feel that the +decimal system of the Egyptians has advantages over the duodecimal +system of the Babylonians. Again, the Babylonians did not invent the +alphabet; they did not even accept it when all the rest of the world had +recognized its value. In grammar and arithmetic, as with astronomy, they +seemed not to have advanced greatly, if at all, upon the Egyptians. One +field in which they stand out in startling pre-eminence is the field +of astrology; but this, in the estimate of modern thought, is the +very negation of science. Babylonia impressed her superstitions on +the Western world, and when we consider the baleful influence of these +superstitions, we may almost question whether we might not reverse +Canon Rawlinson's estimate and say that perhaps but for Babylonia real +civilization, based on the application of true science, might have +dawned upon the earth a score of centuries before it did. Yet, after +all, perhaps this estimate is unjust. Society, like an individual +organism, must creep before it can walk, and perhaps the Babylonian +experiments in astrology and magic, which European civilization was +destined to copy for some three or four thousand years, must have been +made a part of the necessary evolution of our race in one place or in +another. That thought, however, need not blind us to the essential +fact, which the historian of science must needs admit, that for the +Babylonian, despite his boasted culture, science spelled superstition. + + + + +IV. THE DEVELOPMENT OF THE ALPHABET + +Before we turn specifically to the new world of the west, it remains +to take note of what may perhaps be regarded as the very greatest +achievement of ancient science. This was the analysis of speech sounds, +and the resulting development of a system of alphabetical writing. To +comprehend the series of scientific inductions which led to this result, +we must go back in imagination and trace briefly the development of +the methods of recording thought by means of graphic symbols. In other +words, we must trace the evolution of the art of writing. In doing so +we cannot hold to national lines as we have done in the preceding two +chapters, though the efforts of the two great scientific nations just +considered will enter prominently into the story. + +The familiar Greek legend assures us that a Phoenician named Kadmus was +the first to bring a knowledge of letters into Europe. An elaboration +of the story, current throughout classical times, offered the further +explanation that the Phoenicians had in turn acquired the art of writing +from the Egyptians or Babylonians. Knowledge as to the true origin and +development of the art of writing did not extend in antiquity beyond +such vagaries as these. Nineteenth-century studies gave the first +real clews to an understanding of the subject. These studies tended +to authenticate the essential fact on which the legend of Kadmus was +founded; to the extent, at least, of making it probable that the later +Grecian alphabet was introduced from Phoenicia--though not, of course, +by any individual named Kadmus, the latter being, indeed, a name of +purely Greek origin. Further studies of the past generation tended +to corroborate the ancient belief as to the original source of the +Phoenician alphabet, but divided scholars between two opinions: the one +contending that the Egyptian hieroglyphics were the source upon which +the Phoenicians drew; and the other contending with equal fervor that +the Babylonian wedge character must be conceded that honor. + +But, as has often happened in other fields after years of acrimonious +controversy, a new discovery or two may suffice to show that neither +contestant was right. After the Egyptologists of the school of De +Rouge(1) thought they had demonstrated that the familiar symbols of the +Phoenician alphabet had been copied from that modified form of Egyptian +hieroglyphics known as the hieratic writing, the Assyriologists came +forward to prove that certain characters of the Babylonian syllabary +also show a likeness to the alphabetical characters that seemingly could +not be due to chance. And then, when a settlement of the dispute seemed +almost hopeless, it was shown through the Egyptian excavations that +characters even more closely resembling those in dispute had been in use +all about the shores of the Mediterranean, quite independently of +either Egyptian or Assyrian writings, from periods so ancient as to be +virtually prehistoric. + +Coupled with this disconcerting discovery are the revelations brought to +light by the excavations at the sites of Knossos and other long-buried +cities of the island of Crete.(2) These excavations, which are still +in progress, show that the art of writing was known and practised +independently in Crete before that cataclysmic overthrow of the early +Greek civilization which archaeologists are accustomed to ascribe to the +hypothetical invasion of the Dorians. The significance of this is that +the art of writing was known in Europe long before the advent of the +mythical Kadmus. But since the early Cretan scripts are not to be +identified with the scripts used in Greece in historical times, whereas +the latter are undoubtedly of lineal descent from the Phoenician +alphabet, the validity of the Kadmus legend, in a modified form, must +still be admitted. + +As has just been suggested, the new knowledge, particularly that which +related to the great antiquity of characters similar to the Phoenician +alphabetical signs, is somewhat disconcerting. Its general trend, +however, is quite in the same direction with most of the new +archaeological knowledge of recent decades---that is to say, it tends +to emphasize the idea that human civilization in most of its important +elaborations is vastly older than has hitherto been supposed. It may be +added, however, that no definite clews are as yet available that enable +us to fix even an approximate date for the origin of the Phoenician +alphabet. The signs, to which reference has been made, may well have +been in existence for thousands of years, utilized merely as property +marks, symbols for counting and the like, before the idea of setting +them aside as phonetic symbols was ever conceived. Nothing is more +certain, in the judgment of the present-day investigator, than that man +learned to write by slow and painful stages. It is probable that the +conception of such an analysis of speech sounds as would make the idea +of an alphabet possible came at a very late stage of social evolution, +and as the culminating achievement of a long series of improvements +in the art of writing. The precise steps that marked this path of +intellectual development can for the most part be known only by +inference; yet it is probable that the main chapters of the story may be +reproduced with essential accuracy. + + +FIRST STEPS + +For the very first chapters of the story we must go back in imagination +to the prehistoric period. Even barbaric man feels the need of +self-expression, and strives to make his ideas manifest to other men by +pictorial signs. The cave-dwellers scratched pictures of men and animals +on the surface of a reindeer horn or mammoth tusk as mementos of his +prowess. The American Indian does essentially the same thing to-day, +making pictures that crudely record his successes in war and the chase. +The Northern Indian had got no farther than this when the white man +discovered America; but the Aztecs of the Southwest and the Maya people +of Yucatan had carried their picture-making to a much higher state +of elaboration.(3) They had developed systems of pictographs or +hieroglyphics that would doubtless in the course of generations have +been elaborated into alphabetical systems, had not the Europeans cut off +the civilization of which they were the highest exponents. + +What the Aztec and Maya were striving towards in the sixteenth century +A.D., various Oriental nations had attained at least five or six +thousand years earlier. In Egypt at the time of the pyramid-builders, +and in Babylonia at the same epoch, the people had developed systems of +writing that enabled them not merely to present a limited range of ideas +pictorially, but to express in full elaboration and with finer shades of +meaning all the ideas that pertain to highly cultured existence. The +man of that time made records of military achievements, recorded the +transactions of every-day business life, and gave expression to his +moral and spiritual aspirations in a way strangely comparable to the +manner of our own time. He had perfected highly elaborate systems of +writing. + + +EGYPTIAN WRITING + +Of the two ancient systems of writing just referred to as being in +vogue at the so-called dawnings of history, the more picturesque and +suggestive was the hieroglyphic system of the Egyptians. This is a +curiously conglomerate system of writing, made up in part of symbols +reminiscent of the crudest stages of picture-writing, in part of symbols +having the phonetic value of syllables, and in part of true alphabetical +letters. In a word, the Egyptian writing represents in itself the +elements of the various stages through which the art of writing has +developed.(4) We must conceive that new features were from time to time +added to it, while the old features, curiously enough, were not given +up. + +Here, for example, in the midst of unintelligible lines and pot-hooks, +are various pictures that are instantly recognizable as representations +of hawks, lions, ibises, and the like. It can hardly be questioned that +when these pictures were first used calligraphically they were meant to +represent the idea of a bird or animal. In other words, the first stage +of picture-writing did not go beyond the mere representation of an +eagle by the picture of an eagle. But this, obviously, would confine +the presentation of ideas within very narrow limits. In due course some +inventive genius conceived the thought of symbolizing a picture. To him +the outline of an eagle might represent not merely an actual bird, but +the thought of strength, of courage, or of swift progress. Such a use +of symbols obviously extends the range of utility of a nascent art of +writing. Then in due course some wonderful psychologist--or perhaps the +joint efforts of many generations of psychologists--made the astounding +discovery that the human voice, which seems to flow on in an unbroken +stream of endlessly varied modulations and intonations, may really be +analyzed into a comparatively limited number of component sounds--into a +few hundreds of syllables. That wonderful idea conceived, it was only +a matter of time until it would occur to some other enterprising genius +that by selecting an arbitrary symbol to represent each one of these +elementary sounds it would be possible to make a written record of the +words of human speech which could be reproduced--rephonated--by some +one who had never heard the words and did not know in advance what this +written record contained. This, of course, is what every child learns +to do now in the primer class, but we may feel assured that such an +idea never occurred to any human being until the peculiar forms of +pictographic writing just referred to had been practised for many +centuries. Yet, as we have said, some genius of prehistoric Egypt +conceived the idea and put it into practical execution, and the +hieroglyphic writing of which the Egyptians were in full possession at +the very beginning of what we term the historical period made use +of this phonetic system along with the ideographic system already +described. + +So fond were the Egyptians of their pictorial symbols used +ideographically that they clung to them persistently throughout the +entire period of Egyptian history. They used symbols as phonetic +equivalents very frequently, but they never learned to depend upon them +exclusively. The scribe always interspersed his phonetic signs with some +other signs intended as graphic aids. After spelling a word out in full, +he added a picture, sometimes even two or three pictures, representative +of the individual thing, or at least of the type of thing to which the +word belongs. Two or three illustrations will make this clear. + +Thus qeften, monkey, is spelled out in full, but the picture of a monkey +is added as a determinative; second, qenu, cavalry, after being spelled, +is made unequivocal by the introduction of a picture of a horse; third, +temati, wings, though spelled elaborately, has pictures of wings added; +and fourth, tatu, quadrupeds, after being spelled, has a picture of +a quadruped, and then the picture of a hide, which is the usual +determinative of a quadruped, followed by three dashes to indicate the +plural number. + +It must not be supposed, however, that it was a mere whim which led the +Egyptians to the use of this system of determinatives. There was sound +reason back of it. It amounted to no more than the expedient we adopt +when we spell "to," "two," or "too," in indication of a single sound +with three different meanings. The Egyptian language abounds in words +having more than one meaning, and in writing these it is obvious that +some means of distinction is desirable. The same thing occurs even more +frequently in the Chinese language, which is monosyllabic. The Chinese +adopt a more clumsy expedient, supplying a different symbol for each +of the meanings of a syllable; so that while the actual word-sounds of +their speech are only a few hundreds in number, the characters of their +written language mount high into the thousands. + + +BABYLONIAN WRITING + +While the civilization of the Nile Valley was developing this +extraordinary system of hieroglyphics, the inhabitants of Babylonia +were practising the art of writing along somewhat different lines. It is +certain that they began with picture-making, and that in due course they +advanced to the development of the syllabary; but, unlike their Egyptian +cousins, the men of Babylonia saw fit to discard the old system when +they had perfected a better one.(5) So at a very early day their +writing--as revealed to us now through the recent excavations--had +ceased to have that pictorial aspect which distinguishes the Egyptian +script. What had originally been pictures of objects--fish, houses, +and the like--had come to be represented by mere aggregations of +wedge-shaped marks. As the writing of the Babvlonians was chiefly +inscribed on soft clay, the adaptation of this wedge-shaped mark in lieu +of an ordinary line was probably a mere matter of convenience, since the +sharp-cornered implement used in making the inscription naturally made +a wedge-shaped impression in the clay. That, however, is a detail. +The essential thing is that the Babylonian had so fully analyzed +the speech-sounds that he felt entire confidence in them, and having +selected a sufficient number of conventional characters--each made up +of wedge-shaped lines--to represent all the phonetic sounds of his +language, spelled the words out in syllables and to some extent +dispensed with the determinative signs which, as we have seen, played so +prominent a part in the Egyptian writing. His cousins the Assyrians used +habitually a system of writing the foundation of which was an elaborate +phonetic syllabary; a system, therefore, far removed from the old +crude pictograph, and in some respects much more developed than the +complicated Egyptian method; yet, after all, a system that stopped short +of perfection by the wide gap that separates the syllabary from the true +alphabet. + +A brief analysis of speech sounds will aid us in understanding the real +nature of the syllabary. Let us take for consideration the consonantal +sound represented by the letter b. A moment's consideration will make +it clear that this sound enters into a large number of syllables. There +are, for example, at least twenty vowel sounds in the English language, +not to speak of certain digraphs; that is to say, each of the important +vowels has from two to six sounds. Each of these vowel sounds may enter +into combination with the b sound alone to form three syllables; as +ba, ab, bal, be, eb, bel, etc. Thus there are at least sixty b-sound +syllables. But this is not the end, for other consonantal sounds may be +associated in the syllables in such combinations as bad, bed, bar, bark, +cab, etc. As each of the other twenty odd consonantal sounds may enter +into similar combinations, it is obvious that there are several hundreds +of fundamental syllables to be taken into account in any syllabic system +of writing. For each of these syllables a symbol must be set aside +and held in reserve as the representative of that particular sound. A +perfect syllabary, then, would require some hundred or more of symbols +to represent b sounds alone; and since the sounds for c, d, f, and the +rest are equally varied, the entire syllabary would run into thousands +of characters, almost rivalling in complexity the Chinese system. But +in practice the most perfect syllabary, Such as that of the Babylonians, +fell short of this degree of precision through ignoring the minor shades +of sound; just as our own alphabet is content to represent some thirty +vowel sounds by five letters, ignoring the fact that a, for example, has +really half a dozen distinct phonetic values. By such slurring of sounds +the syllabary is reduced far below its ideal limits; yet even so it +retains three or four hundred characters. + +In point of fact, such a work as Professor Delitzsch's Assyrian +Grammar(6) presents signs for three hundred and thirty-four syllables, +together with sundry alternative signs and determinatives to tax the +memory of the would-be reader of Assyrian. Let us take for example a few +of the b sounds. It has been explained that the basis of the Assyrian +written character is a simple wedge-shaped or arrow-head mark. Variously +repeated and grouped, these marks make up the syllabic characters. + +To learn some four hundred such signs as these was the task set, as an +equivalent of learning the a b c's, to any primer class in old Assyria +in the long generations when that land was the culture Centre of the +world. Nor was the task confined to the natives of Babylonia and Assyria +alone. About the fifteenth century B.C., and probably for a long time +before and after that period, the exceedingly complex syllabary of the +Babylonians was the official means of communication throughout western +Asia and between Asia and Egypt, as we know from the chance discovery +of a collection of letters belonging to the Egyptian king Khun-aten, +preserved at Tel-el-Amarna. In the time of Ramses the Great the +Babylonian writing was in all probability considered by a majority of +the most highly civilized people in the world to be the most perfect +script practicable. Doubtless the average scribe of the time did not in +the least realize the waste of energy involved in his labors, or ever +suspect that there could be any better way of writing. + +Yet the analysis of any one of these hundreds of syllables into its +component phonetic elements--had any one been genius enough to make such +analysis--would have given the key to simpler and better things. But +such an analysis was very hard to make, as the sequel shows. Nor is +the utility of such an analysis self-evident, as the experience of +the Egyptians proved. The vowel sound is so intimately linked with the +consonant--the con-sonant, implying this intimate relation in its +very name--that it seemed extremely difficult to give it individual +recognition. To set off the mere labial beginning of the sound by +itself, and to recognize it as an all-essential element of phonation, +was the feat at which human intelligence so long balked. The germ of +great things lay in that analysis. It was a process of simplification, +and all art development is from the complex to the simple. +Unfortunately, however, it did not seem a simplification, but rather +quite the reverse. We may well suppose that the idea of wresting from +the syllabary its secret of consonants and vowels, and giving to +each consonantal sound a distinct sign, seemed a most cumbersome and +embarrassing complication to the ancient scholars--that is to say, +after the time arrived when any one gave such an idea expression. We can +imagine them saying: "You will oblige us to use four signs instead of +one to write such an elementary syllable as 'bard,' for example. +Out upon such endless perplexity!" Nor is such a suggestion purely +gratuitous, for it is an historical fact that the old syllabary +continued to be used in Babylon hundreds of years after the alphabetical +system had been introduced.(7) Custom is everything in establishing our +prejudices. The Japanese to-day rebel against the introduction of an +alphabet, thinking it ambiguous. + +Yet, in the end, conservatism always yields, and so it was with +opposition to the alphabet. Once the idea of the consonant had been +firmly grasped, the old syllabary was doomed, though generations of time +might be required to complete the obsequies--generations of time and the +influence of a new nation. We have now to inquire how and by whom this +advance was made. + + +THE ALPHABET ACHIEVED + +We cannot believe that any nation could have vaulted to the final stage +of the simple alphabetical writing without tracing the devious and +difficult way of the pictograph and the syllabary. It is possible, +however, for a cultivated nation to build upon the shoulders of its +neighbors, and, profiting by the experience of others, to make sudden +leaps upward and onward. And this is seemingly what happened in the +final development of the art of writing. For while the Babylonians and +Assyrians rested content with their elaborate syllabary, a nation on +either side of them, geographically speaking, solved the problem, which +they perhaps did not even recognize as a problem; wrested from their +syllabary its secret of consonants and vowels, and by adopting an +arbitrary sign for each consonantal sound, produced that most wonderful +of human inventions, the alphabet. + +The two nations credited with this wonderful achievement are the +Phoenicians and the Persians. But it is not usually conceded that the +two are entitled to anything like equal credit. The Persians, probably +in the time of Cyrus the Great, used certain characters of the +Babylonian script for the construction of an alphabet; but at this time +the Phoenician alphabet had undoubtedly been in use for some centuries, +and it is more than probable that the Persian borrowed his idea of an +alphabet from a Phoenician source. And that, of course, makes all the +difference. Granted the idea of an alphabet, it requires no great reach +of constructive genius to supply a set of alphabetical characters; +though even here, it may be added parenthetically, a study of the +development of alphabets will show that mankind has all along had a +characteristic propensity to copy rather than to invent. + +Regarding the Persian alphabet-maker, then, as a copyist rather than +a true inventor, it remains to turn attention to the Phoenician source +whence, as is commonly believed, the original alphabet which became "the +mother of all existing alphabets" came into being. It must be admitted +at the outset that evidence for the Phoenician origin of this alphabet +is traditional rather than demonstrative. The Phoenicians were the great +traders of antiquity; undoubtedly they were largely responsible for the +transmission of the alphabet from one part of the world to another, once +it had been invented. Too much credit cannot be given them for this; and +as the world always honors him who makes an idea fertile rather than the +originator of the idea, there can be little injustice in continuing +to speak of the Phoenicians as the inventors of the alphabet. But the +actual facts of the case will probably never be known. For aught we +know, it may have been some dreamy-eyed Israelite, some Babylonian +philosopher, some Egyptian mystic, perhaps even some obscure Cretan, +who gave to the hard-headed Phoenician trader this conception of a +dismembered syllable with its all-essential, elemental, wonder-working +consonant. But it is futile now to attempt even to surmise on such +unfathomable details as these. Suffice it that the analysis was made; +that one sign and no more was adopted for each consonantal sound of the +Semitic tongue, and that the entire cumbersome mechanism of the Egyptian +and Babylonian writing systems was rendered obsolescent. These systems +did not yield at once, to be sure; all human experience would have been +set at naught had they done so. They held their own, and much more than +held their own, for many centuries. After the Phoenicians as a nation +had ceased to have importance; after their original script had been +endlessly modified by many alien nations; after the original alphabet +had made the conquest of all civilized Europe and of far outlying +portions of the Orient--the Egyptian and Babylonian scribes continued to +indite their missives in the same old pictographs and syllables. + +The inventive thinker must have been struck with amazement when, after +making the fullest analysis of speech-sounds of which he was capable, +he found himself supplied with only a score or so of symbols. Yet as +regards the consonantal sounds he had exhausted the resources of the +Semitic tongue. As to vowels, he scarcely considered them at all. It +seemed to him sufficient to use one symbol for each consonantal sound. +This reduced the hitherto complex mechanism of writing to so simple a +system that the inventor must have regarded it with sheer delight. On +the other hand, the conservative scholar doubtless thought it distinctly +ambiguous. In truth, it must be admitted that the system was imperfect. +It was a vast improvement on the old syllabary, but it had its +drawbacks. Perhaps it had been made a bit too simple; certainly +it should have had symbols for the vowel sounds as well as for the +consonants. Nevertheless, the vowel-lacking alphabet seems to have taken +the popular fancy, and to this day Semitic people have never supplied +its deficiencies save with certain dots and points. + +Peoples using the Aryan speech soon saw the defect, and the Greeks +supplied symbols for several new sounds at a very early day.(8) But +there the matter rested, and the alphabet has remained imperfect. For +the purposes of the English language there should certainly have been +added a dozen or more new characters. It is clear, for example, that, in +the interest of explicitness, we should have a separate symbol for the +vowel sound in each of the following syllables: bar, bay, bann, ball, to +cite a single illustration. + +There is, to be sure, a seemingly valid reason for not extending +our alphabet, in the fact that in multiplying syllables it would be +difficult to select characters at once easy to make and unambiguous. +Moreover, the conservatives might point out, with telling effect, that +the present alphabet has proved admirably effective for about three +thousand years. Yet the fact that our dictionaries supply diacritical +marks for some thirty vowels sounds to indicate the pronunciation of the +words of our every-day speech, shows how we let memory and guessing +do the work that might reasonably be demanded of a really complete +alphabet. But, whatever its defects, the existing alphabet is a +marvellous piece of mechanism, the result of thousands of years +of intellectual effort. It is, perhaps without exception, the most +stupendous invention of the human intellect within historical times--an +achievement taking rank with such great prehistoric discoveries as the +use of articulate speech, the making of a fire, and the invention of +stone implements, of the wheel and axle, and of picture-writing. It made +possible for the first time that education of the masses upon which all +later progress of civilization was so largely to depend. + + + + +V. THE BEGINNINGS OF GREEK SCIENCE + +Herodotus, the Father of History, tells us that once upon a time--which +time, as the modern computator shows us, was about the year 590 B.C.--a +war had risen between the Lydians and the Medes and continued five +years. "In these years the Medes often discomfited the Lydians and the +Lydians often discomfited the Medes (and among other things they fought +a battle by night); and yet they still carried on the war with equally +balanced fortitude. In the sixth year a battle took place in which it +happened, when the fight had begun, that suddenly the day became night. +And this change of the day Thales, the Milesian, had foretold to the +Ionians, laying down as a limit this very year in which the change took +place. The Lydians, however, and the Medes, when they saw that it had +become night instead of day, ceased from their fighting and were much +more eager, both of them, that peace should be made between them." + +This memorable incident occurred while Alyattus, father of Croesus, +was king of the Lydians. The modern astronomer, reckoning backward, +estimates this eclipse as occurring probably May 25th, 585 B.C. The +date is important as fixing a mile-stone in the chronology of ancient +history, but it is doubly memorable because it is the first recorded +instance of a predicted eclipse. Herodotus, who tells the story, was not +born until about one hundred years after the incident occurred, but time +had not dimmed the fame of the man who had performed the necromantic +feat of prophecy. Thales, the Milesian, thanks in part at least to this +accomplishment, had been known in life as first on the list of the Seven +Wise Men of Greece, and had passed into history as the father of Greek +philosophy. We may add that he had even found wider popular fame through +being named by Hippolytus, and then by Father aesop, as the philosopher +who, intent on studying the heavens, fell into a well; "whereupon," says +Hippolytus, "a maid-servant named Thratta laughed at him and said, 'In +his search for things in the sky he does not see what is at his feet.'" + +Such citations as these serve to bring vividly to mind the fact that +we are entering a new epoch of thought. Hitherto our studies have been +impersonal. Among Egyptians and Babylonians alike we have had to deal +with classes of scientific records, but we have scarcely come across a +single name. Now, however, we shall begin to find records of the work of +individual investigators. In general, from now on, we shall be able to +trace each great idea, if not to its originator, at least to some one +man of genius who was prominent in bringing it before the world. The +first of these vitalizers of thought, who stands out at the beginnings +of Greek history, is this same Thales, of Miletus. His is not a very +sharply defined personality as we look back upon it, and we can by no +means be certain that all the discoveries which are ascribed to him are +specifically his. Of his individuality as a man we know very little. It +is not even quite certain as to where he was born; Miletus is usually +accepted as his birthplace, but one tradition makes him by birth a +Phenician. It is not at all in question, however, that by blood he +was at least in part an Ionian Greek. It will be recalled that in +the seventh century B.C., when Thales was born--and for a long +time thereafter--the eastern shores of the aegean Sea were quite as +prominently the centre of Greek influence as was the peninsula of Greece +itself. Not merely Thales, but his followers and disciples, Anaximander +and Anaximenes, were born there. So also was Herodotas, the Father of +History, not to extend the list. There is nothing anomalous, then, in +the fact that Thales, the father of Greek thought, was born and passed +his life on soil that was not geographically a part of Greece; but +the fact has an important significance of another kind. Thanks to his +environment, Thales was necessarily brought more or less in contact with +Oriental ideas. There was close commercial contact between the land of +his nativity and the great Babylonian capital off to the east, as also +with Egypt. Doubtless this association was of influence in shaping +the development of Thales's mind. Indeed, it was an accepted tradition +throughout classical times that the Milesian philosopher had travelled +in Egypt, and had there gained at least the rudiments of his knowledge +of geometry. In the fullest sense, then, Thales may be regarded as +representing a link in the chain of thought connecting the learning +of the old Orient with the nascent scholarship of the new Occident. +Occupying this position, it is fitting that the personality of Thales +should partake somewhat of mystery; that the scene may not be shifted +too suddenly from the vague, impersonal East to the individualism of +Europe. + +All of this, however, must not be taken as casting any doubt upon the +existence of Thales as a real person. Even the dates of his life--640 to +546 B.C.--may be accepted as at least approximately trustworthy; and the +specific discoveries ascribed to him illustrate equally well the stage +of development of Greek thought, whether Thales himself or one of his +immediate disciples were the discoverer. We have already mentioned the +feat which was said to have given Thales his great reputation. That +Thales was universally credited with having predicted the famous eclipse +is beyond question. That he actually did predict it in any precise sense +of the word is open to doubt. At all events, his prediction was not +based upon any such precise knowledge as that of the modern astronomer. +There is, indeed, only one way in which he could have foretold the +eclipse, and that is through knowledge of the regular succession of +preceding eclipses. But that knowledge implies access on the part of +some one to long series of records of practical observations of the +heavens. Such records, as we have seen, existed in Egypt and even +more notably in Babylonia. That these records were the source of the +information which established the reputation of Thales is an unavoidable +inference. In other words, the magical prevision of the father of Greek +thought was but a reflex of Oriental wisdom. Nevertheless, it sufficed +to establish Thales as the father of Greek astronomy. In point of fact, +his actual astronomical attainments would appear to have been meagre +enough. There is nothing to show that he gained an inkling of the true +character of the solar system. He did not even recognize the sphericity +of the earth, but held, still following the Oriental authorities, that +the world is a flat disk. Even his famous cosmogonic guess, according to +which water is the essence of all things and the primordial element +out of which the earth was developed, is but an elaboration of the +Babylonian conception. + +When we turn to the other field of thought with which the name of Thales +is associated--namely, geometry--we again find evidence of the Oriental +influence. The science of geometry, Herodotus assures us, was invented +in Egypt. It was there an eminently practical science, being applied, as +the name literally suggests, to the measurement of the earth's surface. +Herodotus tells us that the Egyptians were obliged to cultivate +the science because the periodical inundations washed away the +boundary-lines between their farms. The primitive geometer, then, was +a surveyor. The Egyptian records, as now revealed to us, show that the +science had not been carried far in the land of its birth. The +Egyptian geometer was able to measure irregular pieces of land only +approximately. He never fully grasped the idea of the perpendicular +as the true index of measurement for the triangle, but based his +calculations upon measurements of the actual side of that figure. +Nevertheless, he had learned to square the circle with a close +approximation to the truth, and, in general, his measurement sufficed +for all his practical needs. Just how much of the geometrical knowledge +which added to the fame of Thales was borrowed directly from the +Egyptians, and how much he actually created we cannot be sure. Nor is +the question raised in disparagement of his genius. Receptivity is the +first prerequisite to progressive thinking, and that Thales reached out +after and imbibed portions of Oriental wisdom argues in itself for +the creative character of his genius. Whether borrower of originator, +however, Thales is credited with the expression of the following +geometrical truths: + +1. That the circle is bisected by its diameter. + +2. That the angles at the base of an isosceles triangle are equal. + +3. That when two straight lines cut each other the vertical opposite +angles are equal. + +4. That the angle in a semicircle is a right angle. + +5. That one side and one acute angle of a right-angle triangle determine +the other sides of the triangle. + +It was by the application of the last of these principles that Thales is +said to have performed the really notable feat of measuring the distance +of a ship from the shore, his method being precisely the same in +principle as that by which the guns are sighted on a modern man-of-war. +Another practical demonstration which Thales was credited with making, +and to which also his geometrical studies led him, was the measurement +of any tall object, such as a pyramid or building or tree, by means +of its shadow. The method, though simple enough, was ingenious. It +consisted merely in observing the moment of the day when a perpendicular +stick casts a shadow equal to its own length. Obviously the tree or +monument would also cast a shadow equal to its own height at the same +moment. It remains then but to measure the length of this shadow to +determine the height of the object. Such feats as this evidence the +practicality of the genius of Thales. They suggest that Greek science, +guided by imagination, was starting on the high-road of observation. We +are told that Thales conceived for the first time the geometry of lines, +and that this, indeed, constituted his real advance upon the Egyptians. +We are told also that he conceived the eclipse of the sun as a purely +natural phenomenon, and that herein lay his advance upon the Chaldean +point of view. But if this be true Thales was greatly in advance of his +time, for it will be recalled that fully two hundred years later +the Greeks under Nicias before Syracuse were so disconcerted by the +appearance of an eclipse, which was interpreted as a direct omen and +warning, that Nicias threw away the last opportunity to rescue his army. +Thucydides, it is true, in recording this fact speaks disparagingly of +the superstitious bent of the mind of Nicias, but Thucydides also was a +man far in advance of his time. + +All that we know of the psychology of Thales is summed up in the famous +maxim, "Know thyself," a maxim which, taken in connection with +the proven receptivity of the philosopher's mind, suggests to us a +marvellously rounded personality. + +The disciples or successors of Thales, Anaximander and Anaximenes, were +credited with advancing knowledge through the invention or introduction +of the sundial. We may be sure, however, that the gnomon, which is the +rudimentary sundial, had been known and used from remote periods in +the Orient, and the most that is probable is that Anaximander may +have elaborated some special design, possibly the bowl-shaped sundial, +through which the shadow of the gnomon would indicate the time. The same +philosopher is said to have made the first sketch of a geographical map, +but this again is a statement which modern researches have shown to be +fallacious, since a Babylonian attempt at depicting the geography of +the world is still preserved to us on a clay tablet. Anaximander may, +however, have been the first Greek to make an attempt of this kind. Here +again the influence of Babylonian science upon the germinating Western +thought is suggested. + +It is said that Anaximander departed from Thales's conception of the +earth, and, it may be added, from the Babylonian conception also, in +that he conceived it as a cylinder, or rather as a truncated cone, the +upper end of which is the habitable portion. This conception is perhaps +the first of these guesses through which the Greek mind attempted to +explain the apparent fixity of the earth. To ask what supports the earth +in space is most natural, but the answer given by Anaximander, like that +more familiar Greek solution which transformed the cone, or cylinder, +into the giant Atlas, is but another illustration of that substitution +of unwarranted inference for scientific induction which we have already +so often pointed out as characteristic of the primitive stages of +thought. + +Anaximander held at least one theory which, as vouched for by various +copyists and commentators, entitles him to be considered perhaps the +first teacher of the idea of organic evolution. According to this idea, +man developed from a fishlike ancestor, "growing up as sharks do until +able to help himself and then coming forth on dry land."(1) The thought +here expressed finds its germ, perhaps, in the Babylonian conception +that everything came forth from a chaos of waters. Yet the fact that the +thought of Anaximander has come down to posterity through such various +channels suggests that the Greek thinker had got far enough away from +the Oriental conception to make his view seem to his contemporaries a +novel and individual one. Indeed, nothing we know of the Oriental line +of thought conveys any suggestion of the idea of transformation of +species, whereas that idea is distinctly formulated in the traditional +views of Anaximander. + + + + +VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +Diogenes Laertius tells a story about a youth who, clad in a purple +toga, entered the arena at the Olympian games and asked to compete +with the other youths in boxing. He was derisively denied admission, +presumably because he was beyond the legitimate age for juvenile +contestants. Nothing daunted, the youth entered the lists of men, and +turned the laugh on his critics by coming off victor. The youth who +performed this feat was named Pythagoras. He was the same man, if we +may credit the story, who afterwards migrated to Italy and became +the founder of the famous Crotonian School of Philosophy; the man who +developed the religion of the Orphic mysteries; who conceived the +idea of the music of the spheres; who promulgated the doctrine of +metempsychosis; who first, perhaps, of all men clearly conceived the +notion that this world on which we live is a ball which moves in space +and which may be habitable on every side. + +A strange development that for a stripling pugilist. But we must not +forget that in the Greek world athletics held a peculiar place. The +chief winner of Olympian games gave his name to an epoch (the ensuing +Olympiad of four years), and was honored almost before all others in the +land. A sound mind in a sound body was the motto of the day. To excel +in feats of strength and dexterity was an accomplishment that even +a philosopher need not scorn. It will be recalled that aeschylus +distinguished himself at the battle of Marathon; that Thucydides, the +greatest of Greek historians, was a general in the Peloponnesian War; +that Xenophon, the pupil and biographer of Socrates, was chiefly famed +for having led the Ten Thousand in the memorable campaign of Cyrus +the Younger; that Plato himself was credited with having shown +great aptitude in early life as a wrestler. If, then, Pythagoras the +philosopher was really the Pythagoras who won the boxing contest, we may +suppose that in looking back upon this athletic feat from the heights of +his priesthood--for he came to be almost deified--he regarded it not as +an indiscretion of his youth, but as one of the greatest achievements of +his life. Not unlikely he recalled with pride that he was credited +with being no less an innovator in athletics than in philosophy. At all +events, tradition credits him with the invention of "scientific" +boxing. Was it he, perhaps, who taught the Greeks to strike a rising +and swinging blow from the hip, as depicted in the famous metopes of the +Parthenon? If so, the innovation of Pythagoras was as little heeded in +this regard in a subsequent age as was his theory of the motion of the +earth; for to strike a swinging blow from the hip, rather than from the +shoulder, is a trick which the pugilist learned anew in our own day. + +But enough of pugilism and of what, at best, is a doubtful tradition. +Our concern is with another "science" than that of the arena. We +must follow the purple-robed victor to Italy--if, indeed, we be not +over-credulous in accepting the tradition--and learn of triumphs of a +different kind that have placed the name of Pythagoras high on the list +of the fathers of Grecian thought. To Italy? Yes, to the western limits +of the Greek world. Here it was, beyond the confines of actual Greek +territory, that Hellenic thought found its second home, its first home +being, as we have seen, in Asia Minor. Pythagoras, indeed, to whom we +have just been introduced, was born on the island of Samos, which lies +near the coast of Asia Minor, but he probably migrated at an early +day to Crotona, in Italy. There he lived, taught, and developed +his philosophy until rather late in life, when, having incurred the +displeasure of his fellow-citizens, he suffered the not unusual penalty +of banishment. + +Of the three other great Italic leaders of thought of the early period, +Xenophanes came rather late in life to Elea and founded the famous +Eleatic School, of which Parmenides became the most distinguished +ornament. These two were Ionians, and they lived in the sixth century +before our era. Empedocles, the Sicilian, was of Doric origin. He lived +about the middle of the fifth century B.C., at a time, therefore, when +Athens had attained a position of chief glory among the Greek states; +but there is no evidence that Empedocles ever visited that city, though +it was rumored that he returned to the Peloponnesus to die. The other +great Italic philosophers just named, living, as we have seen, in the +previous century, can scarcely have thought of Athens as a centre of +Greek thought. Indeed, the very fact that these men lived in Italy made +that peninsula, rather than the mother-land of Greece, the centre of +Hellenic influence. But all these men, it must constantly be borne in +mind, were Greeks by birth and language, fully recognized as such in +their own time and by posterity. Yet the fact that they lived in a land +which was at no time a part of the geographical territory of Greece must +not be forgotten. They, or their ancestors of recent generations, had +been pioneers among those venturesome colonists who reached out into +distant portions of the world, and made homes for themselves in much +the same spirit in which colonists from Europe began to populate America +some two thousand years later. In general, colonists from the different +parts of Greece localized themselves somewhat definitely in their new +homes; yet there must naturally have been a good deal of commingling +among the various families of pioneers, and, to a certain extent, a +mingling also with the earlier inhabitants of the country. This racial +mingling, combined with the well-known vitalizing influence of the +pioneer life, led, we may suppose, to a more rapid and more varied +development than occurred among the home-staying Greeks. In proof of +this, witness the remarkable schools of philosophy which, as we have +seen, were thus developed at the confines of the Greek world, and +which were presently to invade and, as it were, take by storm the +mother-country itself. + +As to the personality of these pioneer philosophers of the West, our +knowledge is for the most part more or less traditional. What has been +said of Thales may be repeated, in the main, regarding Pythagoras, +Parmenides, and Empedocles. That they were real persons is not at all in +question, but much that is merely traditional has come to be associated +with their names. Pythagoras was the senior, and doubtless his ideas may +have influenced the others more or less, though each is usually spoken +of as the founder of an independent school. Much confusion has all along +existed, however, as to the precise ideas which were to be ascribed to +each of the leaders. Numberless commentators, indeed, have endeavored +to pick out from among the traditions of antiquity, aided by such +fragments, of the writing of the philosophers as have come down to us, +the particular ideas that characterized each thinker, and to weave these +ideas into systems. But such efforts, notwithstanding the mental energy +that has been expended upon them, were, of necessity, futile, since, in +the first place, the ancient philosophers themselves did not specialize +and systematize their ideas according to modern notions, and, in the +second place, the records of their individual teachings have been too +scantily preserved to serve for the purpose of classification. It +is freely admitted that fable has woven an impenetrable mesh of +contradictions about the personalities of these ancient thinkers, and it +would be folly to hope that this same artificer had been less busy with +their beliefs and theories. When one reads that Pythagoras advocated an +exclusively vegetable diet, yet that he was the first to train athletes +on meat diet; that he sacrificed only inanimate things, yet that he +offered up a hundred oxen in honor of his great discovery regarding +the sides of a triangle, and such like inconsistencies in the same +biography, one gains a realizing sense of the extent to which diverse +traditions enter into the story as it has come down to us. And yet we +must reflect that most men change their opinions in the course of a long +lifetime, and that the antagonistic reports may both be true. + +True or false, these fables have an abiding interest, since they prove +the unique and extraordinary character of the personality about which +they are woven. The alleged witticisms of a Whistler, in our own day, +were doubtless, for the most part, quite unknown to Whistler himself, +yet they never would have been ascribed to him were they not akin to +witticisms that he did originate--were they not, in short, typical +expressions of his personality. And so of the heroes of the past. "It is +no ordinary man," said George Henry Lewes, speaking of Pythagoras, +"whom fable exalts into the poetic region. Whenever you find romantic or +miraculous deeds attributed, be certain that the hero was great enough +to maintain the weight of the crown of this fabulous glory."(1) We may +not doubt, then, that Pythagoras, Parmenides, and Empedocles, with whose +names fable was so busy throughout antiquity, were men of extraordinary +personality. We are here chiefly concerned, however, neither with the +personality of the man nor yet with the precise doctrines which each one +of them taught. A knowledge of the latter would be interesting were it +attainable, but in the confused state of the reports that have come down +to us we cannot hope to be able to ascribe each idea with precision +to its proper source. At best we can merely outline, even here not too +precisely, the scientific doctrines which the Italic philosophers as a +whole seem to have advocated. + +First and foremost, there is the doctrine that the earth is a sphere. +Pythagoras is said to have been the first advocate of this theory; but, +unfortunately, it is reported also that Parmenides was its author. This +rivalship for the discovery of an important truth we shall see repeated +over and over in more recent times. Could we know the whole truth, it +would perhaps appear that the idea of the sphericity of the earth was +originated long before the time of the Greek philosophers. But it must +be admitted that there is no record of any sort to give tangible support +to such an assumption. So far as we can ascertain, no Egyptian or +Babylonian astronomer ever grasped the wonderful conception that the +earth is round. That the Italic Greeks should have conceived that idea +was perhaps not so much because they were astronomers as because they +were practical geographers and geometers. Pythagoras, as we have noted, +was born at Samos, and, therefore, made a relatively long sea voyage in +passing to Italy. Now, as every one knows, the most simple and tangible +demonstration of the convexity of the earth's surface is furnished by +observation of an approaching ship at sea. On a clear day a keen eye +may discern the mast and sails rising gradually above the horizon, to be +followed in due course by the hull. Similarly, on approaching the shore, +high objects become visible before those that lie nearer the water. It +is at least a plausible supposition that Pythagoras may have made such +observations as these during the voyage in question, and that therein +may lie the germ of that wonderful conception of the world as a sphere. + +To what extent further proof, based on the fact that the earth's shadow +when the moon is eclipsed is always convex, may have been known to +Pythagoras we cannot say. There is no proof that any of the Italic +philosophers made extensive records of astronomical observations as did +the Egyptians and Babylonians; but we must constantly recall that the +writings of classical antiquity have been almost altogether destroyed. +The absence of astronomical records is, therefore, no proof that such +records never existed. Pythagoras, it should be said, is reported to +have travelled in Egypt, and he must there have gained an inkling of +astronomical methods. Indeed, he speaks of himself specifically, in a +letter quoted by Diogenes, as one who is accustomed to study astronomy. +Yet a later sentence of the letter, which asserts that the philosopher +is not always occupied about speculations of his own fancy, suggesting, +as it does, the dreamer rather than the observer, gives us probably a +truer glimpse into the philosopher's mind. There is, indeed, reason to +suppose that the doctrine of the sphericity of the earth appealed to +Pythagoras chiefly because it accorded with his conception that the +sphere is the most perfect solid, just as the circle is the most perfect +plane surface. Be that as it may, the fact remains that we have here, as +far as we can trace its origin, the first expression of the scientific +theory that the earth is round. Had the Italic philosophers accomplished +nothing more than this, their accomplishment would none the less mark an +epoch in the progress of thought. + +That Pythagoras was an observer of the heavens is further evidenced by +the statement made by Diogenes, on the authority of Parmenides, that +Pythagoras was the first person who discovered or asserted the identity +of Hesperus and Lucifer--that is to say, of the morning and the evening +star. This was really a remarkable discovery, and one that was no doubt +instrumental later on in determining that theory of the mechanics of +the heavens which we shall see elaborated presently. To have made such +a discovery argues again for the practicality of the mind of Pythagoras. +His, indeed, would seem to have been a mind in which practical +common-sense was strangely blended with the capacity for wide and +imaginative generalization. As further evidence of his practicality, +it is asserted that he was the first person who introduced measures and +weights among the Greeks, this assertion being made on the authority of +Aristoxenus. It will be observed that he is said to have introduced, +not to have invented, weights and measures, a statement which suggests +a knowledge on the part of the Greeks that weights and measures were +previously employed in Egypt and Babylonia. + +The mind that could conceive the world as a sphere and that interested +itself in weights and measures was, obviously, a mind of the visualizing +type. It is characteristic of this type of mind to be interested in the +tangibilities of geometry, hence it is not surprising to be told +that Pythagoras "carried that science to perfection." The most famous +discovery of Pythagoras in this field was that the square of the +hypotenuse of a right-angled triangle is equal to the squares of the +other sides of the triangle. We have already noted the fable that +his enthusiasm over this discovery led him to sacrifice a hecatomb. +Doubtless the story is apocryphal, but doubtless, also, it expresses +the truth as to the fervid joy with which the philosopher must have +contemplated the results of his creative imagination. + +No line alleged to have been written by Pythagoras has come down to us. +We are told that he refrained from publishing his doctrines, except by +word of mouth. "The Lucanians and the Peucetians, and the Messapians and +the Romans," we are assured, "flocked around him, coming with eagerness +to hear his discourses; no fewer than six hundred came to him every +night; and if any one of them had ever been permitted to see the master, +they wrote of it to their friends as if they had gained some great +advantage." Nevertheless, we are assured that until the time of +Philolaus no doctrines of Pythagoras were ever published, to which +statement it is added that "when the three celebrated books were +published, Plato wrote to have them purchased for him for a hundred +minas."(2) But if such books existed, they are lost to the modern world, +and we are obliged to accept the assertions of relatively late writers +as to the theories of the great Crotonian. + +Perhaps we cannot do better than quote at length from an important +summary of the remaining doctrines of Pythagoras, which Diogenes himself +quoted from the work of a predecessor.(3) Despite its somewhat inchoate +character, this summary is a most remarkable one, as a brief analysis +of its contents will show. It should be explained that Alexander (whose +work is now lost) is said to have found these dogmas set down in the +commentaries of Pythagoras. If this assertion be accepted, we are +brought one step nearer the philosopher himself. The summary is as +follows: + + +"That the monad was the beginning of everything. From the monad proceeds +an indefinite duad, which is subordinate to the monad as to its cause. +That from the monad and the indefinite duad proceed numbers. And +from numbers signs. And from these last, lines of which plane figures +consist. And from plane figures are derived solid bodies. And from solid +bodies sensible bodies, of which last there are four elements--fire, +water, earth, and air. And that the world, which is indued with life and +intellect, and which is of a spherical figure, having the earth, which +is also spherical, and inhabited all over in its centre,(4) results from +a combination of these elements, and derives its motion from them; and +also that there are antipodes, and that what is below, as respects us, +is above in respect of them. + +"He also taught that light and darkness, and cold and heat, and dryness +and moisture, were equally divided in the world; and that while heat was +predominant it was summer; while cold had the mastery, it was winter; +when dryness prevailed, it was spring; and when moisture preponderated, +winter. And while all these qualities were on a level, then was the +loveliest season of the year; of which the flourishing spring was the +wholesome period, and the season of autumn the most pernicious one. Of +the day, he said that the flourishing period was the morning, and the +fading one the evening; on which account that also was the least healthy +time. + +"Another of his theories was that the air around the earth was immovable +and pregnant with disease, and that everything in it was mortal; but +that the upper air was in perpetual motion, and pure and salubrious, and +that everything in that was immortal, and on that account divine. And +that the sun and the moon and the stars were all gods; for in them the +warm principle predominates which is the cause of life. And that the +moon derives its light from the sun. And that there is a relationship +between men and the gods, because men partake of the divine principle; +on which account, also, God exercises his providence for our advantage. +Also, that Fate is the cause of the arrangement of the world both +generally and particularly. Moreover, that a ray from the sun penetrated +both the cold aether and the dense aether; and they call the air the +cold aether, and the sea and moisture they call the dense aether. And +this ray descends into the depths, and in this way vivifies everything. +And everything which partakes of the principle of heat lives, on which +account, also, plants are animated beings; but that all living things +have not necessarily souls. And that the soul is a something tom off +from the aether, both warm and cold, from its partaking of the cold +aether. And that the soul is something different from life. Also, +that it is immortal, because that from which it has been detached is +immortal. + +"Also, that animals are born from one another by seeds, and that it is +impossible for there to be any spontaneous production by the earth. +And that seed is a drop from the brain which contains in itself a warm +vapor; and that when this is applied to the womb it transmits virtue and +moisture and blood from the brain, from which flesh and sinews and bones +and hair and the whole body are produced. And from the vapor is produced +the soul, and also sensation. And that the infant first becomes a solid +body at the end of forty days; but, according to the principles of +harmony, it is not perfect till seven, or perhaps nine, or at most ten +months, and then it is brought forth. And that it contains in itself all +the principles of life, which are all connected together, and by their +union and combination form a harmonious whole, each of them developing +itself at the appointed time. + +"The senses in general, and especially the sight, are a vapor of +excessive warmth, and on this account a man is said to see through air +and through water. For the hot principle is opposed by the cold one; +since, if the vapor in the eyes were cold, it would have the same +temperature as the air, and so would be dissipated. As it is, in some +passages he calls the eyes the gates of the sun; and he speaks in a +similar manner of hearing and of the other senses. + +"He also says that the soul of man is divided into three parts: into +intuition and reason and mind, and that the first and last divisions are +found also in other animals, but that the middle one, reason, is only +found in man. And that the chief abode of the soul is in those parts +of the body which are between the heart and the brain. And that that +portion of it which is in the heart is the mind; but that deliberation +and reason reside in the brain. + +"Moreover, that the senses are drops from them; and that the reasoning +sense is immortal, but the others are mortal. And that the soul is +nourished by the blood; and that reasons are the winds of the soul. +That it is invisible, and so are its reasons, since the aether itself is +invisible. That the links of the soul are the veins and the arteries +and the nerves. But that when it is vigorous, and is by itself in a +quiescent state, then its links are words and actions. That when it +is cast forth upon the earth it wanders about, resembling the body. +Moreover, that Mercury is the steward of the souls, and that on this +account he has the name of Conductor, and Commercial, and Infernal, +since it is he who conducts the souls from their bodies, and from earth +and sea; and that he conducts the pure souls to the highest region, and +that he does not allow the impure ones to approach them, nor to come +near one another, but commits them to be bound in indissoluble fetters +by the Furies. The Pythagoreans also assert that the whole air is full +of souls, and that these are those which are accounted daemons and +heroes. Also, that it is by them that dreams are sent among men, and +also the tokens of disease and health; these last, too, being sent not +only to men, but to sheep also, and other cattle. Also that it is they +who are concerned with purifications and expiations and all kinds of +divination and oracular predictions, and things of that kind."(5) + + +A brief consideration of this summary of the doctrines of Pythagoras +will show that it at least outlines a most extraordinary variety of +scientific ideas. (1) There is suggested a theory of monads and the +conception of the development from simple to more complex bodies, +passing through the stages of lines, plain figures, and solids to +sensible bodies. (2) The doctrine of the four elements--fire, water, +earth, and air--as the basis of all organisms is put forward. (3) +The idea, not merely of the sphericity of the earth, but an explicit +conception of the antipodes, is expressed. (4) A conception of the +sanitary influence of the air is clearly expressed. (5) An idea of the +problems of generation and heredity is shown, together with a distinct +disavowal of the doctrine of spontaneous generation--a doctrine which, +it may be added, remained in vogue, nevertheless, for some twenty-four +hundred years after the time of Pythagoras. (6) A remarkable analysis of +mind is made, and a distinction between animal minds and the human mind +is based on this analysis. The physiological doctrine that the heart +is the organ of one department of mind is offset by the clear statement +that the remaining factors of mind reside in the brain. This early +recognition of brain as the organ of mind must not be forgotten in +our later studies. It should be recalled, however, that a Crotonian +physician, Alemaean, a younger contemporary of Pythagoras, is also +credited with the same theory. (7) A knowledge of anatomy is at least +vaguely foreshadowed in the assertion that veins, arteries, and nerves +are the links of the soul. In this connection it should be recalled that +Pythagoras was a practical physician. + +As against these scientific doctrines, however, some of them being at +least remarkable guesses at the truth, attention must be called to +the concluding paragraph of our quotation, in which the old familiar +daemonology is outlined, quite after the Oriental fashion. We shall have +occasion to say more as to this phase of the subject later on. Meantime, +before leaving Pythagoras, let us note that his practical studies of +humanity led him to assert the doctrine that "the property of friends +is common, and that friendship is equality." His disciples, we are told, +used to put all their possessions together in one store and use them in +common. Here, then, seemingly, is the doctrine of communism put to the +test of experiment at this early day. If it seem that reference to +this carries us beyond the bounds of science, it may be replied that +questions such as this will not lie beyond the bounds of the science of +the near future. + + +XENOPHANES AND PARMENIDES + +There is a whimsical tale about Pythagoras, according to which the +philosopher was wont to declare that in an earlier state he had visited +Hades, and had there seen Homer and Hesiod tortured because of the +absurd things they had said about the gods. Apocrypbal or otherwise, +the tale suggests that Pythagoras was an agnostic as regards the current +Greek religion of his time. The same thing is perhaps true of most +of the great thinkers of this earliest period. But one among them was +remembered in later times as having had a peculiar aversion to the +anthropomorphic conceptions of his fellows. This was Xenophanes, who was +born at Colophon probably about the year 580 B.C., and who, after a life +of wandering, settled finally in Italy and became the founder of the +so-called Eleatic School. + +A few fragments of the philosophical poem in which Xenophanes expressed +his views have come down to us, and these fragments include a tolerably +definite avowal of his faith. "God is one supreme among gods and men, +and not like mortals in body or in mind," says Xenophanes. Again he +asserts that "mortals suppose that the gods are born (as they themselves +are), that they wear man's clothing and have human voice and body; but," +he continues, "if cattle or lions had hands so as to paint with their +hands and produce works of art as men do, they would paint their gods +and give them bodies in form like their own--horses like horses, cattle +like cattle." Elsewhere he says, with great acumen: "There has not been +a man, nor will there be, who knows distinctly what I say about the gods +or in regard to all things. For even if one chance for the most part to +say what is true, still he would not know; but every one thinks that he +knows."(6) + +In the same spirit Xenophanes speaks of the battles of Titans, of +giants, and of centaurs as "fictions of former ages." All this tells of +the questioning spirit which distinguishes the scientific investigator. +Precisely whither this spirit led him we do not know, but the writers of +a later time have preserved a tradition regarding a belief of Xenophanes +that perhaps entitles him to be considered the father of geology. Thus +Hippolytus records that Xenophanes studied the fossils to be found in +quarries, and drew from their observation remarkable conclusions. His +words are as follows: "Xenophanes believes that once the earth was +mingled with the sea, but in the course of time it became freed from +moisture; and his proofs are such as these: that shells are found in +the midst of the land and among the mountains, that in the quarries +of Syracuse the imprints of a fish and of seals had been found, and +in Paros the imprint of an anchovy at some depth in the stone, and in +Melite shallow impressions of all sorts of sea products. He says that +these imprints were made when everything long ago was covered with mud, +and then the imprint dried in the mud. Further, he says that all men +will be destroyed when the earth sinks into the sea and becomes mud, +and that the race will begin anew from the beginning; and this +transformation takes place for all worlds."(7) Here, then, we see this +earliest of paleontologists studying the fossil-bearing strata of the +earth, and drawing from his observations a marvellously scientific +induction. Almost two thousand years later another famous citizen +of Italy, Leonardo da Vinci, was independently to think out similar +conclusions from like observations. But not until the nineteenth century +of our era, some twenty-four hundred years after the time of Xenophanes, +was the old Greek's doctrine to be accepted by the scientific world. +The ideas of Xenophanes were known to his contemporaries and, as we see, +quoted for a few centuries by his successors, then they were ignored +or quite forgotten; and if any philosopher of an ensuing age before the +time of Leonardo championed a like rational explanation of the fossils, +we have no record of the fact. The geological doctrine of Xenophanes, +then, must be listed among those remarkable Greek anticipations of +nineteenth-century science which suffered almost total eclipse in the +intervening centuries. + +Among the pupils of Xenophanes was Parmenides, the thinker who was +destined to carry on the work of his master along the same scientific +lines, though at the same time mingling his scientific conceptions with +the mysticism of the poet. We have already had occasion to mention that +Parmenides championed the idea that the earth is round; noting also that +doubts exist as to whether he or Pythagoras originated this doctrine. +No explicit answer to this question can possibly be hoped for. It seems +clear, however, that for a long time the Italic School, to which both +these philosophers belonged, had a monopoly of the belief in question. +Parmenides, like Pythagoras, is credited with having believed in the +motion of the earth, though the evidence furnished by the writings +of the philosopher himself is not as demonstrative as one could wish. +Unfortunately, the copyists of a later age were more concerned with +metaphysical speculations than with more tangible things. But as far as +the fragmentary references to the ideas of Parmenides may be accepted, +they do not support the idea of the earth's motion. Indeed, Parmenides +is made to say explicitly, in preserved fragments, that "the world is +immovable, limited, and spheroidal in form."(8) + +Nevertheless, some modern interpreters have found an opposite meaning in +Parmenides. Thus Ritter interprets him as supposing "that the earth +is in the centre spherical, and maintained in rotary motion by its +equiponderance; around it lie certain rings, the highest composed of the +rare element fire, the next lower a compound of light and darkness, and +lowest of all one wholly of night, which probably indicated to his +mind the surface of the earth, the centre of which again he probably +considered to be fire."(9) But this, like too many interpretations of +ancient thought, appears to read into the fragments ideas which the +words themselves do not warrant. There seems no reason to doubt, +however, that Parmenides actually held the doctrine of the earth's +sphericity. Another glimpse of his astronomical doctrines is furnished +us by a fragment which tells us that he conceived the morning and the +evening stars to be the same, a doctrine which, as we have seen, was +ascribed also to Pythagoras. Indeed, we may repeat that it is quite +impossible to distinguish between the astronomical doctrines of these +two philosophers. + +The poem of Parmenides in which the cosmogonic speculations occur +treats also of the origin of man. The author seems to have had a clear +conception that intelligence depends on bodily organism, and that the +more elaborately developed the organism the higher the intelligence. +But in the interpretation of this thought we are hampered by the +characteristic vagueness of expression, which may best be evidenced by +putting before the reader two English translations of the same stanza. +Here is Ritter's rendering, as made into English by his translator, +Morrison: + + "For exactly as each has the state of his limbs many-jointed, +So invariably stands it with men in their mind and their reason; For the +system of limbs is that which thinketh in mankind Alike in all and in +each: for thought is the fulness."(10) + +The same stanza is given thus by George Henry Lewes: + + "Such as to each man is the nature of his many-jointed limbs, +Such also is the intelligence of each man; for it is The nature of limbs +(organization) which thinketh in men, Both in one and in all; for the +highest degree of organization gives the highest degree of thought."(11) + + +Here it will be observed that there is virtual agreement between the +translators except as to the last clause, but that clause is most +essential. The Greek phrase is (gr to gar pleon esti nohma). Ritter, +it will be observed, renders this, "for thought is the fulness." Lewes +paraphrases it, "for the highest degree of organization gives the +highest degree of thought." The difference is intentional, since Lewes +himself criticises the translation of Ritter. Ritter's translation is +certainly the more literal, but the fact that such diversity is possible +suggests one of the chief elements of uncertainty that hamper our +interpretation of the thought of antiquity. Unfortunately, the mind +of the commentator has usually been directed towards such subtleties, +rather than towards the expression of precise knowledge. Hence it is +that the philosophers of Greece are usually thought of as mere dreamers, +and that their true status as scientific discoverers is so often +overlooked. With these intangibilities we have no present concern beyond +this bare mention; for us it suffices to gain as clear an idea as we +may of the really scientific conceptions of these thinkers, leaving the +subtleties of their deductive reasoning for the most part untouched. + + +EMPEDOCLES + +The latest of the important pre-Socratic philosophers of the Italic +school was Empedocles, who was born about 494 B.C. and lived to the +age of sixty. These dates make Empedocles strictly contemporary with +Anaxagoras, a fact which we shall do well to bear in mind when we come +to consider the latter's philosophy in the succeeding chapter. Like +Pythagoras, Empedocles is an imposing figure. Indeed, there is much of +similarity between the personalities, as between the doctrines, of the +two men. Empedocles, like Pythagoras, was a physician; like him also he +was the founder of a cult. As statesman, prophet, physicist, physician, +reformer, and poet he showed a versatility that, coupled with +profundity, marks the highest genius. In point of versatility we +shall perhaps hardly find his equal at a later day--unless, indeed, an +exception be made of Eratosthenes. The myths that have grown about the +name of Empedocles show that he was a remarkable personality. He is +said to have been an awe-inspiring figure, clothing himself in Oriental +splendor and moving among mankind as a superior being. Tradition has it +that he threw himself into the crater of a volcano that his otherwise +unexplained disappearance might lead his disciples to believe that he +had been miraculously translated; but tradition goes on to say that one +of the brazen slippers of the philosopher was thrown up by the volcano, +thus revealing his subterfuge. Another tradition of far more credible +aspect asserts that Empedocles retreated from Italy, returning to the +home of his fathers in Peloponnesus to die there obscurely. It seems +odd that the facts regarding the death of so great a man, at so +comparatively late a period, should be obscure; but this, perhaps, is +in keeping with the personality of the man himself. His disciples would +hesitate to ascribe a merely natural death to so inspired a prophet. + +Empedocles appears to have been at once an observer and a dreamer. He is +credited with noting that the pressure of air will sustain the weight +of water in an inverted tube; with divining, without the possibility of +proof, that light has actual motion in space; and with asserting that +centrifugal motion must keep the heavens from falling. He is credited +with a great sanitary feat in the draining of a marsh, and his knowledge +of medicine was held to be supernatural. Fortunately, some fragments of +the writings of Empedocles have come down to us, enabling us to judge +at first hand as to part of his doctrines; while still more is known +through the references made to him by Plato, Aristotle, and other +commentators. Empedocles was a poet whose verses stood the test of +criticism. In this regard he is in a like position with Parmenides; +but in neither case are the preserved fragments sufficient to enable us +fully to estimate their author's scientific attainments. Philosophical +writings are obscure enough at the best, and they perforce become doubly +so when expressed in verse. Yet there are certain passages of Empedocles +that are unequivocal and full of interest. Perhaps the most important +conception which the works of Empedocles reveal to us is the denial +of anthropomorphism as applied to deity. We have seen how early the +anthropomorphic conception was developed and how closely it was all +along clung to; to shake the mind free from it then was a remarkable +feat, in accomplishing which Empedocles took a long step in the +direction of rationalism. His conception is paralleled by that of +another physician, Alcmaeon, of Proton, who contended that man's +ideas of the gods amounted to mere suppositions at the very most. +A rationalistic or sceptical tendency has been the accompaniment of +medical training in all ages. + +The words in which Empedocles expresses his conception of deity have +been preserved and are well worth quoting: "It is not impossible," he +says, "to draw near (to god) even with the eyes or to take hold of him +with our hands, which in truth is the best highway of persuasion in +the mind of man; for he has no human head fitted to a body, nor do two +shoots branch out from the trunk, nor has he feet, nor swift legs, nor +hairy parts, but he is sacred and ineffable mind alone, darting through +the whole world with swift thoughts."(8) + +How far Empedocles carried his denial of anthropomorphism is illustrated +by a reference of Aristotle, who asserts "that Empedocles regards god as +most lacking in the power of perception; for he alone does not know one +of the elements, Strife (hence), of perishable things." It is difficult +to avoid the feeling that Empedocles here approaches the modern +philosophical conception that God, however postulated as immutable, must +also be postulated as unconscious, since intelligence, as we know it, +is dependent upon the transmutations of matter. But to urge this thought +would be to yield to that philosophizing tendency which has been the +bane of interpretation as applied to the ancient thinkers. + +Considering for a moment the more tangible accomplishments of +Empedocles, we find it alleged that one of his "miracles" consisted +of the preservation of a dead body without putrefaction for some weeks +after death. We may assume from this that he had gained in some way a +knowledge of embalming. As he was notoriously fond of experiment, and +as the body in question (assuming for the moment the authenticity of +the legend) must have been preserved without disfigurement, it is +conceivable even that he had hit upon the idea of injecting the +arteries. This, of course, is pure conjecture; yet it finds a certain +warrant, both in the fact that the words of Pythagoras lead us to +believe that the arteries were known and studied, and in the fact that +Empedocles' own words reveal him also as a student of the vascular +system. Thus Plutarch cites Empedocles as believing "that the ruling +part is not in the head or in the breast, but in the blood; wherefore +in whatever part of the body the more of this is spread in that part men +excel."(13) And Empedocles' own words, as preserved by Stobaeus, assert +"(the heart) lies in seas of blood which dart in opposite directions, +and there most of all intelligence centres for men; for blood about the +heart is intelligence in the case of man." All this implies a really +remarkable appreciation of the dependence of vital activities upon the +blood. + +This correct physiological conception, however, was by no means the most +remarkable of the ideas to which Empedoeles was led by his anatomical +studies. His greatest accomplishment was to have conceived and clearly +expressed an idea which the modern evolutionist connotes when he speaks +of homologous parts--an idea which found a famous modern expositor in +Goethe, as we shall see when we come to deal with eighteenth-century +science. Empedocles expresses the idea in these words: "Hair, and +leaves, and thick feathers of birds, are the same thing in origin, and +reptile scales too on strong limbs. But on hedgehogs sharp-pointed hair +bristles on their backs."(14) That the idea of transmutation of +parts, as well as of mere homology, was in mind is evidenced by a very +remarkable sentence in which Aristotle asserts, "Empedocles says that +fingernails rise from sinew from hardening." Nor is this quite all, +for surely we find the germ of the Lamarckian conception of evolution +through the transmission of acquired characters in the assertion that +"many characteristics appear in animals because it happened to be thus +in their birth, as that they have such a spine because they happen to be +descended from one that bent itself backward."(15) Aristotle, in +quoting this remark, asserts, with the dogmatism which characterizes the +philosophical commentators of every age, that "Empedocles is wrong," in +making this assertion; but Lamarck, who lived twenty-three hundred years +after Empedocles, is famous in the history of the doctrine of evolution +for elaborating this very idea. + +It is fair to add, however, that the dreamings of Empedocles regarding +the origin of living organisms led him to some conceptions that were +much less luminous. On occasion, Empedocles the poet got the better +of Empedocles the scientist, and we are presented with a conception of +creation as grotesque as that which delighted the readers of Paradise +Lost at a later day. Empedocles assures us that "many heads grow up +without necks, and arms were wandering about, necks bereft of shoulders, +and eyes roamed about alone with no foreheads."(16) This chaotic +condition, so the poet dreamed, led to the union of many incongruous +parts, producing "creatures with double faces, offspring of oxen with +human faces, and children of men with oxen heads." But out of this chaos +came, finally, we are led to infer, a harmonious aggregation of parts, +producing ultimately the perfected organisms that we see. Unfortunately +the preserved portions of the writings of Empedocles do not enlighten +us as to the precise way in which final evolution was supposed to be +effected; although the idea of endless experimentation until natural +selection resulted in survival of the fittest seems not far afield from +certain of the poetical assertions. Thus: "As divinity was mingled +yet more with divinity, these things (the various members) kept coming +together in whatever way each might chance." Again: "At one time all the +limbs which form the body united into one by love grew vigorously in the +prime of life; but yet at another time, separated by evil Strife, they +wander each in different directions along the breakers of the sea of +life. Just so is it with plants, and with fishes dwelling in watery +halls, and beasts whose lair is in the mountains, and birds borne on +wings."(17) + +All this is poetry rather than science, yet such imaginings could come +only to one who was groping towards what we moderns should term an +evolutionary conception of the origins of organic life; and however +grotesque some of these expressions may appear, it must be admitted +that the morphological ideas of Empedocles, as above quoted, give the +Sicilian philosopher a secure place among the anticipators of the modern +evolutionist. + + + + +VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +We have travelled rather far in our study of Greek science, and yet we +have not until now come to Greece itself. And even now, the men whose +names we are to consider were, for the most part, born in out-lying +portions of the empire; they differed from the others we have considered +only in the fact that they were drawn presently to the capital. The +change is due to a most interesting sequence of historical events. In +the day when Thales and his immediate successors taught in Miletus, when +the great men of the Italic school were in their prime, there was +no single undisputed Centre of Greek influence. The Greeks were a +disorganized company of petty nations, welded together chiefly by unity +of speech; but now, early in the fifth century B.C., occurred that +famous attack upon the Western world by the Persians under Darius and +his son and successor Xerxes. A few months of battling determined the +fate of the Western world. The Orientals were hurled back; the glorious +memories of Marathon, Salamis, and Plataea stimulated the patriotism and +enthusiasm of all children of the Greek race. The Greeks, for the +first time, occupied the centre of the historical stage; for the brief +interval of about half a century the different Grecian principalities +lived together in relative harmony. One city was recognized as the +metropolis of the loosely bound empire; one city became the home of +culture and the Mecca towards which all eyes turned; that city, of +course, was Athens. For a brief time all roads led to Athens, as, at a +later date, they all led to Rome. The waterways which alone bound the +widely scattered parts of Hellas into a united whole led out from Athens +and back to Athens, as the spokes of a wheel to its hub. Athens was the +commercial centre, and, largely for that reason, it became the centre of +culture and intellectual influence also. The wise men from the colonies +visited the metropolis, and the wise Athenians went out to the colonies. +Whoever aspired to become a leader in politics, in art, in literature, +or in philosophy, made his way to the capital, and so, with almost +bewildering suddenness, there blossomed the civilization of the age +of Pericles; the civilization which produced aeschylus, Sophocles, +Euripides, Herodotus, and Thucydides; the civilization which made +possible the building of the Parthenon. + + +ANAXAGORAS + +Sometime during the early part of this golden age there came to Athens a +middle-aged man from Clazomenae, who, from our present stand-point, +was a more interesting personality than perhaps any other in the great +galaxy of remarkable men assembled there. The name of this new-comer was +Anaxagoras. It was said in after-time, we know not with what degree of +truth, that he had been a pupil of Anaximenes. If so, he was a pupil who +departed far from the teachings of his master. What we know for certain +is that Anaxagoras was a truly original thinker, and that he became a +close friend--in a sense the teacher--of Pericles and of Euripides. Just +how long he remained at Athens is not certain; but the time came when +he had made himself in some way objectionable to the Athenian populace +through his teachings. Filled with the spirit of the investigator, +he could not accept the current conceptions as to the gods. He was a +sceptic, an innovator. Such men are never welcome; they are the chief +factors in the progress of thought, but they must look always to +posterity for recognition of their worth; from their contemporaries they +receive, not thanks, but persecution. Sometimes this persecution takes +one form, sometimes another; to the credit of the Greeks be it said, +that with them it usually led to nothing more severe than banishment. In +the case of Anaxagoras, it is alleged that the sentence pronounced was +death; but that, thanks to the influence of Pericles, this sentence was +commuted to banishment. In any event, the aged philosopher was sent away +from the city of his adoption. He retired to Lampsacus. "It is not I +that have lost the Athenians," he said; "it is the Athenians that have +lost me." + +The exact position which Anaxagoras had among his contemporaries, and +his exact place in the development of philosophy, have always been +somewhat in dispute. It is not known, of a certainty, that he even held +an open school at Athens. Ritter thinks it doubtful that he did. It was +his fate to be misunderstood, or underestimated, by Aristotle; that in +itself would have sufficed greatly to dim his fame--might, indeed, have +led to his almost entire neglect had he not been a truly remarkable +thinker. With most of the questions that have exercised the commentators +we have but scant concern. Following Aristotle, most historians of +philosophy have been metaphysicians; they have concerned themselves +far less with what the ancient thinkers really knew than with what they +thought. A chance using of a verbal quibble, an esoteric phrase, the +expression of a vague mysticism--these would suffice to call forth reams +of exposition. It has been the favorite pastime of historians to +weave their own anachronistic theories upon the scanty woof of the +half-remembered thoughts of the ancient philosophers. To make such cloth +of the imagination as this is an alluring pastime, but one that must not +divert us here. Our point of view reverses that of the philosophers. +We are chiefly concerned, not with some vague saying of Anaxagoras, but +with what he really knew regarding the phenomena of nature; with what +he observed, and with the comprehensible deductions that he derived +from his observations. In attempting to answer these inquiries, we are +obliged, in part, to take our evidence at second-hand; but, fortunately, +some fragments of writings of Anaxagoras have come down to us. We are +told that he wrote only a single book. It was said even (by Diogenes) +that he was the first man that ever wrote a work in prose. The latter +statement would not bear too close an examination, yet it is true that +no extensive prose compositions of an earlier day than this have +been preserved, though numerous others are known by their fragments. +Herodotus, "the father of prose," was a slightly younger contemporary of +the Clazomenaean philosopher; not unlikely the two men may have met at +Athens. + +Notwithstanding the loss of the greater part of the writings of +Anaxagoras, however, a tolerably precise account of his scientific +doctrines is accessible. Diogenes Laertius expresses some of them +in very clear and precise terms. We have already pointed out the +uncertainty that attaches to such evidence as this, but it is as valid +for Anaxagoras as for another. If we reject such evidence, we shall +often have almost nothing left; in accepting it we may at least feel +certain that we are viewing the thinker as his contemporaries and +immediate successors viewed him. Following Diogenes, then, we shall +find some remarkable scientific opinions ascribed to Anaxagoras. "He +asserted," we are told, "that the sun was a mass of burning iron, +greater than Peloponnesus, and that the moon contained houses and also +hills and ravines." In corroboration of this, Plato represents him as +having conjectured the right explanation of the moon's light, and of the +solar and lunar eclipses. He had other astronomical theories that were +more fanciful; thus "he said that the stars originally moved about +in irregular confusion, so that at first the pole-star, which is +continually visible, always appeared in the zenith, but that afterwards +it acquired a certain declination, and that the Milky Way was a +reflection of the light of the sun when the stars did not appear. The +comets he considered to be a concourse of planets emitting rays, and +the shooting-stars he thought were sparks, as it were, leaping from the +firmament." + +Much of this is far enough from the truth, as we now know it, yet all +of it shows an earnest endeavor to explain the observed phenomena of the +heavens on rational principles. To have predicated the sun as a great +molten mass of iron was indeed a wonderful anticipation of the results +of the modern spectroscope. Nor can it be said that this hypothesis of +Anaxagoras was a purely visionary guess. It was in all probability a +scientific deduction from the observed character of meteoric stones. +Reference has already been made to the alleged prediction of the fall +of the famous meteor at aegespotomi by Anaxagoras. The assertion that +he actually predicted this fall in any proper sense of the word would +be obviously absurd. Yet the fact that his name is associated with it +suggests that he had studied similar meteorites, or else that he studied +this particular one, since it is not quite clear whether it was before +or after this fall that he made the famous assertion that space is full +of falling stones. We should stretch the probabilities were we to assert +that Anaxagoras knew that shooting-stars and meteors were the same, +yet there is an interesting suggestiveness in his likening the +shooting-stars to sparks leaping from the firmament, taken in connection +with his observation on meteorites. Be this as it may, the fact that +something which falls from heaven as a blazing light turns out to be +an iron-like mass may very well have suggested to the most rational +of thinkers that the great blazing light called the sun has the same +composition. This idea grasped, it was a not unnatural extension to +conceive the other heavenly bodies as having the same composition. + +This led to a truly startling thought. Since the heavenly bodies are +of the same composition as the earth, and since they are observed to +be whirling about the earth in space, may we not suppose that they were +once a part of the earth itself, and that they have been thrown off by +the force of a whirling motion? Such was the conclusion which Anaxagoras +reached; such his explanation of the origin of the heavenly bodies. It +was a marvellous guess. Deduct from it all that recent science has shown +to be untrue; bear in mind that the stars are suns, compared with which +the earth is a mere speck of dust; recall that the sun is parent, not +daughter, of the earth, and despite all these deductions, the cosmogonic +guess of Anaxagoras remains, as it seems to us, one of the most +marvellous feats of human intelligence. It was the first explanation of +the cosmic bodies that could be called, in any sense, an anticipation of +what the science of our own day accepts as a true explanation of cosmic +origins. Moreover, let us urge again that this was no mere accidental +flight of the imagination; it was a scientific induction based on the +only data available; perhaps it is not too much to say that it was the +only scientific induction which these data would fairly sustain. Of +course it is not for a moment to be inferred that Anaxagoras understood, +in the modern sense, the character of that whirling force which we call +centrifugal. About two thousand years were yet to elapse before that +force was explained as elementary inertia; and even that explanation, +let us not forget, merely sufficed to push back the barriers of mystery +by one other stage; for even in our day inertia is a statement of fact +rather than an explanation. + +But however little Anaxagoras could explain the centrifugal force +on mechanical principles, the practical powers of that force were +sufficiently open to his observation. The mere experiment of throwing +a stone from a sling would, to an observing mind, be full of +suggestiveness. It would be obvious that by whirling the sling about, +the stone which it held would be sustained in its circling path about +the hand in seeming defiance of the earth's pull, and after the stone +had left the sling, it could fly away from the earth to a distance which +the most casual observation would prove to be proportionate to the speed +of its flight. Extremely rapid motion, then, might project bodies from +the earth's surface off into space; a sufficiently rapid whirl would +keep them there. Anaxagoras conceived that this was precisely what +had occurred. His imagination even carried him a step farther--to a +conception of a slackening of speed, through which the heavenly bodies +would lose their centrifugal force, and, responding to the perpetual +pull of gravitation, would fall back to the earth, just as the great +stone at aegespotomi had been observed to do. + +Here we would seem to have a clear conception of the idea of universal +gravitation, and Anaxagoras stands before us as the anticipator of +Newton. Were it not for one scientific maxim, we might exalt the old +Greek above the greatest of modern natural philosophers; but that maxim +bids us pause. It is phrased thus, "He discovers who proves." Anaxagoras +could not prove; his argument was at best suggestive, not demonstrative. +He did not even know the laws which govern falling bodies; much less +could he apply such laws, even had he known them, to sidereal bodies at +whose size and distance he could only guess in the vaguest terms. Still +his cosmogonic speculation remains as perhaps the most remarkable one of +antiquity. How widely his speculation found currency among his immediate +successors is instanced in a passage from Plato, where Socrates is +represented as scornfully answering a calumniator in these terms: "He +asserts that I say the sun is a stone and the moon an earth. Do you +think of accusing Anaxagoras, Miletas, and have you so low an opinion of +these men, and think them so unskilled in laws, as not to know that the +books of Anaxagoras the Clazomenaean are full of these doctrines. +And forsooth the young men are learning these matters from me which +sometimes they can buy from the orchestra for a drachma, at the most, +and laugh at Socrates if he pretends they are his-particularly seeing +they are so strange." + +The element of error contained in these cosmogonic speculations of +Anaxagoras has led critics to do them something less than justice. But +there is one other astronomical speculation for which the Clazomenaean +philosopher has received full credit. It is generally admitted that it +was he who first found out the explanation of the phases of the moon; +a knowledge that that body shines only by reflected light, and that its +visible forms, waxing and waning month by month from crescent to disk +and from disk to crescent, merely represent our shifting view of its +sun-illumined face. It is difficult to put ourselves in the place of +the ancient observer and realize how little the appearances suggest the +actual fact. That a body of the same structure as the earth should shine +with the radiance of the moon merely because sunlight is reflected +from it, is in itself a supposition seemingly contradicted by ordinary +experience. It required the mind of a philosopher, sustained, perhaps, +by some experimental observations, to conceive the idea that what seems +so obviously bright may be in reality dark. The germ of the conception +of what the philosopher speaks of as the noumena, or actualities, +back of phenomena or appearances, had perhaps this crude beginning. +Anaxagoras could surely point to the moon in support of his seeming +paradox that snow, being really composed of water, which is dark, is in +reality black and not white--a contention to which we shall refer more +at length in a moment. + +But there is yet another striking thought connected with this new +explanation of the phases of the moon. The explanation implies not +merely the reflection of light by a dark body, but by a dark body of a +particular form. Granted that reflections are in question, no body but +a spherical one could give an appearance which the moon presents. The +moon, then, is not merely a mass of earth, it is a spherical mass of +earth. Here there were no flaws in the reasoning of Anaxagoras. By +scientific induction he passed from observation to explanation. A new +and most important element was added to the science of astronomy. + +Looking back from the latter-day stand-point, it would seem as if the +mind of the philosopher must have taken one other step: the mind that +had conceived sun, moon, stars, and earth to be of one substance might +naturally, we should think, have reached out to the further induction +that, since the moon is a sphere, the other cosmic bodies, including the +earth, must be spheres also. But generalizer as he was, Anaxagoras was +too rigidly scientific a thinker to make this assumption. The data +at his command did not, as he analyzed them, seem to point to this +conclusion. We have seen that Pythagoras probably, and Parmenides +surely, out there in Italy had conceived the idea of the earth's +rotundity, but the Pythagorean doctrines were not rapidly taken up in +the mother-country, and Parmenides, it must be recalled, was a strict +contemporary of Anaxagoras himself. It is no reproach, therefore, to the +Clazomenaean philosopher that he should have held to the old idea +that the earth is flat, or at most a convex disk--the latter being the +Babylonian conception which probably dominated that Milesian school to +which Anaxagoras harked back. + +Anaxagoras may never have seen an eclipse of the moon, and even if he +had he might have reflected that, from certain directions, a disk may +throw precisely the same shadow as a sphere. Moreover, in reference +to the shadow cast by the earth, there was, so Anaxagoras believed, +an observation open to him nightly which, we may well suppose, was not +without influence in suggesting to his mind the probable shape of the +earth. The Milky Way, which doubtless had puzzled astronomers from the +beginnings of history and which was to continue to puzzle them for many +centuries after the day of Anaxagoras, was explained by the Clazomenaean +philosopher on a theory obviously suggested by the theory of the moon's +phases. Since the earth-like moon shines by reflected light at night, +and since the stars seem obviously brighter on dark nights, Anaxagoras +was but following up a perfectly logical induction when he propounded +the theory that the stars in the Milky Way seem more numerous and +brighter than those of any other part of the heavens, merely because +the Milky Way marks the shadow of the earth. Of course the inference was +wrong, so far as the shadow of the earth is concerned; yet it contained +a part truth, the force of which was never fully recognized until the +time of Galileo. This consists in the assertion that the brightness of +the Milky Way is merely due to the glow of many stars. The shadow-theory +of Anaxagoras would naturally cease to have validity so soon as the +sphericity of the earth was proved, and with it, seemingly, fell for the +time the companion theory that the Milky Way is made up of a multitude +of stars. + +It has been said by a modern critic(1) that the shadow-theory was +childish in that it failed to note that the Milky Way does not follow +the course of the ecliptic. But this criticism only holds good so long +as we reflect on the true character of the earth as a symmetrical body +poised in space. It is quite possible to conceive a body occupying +the position of the earth with reference to the sun which would cast a +shadow having such a tenuous form as the Milky Way presents. Such a body +obviously would not be a globe, but a long-drawn-out, attenuated +figure. There is, to be sure, no direct evidence preserved to show that +Anaxagoras conceived the world to present such a figure as this, but +what we know of that philosopher's close-reasoning, logical mind gives +some warrant to the assumption--gratuitous though in a sense it be--that +the author of the theory of the moon's phases had not failed to ask +himself what must be the form of that terrestrial body which could cast +the tenuous shadow of the Milky Way. Moreover, we must recall that the +habitable earth, as known to the Greeks of that day, was a relatively +narrow band of territory, stretching far to the east and to the west. + + +Anaxagoras as Meteorologist + +The man who had studied the meteorite of aegospotami, and been put by +it on the track of such remarkable inductions, was, naturally, not +oblivious to the other phenomena of the atmosphere. Indeed, such a mind +as that of Anaxagoras was sure to investigate all manner of natural +phenomena, and almost equally sure to throw new light on any subject +that it investigated. Hence it is not surprising to find Anaxagoras +credited with explaining the winds as due to the rarefactions of the +atmosphere produced by the sun. This explanation gives Anaxagoras full +right to be called "the father of meteorology," a title which, it may +be, no one has thought of applying to him, chiefly because the science +of meteorology did not make its real beginnings until some twenty-four +hundred years after the death of its first great votary. Not content +with explaining the winds, this prototype of Franklin turned his +attention even to the tipper atmosphere. "Thunder," he is reputed to +have said, "was produced by the collision of the clouds, and lightning +by the rubbing together of the clouds." We dare not go so far as to +suggest that this implies an association in the mind of Anaxagoras +between the friction of the clouds and the observed electrical effects +generated by the friction of such a substance as amber. To make such +a suggestion doubtless would be to fall victim to the old familiar +propensity to read into Homer things that Homer never knew. Yet the +significant fact remains that Anaxagoras ascribed to thunder and to +lightning their true position as strictly natural phenomena. For him it +was no god that menaced humanity with thundering voice and the flash of +his divine fires from the clouds. Little wonder that the thinker whose +science carried him to such scepticism as this should have felt the +wrath of the superstitious Athenians. + + +Biological Speculations + +Passing from the phenomena of the air to those of the earth itself, we +learn that Anaxagoras explained an earthquake as being produced by +the returning of air into the earth. We cannot be sure as to the exact +meaning here, though the idea that gases are imprisoned in the substance +of the earth seems not far afield. But a far more remarkable insight +than this would imply was shown by Anaxagoras when he asserted that a +certain amount of air is contained in water, and that fishes breathe +this air. The passage of Aristotle in which this opinion is ascribed to +Anaxagoras is of sufficient interest to be quoted at length: + +"Democritus, of Abdera," says Aristotle, "and some others, that have +spoken concerning respiration, have determined nothing concerning +other animals, but seem to have supposed that all animals respire. +But Anaxagoras and Diogenes (Apolloniates), who say that all animals +respire, have also endeavored to explain how fishes, and all those +animals that have a hard, rough shell, such as oysters, mussels, etc., +respire. And Anaxagoras, indeed, says that fishes, when they emit water +through their gills, attract air from the mouth to the vacuum in the +viscera from the water which surrounds the mouth; as if air was inherent +in the water."(2) + +It should be recalled that of the three philosophers thus mentioned +as contending that all animals respire, Anaxagoras was the elder; +he, therefore, was presumably the originator of the idea. It will be +observed, too, that Anaxagoras alone is held responsible for the idea +that fishes respire air through their gills, "attracting" it from the +water. This certainly was one of the shrewdest physiological guesses +of any age, if it be regarded as a mere guess. With greater justice +we might refer to it as a profound deduction from the principle of the +uniformity of nature. + +In making such a deduction, Anaxagoras was far in advance of his time as +illustrated by the fact that Aristotle makes the citation we have just +quoted merely to add that "such things are impossible," and to refute +these "impossible" ideas by means of metaphysical reasonings that seemed +demonstrative not merely to himself, but to many generations of his +followers. + +We are told that Anaxagoras alleged that all animals were originally +generated out of moisture, heat, and earth particles. Just what opinion +he held concerning man's development we are not informed. Yet there is +one of his phrases which suggests--without, perhaps, quite proving--that +he was an evolutionist. This phrase asserts, with insight that is fairly +startling, that man is the most intelligent of animals because he has +hands. The man who could make that assertion must, it would seem, have +had in mind the idea of the development of intelligence through the use +of hands--an idea the full force of which was not evident to subsequent +generations of thinkers until the time of Darwin. + + +Physical Speculations + +Anaxagoras is cited by Aristotle as believing that "plants are animals +and feel pleasure and pain, inferring this because they shed their +leaves and let them grow again." The idea is fanciful, yet it suggests +again a truly philosophical conception of the unity of nature. The man +who could conceive that idea was but little hampered by traditional +conceptions. He was exercising a rare combination of the rigidly +scientific spirit with the poetical imagination. He who possesses these +gifts is sure not to stop in his questionings of nature until he has +found some thinkable explanation of the character of matter itself. +Anaxagoras found such an explanation, and, as good luck would have it, +that explanation has been preserved. Let us examine his reasoning in +some detail. We have already referred to the claim alleged to have +been made by Anaxagoras that snow is not really white, but black. The +philosopher explained his paradox, we are told, by asserting that +snow is really water, and that water is dark, when viewed under proper +conditions--as at the bottom of a well. That idea contains the germ +of the Clazomenaean philosopher's conception of the nature of matter. +Indeed, it is not unlikely that this theory of matter grew out of his +observation of the changing forms of water. He seems clearly to have +grasped the idea that snow on the one hand, and vapor on the other, are +of the same intimate substance as the water from which they are derived +and into which they may be again transformed. The fact that steam and +snow can be changed back into water, and by simple manipulation cannot +be changed into any other substance, finds, as we now believe, its +true explanation in the fact that the molecular structure, as we phrase +it--that is to say, the ultimate particle of which water is composed, is +not changed, and this is precisely the explanation which Anaxagoras gave +of the same phenomena. For him the unit particle of water constituted an +elementary body, uncreated, unchangeable, indestructible. This particle, +in association with like particles, constitutes the substance which +we call water. The same particle in association with particles unlike +itself, might produce totally different substances--as, for example, +when water is taken up by the roots of a plant and becomes, seemingly, +a part of the substance of the plant. But whatever the changed +association, so Anaxagoras reasoned, the ultimate particle of water +remains a particle of water still. And what was true of water was true +also, so he conceived, of every other substance. Gold, silver, iron, +earth, and the various vegetables and animal tissues--in short, each and +every one of all the different substances with which experience makes us +familiar, is made up of unit particles which maintain their integrity in +whatever combination they may be associated. This implies, obviously, a +multitude of primordial particles, each one having an individuality of +its own; each one, like the particle of water already cited, uncreated, +unchangeable, and indestructible. + +Fortunately, we have the philosopher's own words to guide us as to his +speculations here. The fragments of his writings that have come down +to us (chiefly through the quotations of Simplicius) deal almost +exclusively with these ultimate conceptions of his imagination. +In ascribing to him, then, this conception of diverse, uncreated, +primordial elements, which can never be changed, but can only be mixed +together to form substances of the material world, we are not reading +back post-Daltonian knowledge into the system of Anaxagoras. Here are +his words: "The Greeks do not rightly use the terms 'coming into being' +and 'perishing.' For nothing comes into being, nor, yet, does anything +perish; but there is mixture and separation of things that are. So they +would do right in calling 'coming into being' 'mixture' and 'perishing' +'separation.' For how could hair come from what is not hair? Or flesh +from what is not flesh?" + +Elsewhere he tells us that (at one stage of the world's development) +"the dense, the moist, the cold, the dark, collected there where now +is earth; the rare, the warm, the dry, the bright, departed towards the +further part of the aether. The earth is condensed out of these things +that are separated, for water is separated from the clouds, and earth +from the water; and from the earth stones are condensed by the cold, and +these are separated farther from the water." Here again the influence of +heat and cold in determining physical qualities is kept pre-eminently in +mind. The dense, the moist, the cold, the dark are contrasted with the +rare, the warm, the dry, and bright; and the formation of stones is +spoken of as a specific condensation due to the influence of cold. Here, +then, we have nearly all the elements of the Daltonian theory of atoms +on the one hand, and the nebular hypothesis of Laplace on the other. But +this is not quite all. In addition to such diverse elementary particles +as those of gold, water, and the rest, Anaxagoras conceived a species of +particles differing from all the others, not merely as they differ +from one another, but constituting a class by themselves; particles +infinitely smaller than the others; particles that are described as +infinite, self-powerful, mixed with nothing, but existing alone. That is +to say (interpreting the theory in the only way that seems plausible), +these most minute particles do not mix with the other primordial +particles to form material substances in the same way in which these +mixed with one another. But, on the other hand, these "infinite, +self-powerful, and unmixed" particles commingle everywhere and in every +substance whatever with the mixed particles that go to make up the +substances. + +There is a distinction here, it will be observed, which at once +suggests the modern distinction between physical processes and chemical +processes, or, putting it otherwise, between molecular processes and +atomic processes; but the reader must be guarded against supposing that +Anaxagoras had any such thought as this in mind. His ultimate mixable +particles can be compared only with the Daltonian atom, not with the +molecule of the modern physicist, and his "infinite, self-powerful, and +unmixable" particles are not comparable with anything but the ether of +the modern physicist, with which hypothetical substance they have many +points of resemblance. But the "infinite, self-powerful, and unmixed" +particles constituting thus an ether-like plenum which permeates all +material structures, have also, in the mind of Anaxagoras, a function +which carries them perhaps a stage beyond the province of the modern +ether. For these "infinite, self powerful, and unmixed" particles are +imbued with, and, indeed, themselves constitute, what Anaxagoras terms +nous, a word which the modern translator has usually paraphrased as +"mind." Neither that word nor any other available one probably conveys +an accurate idea of what Anaxagoras meant to imply by the word nous. +For him the word meant not merely "mind" in the sense of receptive and +comprehending intelligence, but directive and creative intelligence as +well. Again let Anaxagoras speak for himself: "Other things include +a portion of everything, but nous is infinite, and self-powerful, and +mixed with nothing, but it exists alone, itself by itself. For if it +were not by itself, but were mixed with anything else, it would include +parts of all things, if it were mixed with anything; for a portion of +everything exists in every thing, as has been said by me before, and +things mingled with it would prevent it from having power over anything +in the same way that it does now that it is alone by itself. For it is +the most rarefied of all things and the purest, and it has all knowledge +in regard to everything and the greatest power; over all that has life, +both greater and less, nous rules. And nous ruled the rotation of the +whole, so that it set it in rotation in the beginning. First it began +the rotation from a small beginning, then more and more was included +in the motion, and yet more will be included. Both the mixed and the +separated and distinct, all things nous recognized. And whatever things +were to be, and whatever things were, as many as are now, and whatever +things shall be, all these nous arranged in order; and it arranged that +rotation, according to which now rotate stars and sun and moon and air +and aether, now that they are separated. Rotation itself caused the +separation, and the dense is separated from the rare, the warm from the +cold, the bright from the dark, the dry from the moist. And when nous +began to set things in motion, there was separation from everything that +was in motion, all this was made distinct. The rotation of the +things that were moved and made distinct caused them to be yet more +distinct."(3) + +Nous, then, as Anaxagoras conceives it, is "the most rarefied of all +things, and the purest, and it has knowledge in regard to everything and +the greatest power; over all that has life, both greater and less, it +rules." But these are postulants of omnipresence and omniscience. In +other words, nous is nothing less than the omnipotent artificer of the +material universe. It lacks nothing of the power of deity, save only +that we are not assured that it created the primordial particles. The +creation of these particles was a conception that for Anaxagoras, as +for the modern Spencer, lay beyond the range of imagination. Nous is +the artificer, working with "uncreated" particles. Back of nous and the +particles lies, for an Anaxagoras as for a Spencer, the Unknowable. But +nous itself is the equivalent of that universal energy of motion which +science recognizes as operating between the particles of matter, and +which the theologist personifies as Deity. It is Pantheistic deity +as Anaxagoras conceives it; his may be called the first scientific +conception of a non-anthropomorphic god. In elaborating this conception +Anaxagoras proved himself one of the most remarkable scientific +dreamers of antiquity. To have substituted for the Greek Pantheon +of anthropomorphic deities the conception of a non-anthropomorphic +immaterial and ethereal entity, of all things in the world "the most +rarefied and the purest," is to have performed a feat which, considering +the age and the environment in which it was accomplished, staggers the +imagination. As a strictly scientific accomplishment the great thinker's +conception of primordial elements contained a germ of the truth which +was to lie dormant for 2200 years, but which then, as modified and +vitalized by the genius of Dalton, was to dominate the new chemical +science of the nineteenth century. If there are intimations that the +primordial element of Anaxagoras and of Dalton may turn out in the near +future to be itself a compound, there will still remain the yet finer +particles of the nous of Anaxagoras to baffle the most subtle analysis +of which to-day's science gives us any pre-vision. All in all, then, +the work of Anaxagoras must stand as that of perhaps the most far-seeing +scientific imagination of pre-Socratic antiquity. + + +LEUCIPPUS AND DEMOCRITUS + +But we must not leave this alluring field of speculation as to the +nature of matter without referring to another scientific guess, which +soon followed that of Anaxagoras and was destined to gain even wider +fame, and which in modern times has been somewhat unjustly held to +eclipse the glory of the other achievement. We mean, of course, the +atomic theory of Leucippus and Democritus. This theory reduced all +matter to primordial elements, called atoms (gr atoma) because they are +by hypothesis incapable of further division. These atoms, making up the +entire material universe, are in this theory conceived as qualitatively +identical, differing from one another only in size and perhaps in shape. +The union of different-sized atoms in endless combinations produces the +diverse substances with which our senses make us familiar. + +Before we pass to a consideration of this alluring theory, and +particularly to a comparison of it with the theory of Anaxagoras, we +must catch a glimpse of the personality of the men to whom the theory +owes its origin. One of these, Leucippus, presents so uncertain a figure +as to be almost mythical. Indeed, it was long questioned whether such +a man had actually lived, or whether he were not really an invention +of his alleged disciple, Democritus. Latterday scholarship, however, +accepts him as a real personage, though knowing scarcely more of him +than that he was the author of the famous theory with which his name +was associated. It is suggested that he was a wanderer, like most +philosophers of his time, and that later in life he came to Abdera, in +Thrace, and through this circumstance became the teacher of Democritus. +This fable answers as well as another. What we really know is that +Democritus himself, through whose writings and teachings the atomic +theory gained vogue, was born in Abdera, about the year 460 B.C.--that +is to say, just about the time when his great precursor, Anaxagoras, +was migrating to Athens. Democritus, like most others of the early Greek +thinkers, lives in tradition as a picturesque figure. It is vaguely +reported that he travelled for a time, perhaps in the East and in Egypt, +and that then he settled down to spend the remainder of his life in +Abdera. Whether or not he visited Athens in the course of his wanderings +we do not know. At Abdera he was revered as a sage, but his influence +upon the practical civilization of the time was not marked. He was +pre-eminently a dreamer and a writer. Like his confreres of the +epoch, he entered all fields of thought. He wrote voluminously, but, +unfortunately, his writings have, for the most part, perished. The +fables and traditions of a later day asserted that Democritus had +voluntarily put out his own eyes that he might turn his thoughts inward +with more concentration. Doubtless this is fiction, yet, as usual with +such fictions, it contains a germ of truth; for we may well suppose that +the promulgator of the atomic theory was a man whose mind was attracted +by the subtleties of thought rather than by the tangibilities of +observation. Yet the term "laughing philosopher," which seems to have +been universally applied to Democritus, suggests a mind not altogether +withdrawn from the world of practicalities. + +So much for Democritus the man. Let us return now to his theory of +atoms. This theory, it must be confessed, made no very great impression +upon his contemporaries. It found an expositor, a little later, in the +philosopher Epicurus, and later still the poet Lucretius gave it popular +expression. But it seemed scarcely more than the dream of a philosopher +or the vagary of a poet until the day when modern science began to +penetrate the mysteries of matter. When, finally, the researches of +Dalton and his followers had placed the atomic theory on a surer footing +as the foundation of modern chemistry, the ideas of the old laughing +philosopher of Abdera, which all along had been half derisively +remembered, were recalled with a new interest. Now it appeared that +these ideas had curiously foreshadowed nineteenth-century knowledge. It +appeared that away back in the fifth century B.C. a man had dreamed out +a conception of the ultimate nature of matter which had waited all these +centuries for corroboration. And now the historians of philosophy became +more than anxious to do justice to the memory of Democritus. + +It is possible that this effort at poetical restitution has carried the +enthusiast too far. There is, indeed, a curious suggestiveness in the +theory of Democritus; there is philosophical allurement in his reduction +of all matter to a single element; it contains, it may be, not merely a +germ of the science of the nineteenth-century chemistry, but perhaps the +germs also of the yet undeveloped chemistry of the twentieth century. +Yet we dare suggest that in their enthusiasm for the atomic theory of +Democritus the historians of our generation have done something less +than justice to that philosopher's precursor, Anaxagoras. And one +suspects that the mere accident of a name has been instrumental in +producing this result. Democritus called his primordial element an atom; +Anaxagoras, too, conceived a primordial element, but he called it merely +a seed or thing; he failed to christen it distinctively. Modern science +adopted the word atom and gave it universal vogue. It owed a debt of +gratitude to Democritus for supplying it the word, but it somewhat +overpaid the debt in too closely linking the new meaning of the word +with its old original one. For, let it be clearly understood, the +Daltonian atom is not precisely comparable with the atom of Democritus. +The atom, as Democritus conceived it, was monistic; all atoms, according +to this hypothesis, are of the same substance; one atom differs from +another merely in size and shape, but not at all in quality. But the +Daltonian hypothesis conceived, and nearly all the experimental efforts +of the nineteenth century seemed to prove, that there are numerous +classes of atoms, each differing in its very essence from the others. + +As the case stands to-day the chemist deals with seventy-odd substances, +which he calls elements. Each one of these substances is, as he +conceives it, made up of elementary atoms having a unique personality, +each differing in quality from all the others. As far as experiment has +thus far safely carried us, the atom of gold is a primordial element +which remains an atom of gold and nothing else, no matter with what +other atoms it is associated. So, too, of the atom of silver, or zinc, +or sodium--in short, of each and every one of the seventy-odd elements. +There are, indeed, as we shall see, experiments that suggest the +dissolution of the atom--that suggest, in short, that the Daltonian atom +is misnamed, being a structure that may, under certain conditions, be +broken asunder. But these experiments have, as yet, the warrant rather +of philosophy than of pure science, and to-day we demand that the +philosophy of science shall be the handmaid of experiment. + +When experiment shall have demonstrated that the Daltonian atom is a +compound, and that in truth there is but a single true atom, which, +combining with its fellows perhaps in varying numbers and in different +special relations, produces the Daltonian atoms, then the philosophical +theory of monism will have the experimental warrant which to-day it +lacks; then we shall be a step nearer to the atom of Democritus in one +direction, a step farther away in the other. We shall be nearer, in that +the conception of Democritus was, in a sense, monistic; farther away, in +that all the atoms of Democritus, large and small alike, were considered +as permanently fixed in size. Democritus postulated all his atoms as of +the same substance, differing not at all in quality; yet he was obliged +to conceive that the varying size of the atoms gave to them varying +functions which amounted to qualitative differences. He might claim for +his largest atom the same quality of substance as for his smallest, but +so long as he conceived that the large atoms, when adjusted together to +form a tangible substance, formed a substance different in quality +from the substance which the small atoms would make up when similarly +grouped, this concession amounts to the predication of difference of +quality between the atoms themselves. The entire question reduces +itself virtually to a quibble over the word quality, So long as one atom +conceived to be primordial and indivisible is conceded to be of such a +nature as necessarily to produce a different impression on our senses, +when grouped with its fellows, from the impression produced by other +atoms when similarly grouped, such primordial atoms do differ among +themselves in precisely the same way for all practical purposes as do +the primordial elements of Anaxagoras. + +The monistic conception towards which twentieth-century chemistry seems +to be carrying us may perhaps show that all the so-called atoms are +compounded of a single element. All the true atoms making up that +element may then properly be said to have the same quality, but none the +less will it remain true that the combinations of that element that +go to make up the different Daltonian atoms differ from one another in +quality in precisely the same sense in which such tangible substances as +gold, and oxygen, and mercury, and diamonds differ from one another. In +the last analysis of the monistic philosophy, there is but one substance +and one quality in the universe. In the widest view of that philosophy, +gold and oxygen and mercury and diamonds are one substance, and, if you +please, one quality. But such refinements of analysis as this are for +the transcendental philosopher, and not for the scientist. Whatever the +allurement of such reasoning, we must for the purpose of science let +words have a specific meaning, nor must we let a mere word-jugglery +blind us to the evidence of facts. That was the rock on which Greek +science foundered; it is the rock which the modern helmsman sometimes +finds it difficult to avoid. And if we mistake not, this case of the +atom of Democritus is precisely a case in point. Because Democritus said +that his atoms did not differ in quality, the modern philosopher has +seen in his theory the essentials of monism; has discovered in it not +merely a forecast of the chemistry of the nineteenth century, but a +forecast of the hypothetical chemistry of the future. And, on the +other hand, because Anaxagoras predicted a different quality for his +primordial elements, the philosopher of our day has discredited the +primordial element of Anaxagoras. + +Yet if our analysis does not lead us astray, the theory of Democritus +was not truly monistic; his indestructible atoms, differing from one +another in size and shape, utterly incapable of being changed from the +form which they had maintained from the beginning, were in reality +as truly and primordially different as are the primordial elements of +Anaxagoras. In other words, the atom of Democritus is nothing less than +the primordial seed of Anaxagoras, a little more tangibly visualized and +given a distinctive name. Anaxagoras explicitly conceived his elements +as invisibly small, as infinite in number, and as made up of an +indefinite number of kinds--one for each distinctive substance in +the world. But precisely the same postulates are made of the atom of +Democritus. These also are invisibly small; these also are infinite +in number; these also are made up of an indefinite number of kinds, +corresponding with the observed difference of substances in the world. +"Primitive seeds," or "atoms," were alike conceived to be primordial, +un-changeable, and indestructible. Wherein then lies the difference? We +answer, chiefly in a name; almost solely in the fact that Anaxagoras did +not attempt to postulate the physical properties of the elements beyond +stating that each has a distinctive personality, while Democritus did +attempt to postulate these properties. He, too, admitted that each +kind of element has its distinctive personality, and he attempted to +visualize and describe the characteristics of the personality. + +Thus while Anaxagoras tells us nothing of his elements except that they +differ from one another, Democritus postulates a difference in size, +imagines some elements as heavier and some as lighter, and conceives +even that the elements may be provided with projecting hooks, with the +aid of which they link themselves one with another. No one to-day takes +these crude visualizings seriously as to their details. The sole element +of truth which these dreamings contain, as distinguishing them from the +dreamings of Anaxagoras, is in the conception that the various atoms +differ in size and weight. Here, indeed, is a vague fore-shadowing of +that chemistry of form which began to come into prominence towards the +close of the nineteenth century. To have forecast even dimly this newest +phase of chemical knowledge, across the abyss of centuries, is indeed a +feat to put Democritus in the front rank of thinkers. But this estimate +should not blind us to the fact that the pre-vision of Democritus was +but a slight elaboration of a theory which had its origin with another +thinker. The association between Anaxagoras and Democritus cannot be +directly traced, but it is an association which the historian of ideas +should never for a moment forget. If we are not to be misled by mere +word-jugglery, we shall recognize the founder of the atomic theory of +matter in Anaxagoras; its expositors along slightly different lines in +Leucippus and Democritus; its re-discoverer of the nineteenth century +in Dalton. All in all, then, just as Anaxagoras preceded Democritus in +time, so must he take precedence over him also as an inductive thinker, +who carried the use of the scientific imagination to its farthest reach. + +An analysis of the theories of the two men leads to somewhat the same +conclusion that might be reached from a comparison of their lives. +Anaxagoras was a sceptical, experimental scientist, gifted also with +the prophetic imagination. He reasoned always from the particular to the +general, after the manner of true induction, and he scarcely took a step +beyond the confines of secure induction. True scientist that he was, +he could content himself with postulating different qualities for +his elements, without pretending to know how these qualities could be +defined. His elements were by hypothesis invisible, hence he would not +attempt to visualize them. Democritus, on the other hand, refused +to recognize this barrier. Where he could not know, he still did not +hesitate to guess. Just as he conceived his atom of a definite form with +a definite structure, even so he conceived that the atmosphere about him +was full of invisible spirits; he accepted the current superstitions of +his time. Like the average Greeks of his day, he even believed in such +omens as those furnished by inspecting the entrails of a fowl. These +chance bits of biography are weather-vanes of the mind of Democritus. +They tend to substantiate our conviction that Democritus must rank +below Anaxagoras as a devotee of pure science. But, after all, such +comparisons and estimates as this are utterly futile. The essential fact +for us is that here, in the fifth century before our era, we find put +forward the most penetrating guess as to the constitution of matter that +the history of ancient thought has to present to us. In one direction, +the avenue of progress is barred; there will be no farther step that way +till we come down the centuries to the time of Dalton. + + +HIPPOCRATES AND GREEK MEDICINE + +These studies of the constitution of matter have carried us to the +limits of the field of scientific imagination in antiquity; let us now +turn sharply and consider a department of science in which theory joins +hands with practicality. Let us witness the beginnings of scientific +therapeutics. + +Medicine among the early Greeks, before the time of Hippocrates, was +a crude mixture of religion, necromancy, and mysticism. Temples were +erected to the god of medicine, aesculapius, and sick persons made their +way, or were carried, to these temples, where they sought to gain the +favor of the god by suitable offerings, and learn the way to regain +their health through remedies or methods revealed to them in dreams by +the god. When the patient had been thus cured, he placed a tablet in the +temple describing his sickness, and telling by what method the god had +cured him. He again made suitable offerings at the temple, which were +sometimes in the form of gold or silver representations of the diseased +organ--a gold or silver model of a heart, hand, foot, etc. + +Nevertheless, despite this belief in the supernatural, many drugs +and healing lotions were employed, and the Greek physicians possessed +considerable skill in dressing wounds and bandaging. But they did not +depend upon these surgical dressings alone, using with them certain +appropriate prayers and incantations, recited over the injured member at +the time of applying the dressings. + +Even the very early Greeks had learned something of anatomy. The daily +contact with wounds and broken bones must of necessity lead to a crude +understanding of anatomy in general. The first Greek anatomist, however, +who is recognized as such, is said to have been Alcmaeon. He is said +to have made extensive dissections of the lower animals, and to have +described many hitherto unknown structures, such as the optic nerve and +the Eustachian canal--the small tube leading into the throat from the +ear. He is credited with many unique explanations of natural phenomena, +such as, for example, the explanation that "hearing is produced by the +hollow bone behind the ear; for all hollow things are sonorous." He was +a rationalist, and he taught that the brain is the organ of mind. The +sources of our information about his work, however, are unreliable. + +Democedes, who lived in the sixth century B.C., is the first physician +of whom we have any trustworthy history. We learn from Herodotus that he +came from Croton to aegina, where, in recognition of his skill, he was +appointed medical officer of the city. From aegina he was called to +Athens at an increased salary, and later was in charge of medical +affairs in several other Greek cities. He was finally called to Samos by +the tyrant Polycrates, who reigned there from about 536 to 522 B.C. But +on the death of Polycrates, who was murdered by the Persians, Democedes +became a slave. His fame as a physician, however, had reached the ears +of the Persian monarch, and shortly after his capture he was permitted +to show his skill upon King Darius himself. The Persian monarch was +suffering from a sprained ankle, which his Egyptian surgeons had been +unable to cure. Democedes not only cured the injured member but used +his influence in saving the lives of his Egyptian rivals, who had been +condemned to death by the king. + +At another time he showed his skill by curing the queen, who was +suffering from a chronic abscess of long standing. This so pleased the +monarch that he offered him as a reward anything he might desire, except +his liberty. But the costly gifts of Darius did not satisfy him so long +as he remained a slave; and determined to secure his freedom at any +cost, he volunteered to lead some Persian spies into his native country, +promising to use his influence in converting some of the leading men +of his nation to the Persian cause. Laden with the wealth that had +been heaped upon him by Darius, he set forth upon his mission, but upon +reaching his native city of Croton he threw off his mask, renounced his +Persian mission, and became once more a free Greek. + +While the story of Democedes throws little light upon the medical +practices of the time, it shows that paid city medical officers existed +in Greece as early as the fifth and sixth centuries B.C. Even then +there were different "schools" of medicine, whose disciples disagreed +radically in their methods of treating diseases; and there were also +specialists in certain diseases, quacks, and charlatans. Some physicians +depended entirely upon external lotions for healing all disorders; +others were "hydrotherapeutists" or "bath-physicians"; while there +were a host of physicians who administered a great variety of herbs and +drugs. There were also magicians who pretended to heal by sorcery, and +great numbers of bone-setters, oculists, and dentists. + +Many of the wealthy physicians had hospitals, or clinics, where patients +were operated upon and treated. They were not hospitals in our modern +understanding of the term, but were more like dispensaries, where +patients were treated temporarily, but were not allowed to remain for +any length of time. Certain communities established and supported these +dispensaries for the care of the poor. + +But anything approaching a rational system of medicine was not +established, until Hippocrates of Cos, the "father of medicine," came +upon the scene. In an age that produced Phidias, Lysias, Herodotus, +Sophocles, and Pericles, it seems but natural that the medical art +should find an exponent who would rise above superstitious dogmas +and lay the foundation for a medical science. His rejection of the +supernatural alone stamps the greatness of his genius. But, besides +this, he introduced more detailed observation of diseases, and +demonstrated the importance that attaches to prognosis. + +Hippocrates was born at Cos, about 460 B.C., but spent most of his life +at Larissa, in Thessaly. He was educated as a physician by his father, +and travelled extensively as an itinerant practitioner for several +years. His travels in different climates and among many different people +undoubtedly tended to sharpen his keen sense of observation. He was +a practical physician as well as a theorist, and, withal, a clear +and concise writer. "Life is short," he says, "opportunity fleeting, +judgment difficult, treatment easy, but treatment after thought is +proper and profitable." + +His knowledge of anatomy was necessarily very imperfect, and was gained +largely from his predecessors, to whom he gave full credit. Dissections +of the human body were forbidden him, and he was obliged to confine +his experimental researches to operations on the lower animals. His +knowledge of the structure and arrangement of the bones, however, was +fairly accurate, but the anatomy of the softer tissues, as he conceived +it, was a queer jumbling together of blood-vessels, muscles, and +tendons. He does refer to "nerves," to be sure, but apparently the +structures referred to are the tendons and ligaments, rather than the +nerves themselves. He was better acquainted with the principal organs +in the cavities of the body, and knew, for example, that the heart is +divided into four cavities, two of which he supposed to contain blood, +and the other two air. + +His most revolutionary step was his divorcing of the supernatural from +the natural, and establishing the fact that disease is due to natural +causes and should be treated accordingly. The effect of such an attitude +can hardly be over-estimated. The establishment of such a theory was +naturally followed by a close observation as to the course of diseases +and the effects of treatment. To facilitate this, he introduced the +custom of writing down his observations as he made them--the "clinical +history" of the case. Such clinical records are in use all over the +world to-day, and their importance is so obvious that it is almost +incomprehensible that they should have fallen into disuse shortly after +the time of Hippocrates, and not brought into general use again until +almost two thousand years later. + +But scarcely less important than his recognition of disease as a natural +phenomenon was the importance he attributed to prognosis. Prognosis, in +the sense of prophecy, was common before the time of Hippocrates. +But prognosis, as he practised it and as we understand it to-day, +is prophecy based on careful observation of the course of +diseases--something more than superstitious conjecture. + +Although Hippocratic medicine rested on the belief in natural causes, +nevertheless, dogma and theory held an important place. The humoral +theory of disease was an all-important one, and so fully was this +theory accepted that it influenced the science of medicine all through +succeeding centuries. According to this celebrated theory there are four +humors in the body--blood, phlegm, yellow bile, and black bile. When +these humors are mixed in exact proportions they constitute health; +but any deviations from these proportions produce disease. In treating +diseases the aim of the physician was to discover which of these humors +were out of proportion and to restore them to their natural equilibrium. +It was in the methods employed in this restitution, rather than a +disagreement about the humors themselves, that resulted in the various +"schools" of medicine. + +In many ways the surgery of Hippocrates showed a better understanding +of the structure of the organs than of their functions. Some of the +surgical procedures as described by him are followed, with slight +modifications, to-day. Many of his methods were entirely lost sight of +until modern times, and one, the treatment of dislocation of the +outer end of the collar-bone, was not revived until some time in the +eighteenth century. + +Hippocrates, it seems, like modern physicians, sometimes suffered +from the ingratitude of his patients. "The physician visits a patient +suffering from fever or a wound, and prescribes for him," he says; "on +the next day, if the patient feels worse the blame is laid upon the +physician; if, on the other hand, he feels better, nature is extolled, +and the physician reaps no praise." The essence of this has been +repeated in rhyme and prose by writers in every age and country, but +the "father of medicine" cautions physicians against allowing it to +influence their attitude towards their profession. + + + + +VIII. POST-SOCRATIC SCIENCE AT ATHENS--PLATO, ARISTOTLE, AND +THEOPHRASTUS + +Doubtless it has been noticed that our earlier scientists were as far +removed as possible from the limitations of specialism. In point of +fact, in this early day, knowledge had not been classified as it came +to be later on. The philosopher was, as his name implied, a lover of +knowledge, and he did not find it beyond the reach of his capacity to +apply himself to all departments of the field of human investigation. It +is nothing strange to discover that Anaximander and the Pythagoreans +and Anaxagoras have propounded theories regarding the structure of the +cosmos, the origin and development of animals and man, and the nature of +matter itself. Nowadays, so enormously involved has become the mass of +mere facts regarding each of these departments of knowledge that no one +man has the temerity to attempt to master them all. But it was different +in those days of beginnings. Then the methods of observation were still +crude, and it was quite the custom for a thinker of forceful personality +to find an eager following among disciples who never thought of putting +his theories to the test of experiment. The great lesson that true +science in the last resort depends upon observation and measurement, +upon compass and balance, had not yet been learned, though here and +there a thinker like Anaxagoras had gained an inkling of it. + +For the moment, indeed, there in Attica, which was now, thanks to that +outburst of Periclean culture, the centre of the world's civilization, +the trend of thought was to take quite another direction. The very year +which saw the birth of Democritus at Abdera, and of Hippocrates, marked +also the birth, at Athens, of another remarkable man, whose influence it +would scarcely be possible to over-estimate. This man was Socrates. The +main facts of his history are familiar to every one. It will be recalled +that Socrates spent his entire life in Athens, mingling everywhere with +the populace; haranguing, so the tradition goes, every one who +would listen; inculcating moral lessons, and finally incurring the +disapprobation of at least a voting majority of his fellow-citizens. He +gathered about him a company of remarkable men with Plato at their head, +but this could not save him from the disapprobation of the multitudes, +at whose hands he suffered death, legally administered after a public +trial. The facts at command as to certain customs of the Greeks at this +period make it possible to raise a question as to whether the alleged +"corruption of youth," with which Socrates was charged, may not have had +a different implication from what posterity has preferred to ascribe +to it. But this thought, almost shocking to the modern mind and seeming +altogether sacrilegious to most students of Greek philosophy, need not +here detain us; neither have we much concern in the present connection +with any part of the teaching of the martyred philosopher. For the +historian of metaphysics, Socrates marks an epoch, but for the historian +of science he is a much less consequential figure. + +Similarly regarding Plato, the aristocratic Athenian who sat at the +feet of Socrates, and through whose writings the teachings of the master +found widest currency. Some students of philosophy find in Plato "the +greatest thinker and writer of all time."(1) The student of science +must recognize in him a thinker whose point of view was essentially +non-scientific; one who tended always to reason from the general to +the particular rather than from the particular to the general. Plato's +writings covered almost the entire field of thought, and his ideas +were presented with such literary charm that successive generations +of readers turned to them with unflagging interest, and gave them wide +currency through copies that finally preserved them to our own time. +Thus we are not obliged in his case, as we are in the case of every +other Greek philosopher, to estimate his teachings largely from hearsay +evidence. Plato himself speaks to us directly. It is true, the literary +form which he always adopted, namely, the dialogue, does not give quite +the same certainty as to when he is expressing his own opinions that +a more direct narrative would have given; yet, in the main, there is +little doubt as to the tenor of his own opinions--except, indeed, such +doubt as always attaches to the philosophical reasoning of the abstract +thinker. + +What is chiefly significant from our present standpoint is that the +great ethical teacher had no significant message to give the world +regarding the physical sciences. He apparently had no sharply defined +opinions as to the mechanism of the universe; no clear conception as to +the origin or development of organic beings; no tangible ideas as to +the problems of physics; no favorite dreams as to the nature of matter. +Virtually his back was turned on this entire field of thought. He was +under the sway of those innate ideas which, as we have urged, were among +the earliest inductions of science. But he never for a moment suspected +such an origin for these ideas. He supposed his conceptions of being, +his standards of ethics, to lie back of all experience; for him they +were the most fundamental and most dependable of facts. He criticised +Anaxagoras for having tended to deduce general laws from observation. As +we moderns see it, such criticism is the highest possible praise. It is +a criticism that marks the distinction between the scientist who is also +a philosopher and the philosopher who has but a vague notion of physical +science. Plato seemed, indeed, to realize the value of scientific +investigation; he referred to the astronomical studies of the Egyptians +and Chaldeans, and spoke hopefully of the results that might accrue +were such studies to be taken up by that Greek mind which, as he justly +conceived, had the power to vitalize and enrich all that it touched. +But he told here of what he would have others do, not of what he himself +thought of doing. His voice was prophetic, but it stimulated no worker +of his own time. + +Plato himself had travelled widely. It is a familiar legend that he +lived for years in Egypt, endeavoring there to penetrate the mysteries +of Egyptian science. It is said even that the rudiments of geometry +which he acquired there influenced all his later teachings. But be that +as it may, the historian of science must recognize in the founder of the +Academy a moral teacher and metaphysical dreamer and sociologist, but +not, in the modern acceptance of the term, a scientist. Those wider +phases of biological science which find their expression in metaphysics, +in ethics, in political economy, lie without our present scope; and +for the development of those subjects with which we are more directly +concerned, Plato, like his master, has a negative significance. + + +ARISTOTLE (384-322 B.C.) + +When we pass to that third great Athenian teacher, Aristotle, the case +is far different. Here was a man whose name was to be received as almost +a synonym for Greek science for more than a thousand years after his +death. All through the Middle Ages his writings were to be accepted as +virtually the last word regarding the problems of nature. We shall see +that his followers actually preferred his mandate to the testimony of +their own senses. We shall see, further, that modern science progressed +somewhat in proportion as it overthrew the Aristotelian dogmas. But the +traditions of seventeen or eighteen centuries are not easily set aside, +and it is perhaps not too much to say that the name of Aristotle stands, +even in our own time, as vaguely representative in the popular mind of +all that was highest and best in the science of antiquity. Yet, perhaps, +it would not be going too far to assert that something like a reversal +of this judgment would be nearer the truth. Aristotle did, indeed, bring +together a great mass of facts regarding animals in his work on natural +history, which, being preserved, has been deemed to entitle its author +to be called the "father of zoology." But there is no reason to suppose +that any considerable portion of this work contained matter that was +novel, or recorded observations that were original with Aristotle; and +the classifications there outlined are at best but a vague foreshadowing +of the elaboration of the science. Such as it is, however, the natural +history stands to the credit of the Stagirite. He must be credited, +too, with a clear enunciation of one most important scientific +doctrine--namely, the doctrine of the spherical figure of the earth. +We have already seen that this theory originated with the Pythagorean +philosophers out in Italy. We have seen, too, that the doctrine had not +made its way in Attica in the time of Anaxagoras. But in the intervening +century it had gained wide currency, else so essentially conservative a +thinker as Aristotle would scarcely have accepted it. He did accept it, +however, and gave the doctrine clearest and most precise expression. +Here are his words:(2) + + +"As to the figure of the earth it must necessarily be spherical.... If +it were not so, the eclipses of the moon would not have such sections +as they have. For in the configurations in the course of a month the +deficient part takes all different shapes; it is straight, and concave, +and convex; but in eclipses it always has the line of divisions +convex; wherefore, since the moon is eclipsed in consequence of the +interposition of the earth, the periphery of the earth must be the cause +of this by having a spherical form. And again, from the appearance of +the stars it is clear, not only that the earth is round, but that its +size is not very large; for when we make a small removal to the south or +the north, the circle of the horizon becomes palpably different, so that +the stars overhead undergo a great change, and are not the same to those +that travel in the north and to the south. For some stars are seen in +Egypt or at Cyprus, but are not seen in the countries to the north of +these; and the stars that in the north are visible while they make +a complete circuit, there undergo a setting. So that from this it is +manifest, not only that the form of the earth is round, but also that it +is a part of a not very large sphere; for otherwise the difference +would not be so obvious to persons making so small a change of place. +Wherefore we may judge that those persons who connect the region in the +neighborhood of the pillars of Hercules with that towards India, and +who assert that in this way the sea is one, do not assert things very +improbable. They confirm this conjecture moreover by the elephants, +which are said to be of the same species towards each extreme; as if +this circumstance was a consequence of the conjunction of the +extremes. The mathematicians who try to calculate the measure of the +circumference, make it amount to four hundred thousand stadia; whence we +collect that the earth is not only spherical, but is not large compared +with the magnitude of the other stars." + +But in giving full meed of praise to Aristotle for the promulgation of +this doctrine of the sphericity of the earth, it must unfortunately be +added that the conservative philosopher paused without taking one other +important step. He could not accept, but, on the contrary, he expressly +repudiated, the doctrine of the earth's motion. We have seen that this +idea also was a part of the Pythagorean doctrine, and we shall have +occasion to dwell more at length on this point in a succeeding chapter. +It has even been contended by some critics that it was the adverse +conviction of the Peripatetic philosopher which, more than any other +single influence, tended to retard the progress of the true doctrine +regarding the mechanism of the heavens. Aristotle accepted the +sphericity of the earth, and that doctrine became a commonplace of +scientific knowledge, and so continued throughout classical antiquity. +But Aristotle rejected the doctrine of the earth's motion, and that +doctrine, though promulgated actively by a few contemporaries and +immediate successors of the Stagirite, was then doomed to sink out of +view for more than a thousand years. If it be a correct assumption that +the influence of Aristotle was, in a large measure, responsible for this +result, then we shall perhaps not be far astray in assuming that +the great founder of the Peripatetic school was, on the whole, more +instrumental in retarding the progress of astronomical science that any +other one man that ever lived. + +The field of science in which Aristotle was pre-eminently a pathfinder +is zoology. His writings on natural history have largely been preserved, +and they constitute by far the most important contribution to the +subject that has come down to us from antiquity. They show us that +Aristotle had gained possession of the widest range of facts regarding +the animal kingdom, and, what is far more important, had attempted to +classify these facts. In so doing he became the founder of systematic +zoology. Aristotle's classification of the animal kingdom was known +and studied throughout the Middle Ages, and, in fact, remained in vogue +until superseded by that of Cuvier in the nineteenth century. It is +not to be supposed that all the terms of Aristotle's classification +originated with him. Some of the divisions are too patent to have +escaped the observation of his predecessors. Thus, for example, the +distinction between birds and fishes as separate classes of animals +is so obvious that it must appeal to a child or to a savage. But +the efforts of Aristotle extended, as we shall see, to less patent +generalizations. At the very outset, his grand division of the animal +kingdom into blood-bearing and bloodless animals implies a very broad +and philosophical conception of the entire animal kingdom. The modern +physiologist does not accept the classification, inasmuch as it is now +known that colorless fluids perform the functions of blood for all the +lower organisms. But the fact remains that Aristotle's grand divisions +correspond to the grand divisions of the Lamarckian system--vertebrates +and invertebrates--which every one now accepts. Aristotle, as we have +said, based his classification upon observation of the blood; Lamarck +was guided by a study of the skeleton. The fact that such diverse +points of view could direct the observer towards the same result gives, +inferentially, a suggestive lesson in what the modern physiologist calls +the homologies of parts of the organism. + +Aristotle divides his so-called blood-bearing animals into five classes: +(1) Four-footed animals that bring forth their young alive; (2) birds; +(3) egg-laying four-footed animals (including what modern naturalists +call reptiles and amphibians); (4) whales and their allies; (5) fishes. +This classification, as will be observed, is not so very far afield +from the modern divisions into mammals, birds, reptiles, amphibians, +and fishes. That Aristotle should have recognized the fundamental +distinction between fishes and the fish-like whales, dolphins, and +porpoises proves the far from superficial character of his studies. +Aristotle knew that these animals breathe by means of lungs and that +they produce living young. He recognized, therefore, their affinity +with his first class of animals, even if he did not, like the modern +naturalist, consider these affinities close enough to justify bringing +the two types together into a single class. + +The bloodless animals were also divided by Aristotle into five +classes--namely: (1) Cephalopoda (the octopus, cuttle-fish, etc.); +(2) weak-shelled animals (crabs, etc.); (3) insects and their allies +(including various forms, such as spiders and centipedes, which the +modern classifier prefers to place by themselves); (4) hard-shelled +animals (clams, oysters, snails, etc.); (5) a conglomerate group of +marine forms, including star-fish, sea-urchins, and various anomalous +forms that were regarded as linking the animal to the vegetable worlds. +This classification of the lower forms of animal life continued in vogue +until Cuvier substituted for it his famous grouping into articulates, +mollusks, and radiates; which grouping in turn was in part superseded +later in the nineteenth century. + +What Aristotle did for the animal kingdom his pupil, Theophrastus, did +in some measure for the vegetable kingdom. Theophrastus, however, was +much less a classifier than his master, and his work on botany, called +The Natural History of Development, pays comparatively slight attention +to theoretical questions. It deals largely with such practicalities +as the making of charcoal, of pitch, and of resin, and the effects +of various plants on the animal organism when taken as foods or as +medicines. In this regard the work of Theophrastus, is more nearly akin +to the natural history of the famous Roman compiler, Pliny. It remained, +however, throughout antiquity as the most important work on its subject, +and it entitles Theophrastus to be called the "father of botany." +Theophrastus deals also with the mineral kingdom after much the same +fashion, and here again his work is the most notable that was produced +in antiquity. + + + + +IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + +We are entering now upon the most important scientific epoch of +antiquity. When Aristotle and Theophrastus passed from the scene, Athens +ceased to be in any sense the scientific centre of the world. That +city still retained its reminiscent glory, and cannot be ignored in the +history of culture, but no great scientific leader was ever again to +be born or to take up his permanent abode within the confines of Greece +proper. With almost cataclysmic suddenness, a new intellectual centre +appeared on the south shore of the Mediterranean. This was the city +of Alexandria, a city which Alexander the Great had founded during his +brief visit to Egypt, and which became the capital of Ptolemy Soter when +he chose Egypt as his portion of the dismembered empire of the great +Macedonian. Ptolemy had been with his master in the East, and was with +him in Babylonia when he died. He had therefore come personally in +contact with Babylonian civilization, and we cannot doubt that this had +a most important influence upon his life, and through him upon the +new civilization of the West. In point of culture, Alexandria must be +regarded as the successor of Babylon, scarcely less directly than of +Greece. Following the Babylonian model, Ptolemy erected a great museum +and began collecting a library. Before his death it was said that he +had collected no fewer than two hundred thousand manuscripts. He had +gathered also a company of great teachers and founded a school of +science which, as has just been said, made Alexandria the culture-centre +of the world. + +Athens in the day of her prime had known nothing quite like this. Such +private citizens as Aristotle are known to have had libraries, but there +were no great public collections of books in Athens, or in any other +part of the Greek domain, until Ptolemy founded his famous library. As +is well known, such libraries had existed in Babylonia for thousands of +years. The character which the Ptolemaic epoch took on was no doubt due +to Babylonian influence, but quite as much to the personal experience +of Ptolemy himself as an explorer in the Far East. The marvellous +conquering journey of Alexander had enormously widened the horizon of +the Greek geographer, and stimulated the imagination of all ranks of the +people, It was but natural, then, that geography and its parent +science astronomy should occupy the attention of the best minds in this +succeeding epoch. In point of fact, such a company of star-gazers and +earth-measurers came upon the scene in this third century B.C. as had +never before existed anywhere in the world. The whole trend of the time +was towards mechanics. It was as if the greatest thinkers had squarely +faced about from the attitude of the mystical philosophers of the +preceding century, and had set themselves the task of solving all the +mechanical riddles of the universe, They no longer troubled themselves +about problems of "being" and "becoming"; they gave but little heed to +metaphysical subtleties; they demanded that their thoughts should be +gauged by objective realities. Hence there arose a succession of great +geometers, and their conceptions were applied to the construction of +new mechanical contrivances on the one hand, and to the elaboration of +theories of sidereal mechanics on the other. + +The wonderful company of men who performed the feats that are about to +be recorded did not all find their home in Alexandria, to be sure; but +they all came more or less under the Alexandrian influence. We shall see +that there are two other important centres; one out in Sicily, almost +at the confines of the Greek territory in the west; the other in Asia +Minor, notably on the island of Samos--the island which, it will be +recalled, was at an earlier day the birthplace of Pythagoras. But +whereas in the previous century colonists from the confines of the +civilized world came to Athens, now all eyes turned towards Alexandria, +and so improved were the facilities for communication that no doubt the +discoveries of one coterie of workers were known to all the others much +more quickly than had ever been possible before. We learn, for example, +that the studies of Aristarchus of Samos were definitely known to +Archimedes of Syracuse, out in Sicily. Indeed, as we shall see, it +is through a chance reference preserved in one of the writings of +Archimedes that one of the most important speculations of Aristarchus is +made known to us. This illustrates sufficiently the intercommunication +through which the thought of the Alexandrian epoch was brought into a +single channel. We no longer, as in the day of the earlier schools of +Greek philosophy, have isolated groups of thinkers. The scientific drama +is now played out upon a single stage; and if we pass, as we shall in +the present chapter, from Alexandria to Syracuse and from Syracuse to +Samos, the shift of scenes does no violence to the dramatic unities. + +Notwithstanding the number of great workers who were not properly +Alexandrians, none the less the epoch is with propriety termed +Alexandrian. Not merely in the third century B.C., but throughout the +lapse of at least four succeeding centuries, the city of Alexander +and the Ptolemies continued to hold its place as the undisputed +culture-centre of the world. During that period Rome rose to its +pinnacle of glory and began to decline, without ever challenging the +intellectual supremacy of the Egyptian city. We shall see, in a +later chapter, that the Alexandrian influences were passed on to the +Mohammedan conquerors, and every one is aware that when Alexandria was +finally overthrown its place was taken by another Greek city, Byzantium +or Constantinople. But that transfer did not occur until Alexandria had +enjoyed a longer period of supremacy as an intellectual centre than +had perhaps ever before been granted to any city, with the possible +exception of Babylon. + + +EUCLID (ABOUT 300 B.C.) + +Our present concern is with that first wonderful development of +scientific activity which began under the first Ptolemy, and which +presents, in the course of the first century of Alexandrian influence, +the most remarkable coterie of scientific workers and thinkers that +antiquity produced. The earliest group of these new leaders in science +had at its head a man whose name has been a household word ever since. +This was Euclid, the father of systematic geometry. Tradition has +preserved to us but little of the personality of this remarkable +teacher; but, on the other hand, his most important work has come down +to us in its entirety. The Elements of Geometry, with which the name +of Euclid is associated in the mind of every school-boy, presented the +chief propositions of its subject in so simple and logical a form that +the work remained a textbook everywhere for more than two thousand +years. Indeed it is only now beginning to be superseded. It is not +twenty years since English mathematicians could deplore the fact that, +despite certain rather obvious defects of the work of Euclid, no better +textbook than this was available. Euclid's work, of course, gives +expression to much knowledge that did not originate with him. We have +already seen that several important propositions of geometry had been +developed by Thales, and one by Pythagoras, and that the rudiments of +the subject were at least as old as Egyptian civilization. Precisely how +much Euclid added through his own investigations cannot be ascertained. +It seems probable that he was a diffuser of knowledge rather than an +originator, but as a great teacher his fame is secure. He is credited +with an epigram which in itself might insure him perpetuity of fame: +"There is no royal road to geometry," was his answer to Ptolemy when +that ruler had questioned whether the Elements might not be simplified. +Doubtless this, like most similar good sayings, is apocryphal; but +whoever invented it has made the world his debtor. + + +HEROPHILUS AND ERASISTRATUS + +The catholicity of Ptolemy's tastes led him, naturally enough, to +cultivate the biological no less than the physical sciences. In +particular his influence permitted an epochal advance in the field of +medicine. Two anatomists became famous through the investigations they +were permitted to make under the patronage of the enlightened ruler. +These earliest of really scientific investigators of the mechanism +of the human body were named Herophilus and Erasistratus. These two +anatomists gained their knowledge by the dissection of human bodies +(theirs are the first records that we have of such practices), and +King Ptolemy himself is said to have been present at some of these +dissections. They were the first to discover that the nerve-trunks have +their origin in the brain and spinal cord, and they are credited +also with the discovery that these nerve-trunks are of two different +kinds--one to convey motor, and the other sensory impulses. They +discovered, described, and named the coverings of the brain. The name of +Herophilus is still applied by anatomists, in honor of the discoverer, +to one of the sinuses or large canals that convey the venous blood +from the head. Herophilus also noticed and described four cavities or +ventricles in the brain, and reached the conclusion that one of these +ventricles was the seat of the soul--a belief shared until comparatively +recent times by many physiologists. He made also a careful and fairly +accurate study of the anatomy of the eye, a greatly improved the old +operation for cataract. + +With the increased knowledge of anatomy came also corresponding advances +in surgery, and many experimental operations are said to have been +performed upon condemned criminals who were handed over to the surgeons +by the Ptolemies. While many modern writers have attempted to discredit +these assertions, it is not improbable that such operations were +performed. In an age when human life was held so cheap, and among a +people accustomed to torturing condemned prisoners for comparatively +slight offences, it is not unlikely that the surgeons were allowed +to inflict perhaps less painful tortures in the cause of science. +Furthermore, we know that condemned criminals were sometimes handed over +to the medical profession to be "operated upon and killed in whatever +way they thought best" even as late as the sixteenth century. +Tertullian(1) probably exaggerates, however, when he puts the number of +such victims in Alexandria at six hundred. + +Had Herophilus and Erasistratus been as happy in their deductions as to +the functions of the organs as they were in their knowledge of anatomy, +the science of medicine would have been placed upon a very high plane +even in their time. Unfortunately, however, they not only drew erroneous +inferences as to the functions of the organs, but also disagreed +radically as to what functions certain organs performed, and how +diseases should be treated, even when agreeing perfectly on the subject +of anatomy itself. Their contribution to the knowledge of the scientific +treatment of diseases holds no such place, therefore, as their +anatomical investigations. + +Half a century after the time of Herophilus there appeared a Greek +physician, Heraclides, whose reputation in the use of drugs far +surpasses that of the anatomists of the Alexandrian school. His +reputation has been handed down through the centuries as that of a +physician, rather than a surgeon, although in his own time he was +considered one of the great surgeons of the period. Heraclides belonged +to the "Empiric" school, which rejected anatomy as useless, depending +entirely on the use of drugs. He is thought to have been the first +physician to point out the value of opium in certain painful diseases. +His prescription of this drug for certain cases of "sleeplessness, +spasm, cholera, and colic," shows that his use of it was not unlike that +of the modern physician in certain cases; and his treatment of fevers, +by keeping the patient's head cool and facilitating the secretions of +the body, is still recognized as "good practice." He advocated a free +use of liquids in quenching the fever patient's thirst--a recognized +therapeutic measure to-day, but one that was widely condemned a century +ago. + + +ARCHIMEDES OF SYRACUSE AND THE FOUNDATION OF MECHANICS + +We do not know just when Euclid died, but as he was at the height of his +fame in the time of Ptolemy I., whose reign ended in the year 285 B.C., +it is hardly probable that he was still living when a young man named +Archimedes came to Alexandria to study. Archimedes was born in the Greek +colony of Syracuse, on the island of Sicily, in the year 287 B.C. When +he visited Alexandria he probably found Apollonius of Perga, the pupil +of Euclid, at the head of the mathematical school there. Just how long +Archimedes remained at Alexandria is not known. When he had satisfied +his curiosity or completed his studies, he returned to Syracuse and +spent his life there, chiefly under the patronage of King Hiero, who +seems fully to have appreciated his abilities. + +Archimedes was primarily a mathematician. Left to his own devices, he +would probably have devoted his entire time to the study of geometrical +problems. But King Hiero had discovered that his protege had wonderful +mechanical ingenuity, and he made good use of this discovery. Under +stress of the king's urgings, the philosopher was led to invent a great +variety of mechanical contrivances, some of them most curious ones. +Antiquity credited him with the invention of more than forty machines, +and it is these, rather than his purely mathematical discoveries, that +gave his name popular vogue both among his contemporaries and with +posterity. Every one has heard of the screw of Archimedes, through which +the paradoxical effect was produced of making water seem to flow up +hill. The best idea of this curious mechanism is obtained if one will +take in hand an ordinary corkscrew, and imagine this instrument to +be changed into a hollow tube, retaining precisely the same shape but +increased to some feet in length and to a proportionate diameter. If one +will hold the corkscrew in a slanting direction and turn it slowly to +the right, supposing that the point dips up a portion of water each time +it revolves, one can in imagination follow the flow of that portion +of water from spiral to spiral, the water always running downward, of +course, yet paradoxically being lifted higher and higher towards +the base of the corkscrew, until finally it pours out (in the actual +Archimedes' tube) at the top. There is another form of the screw in +which a revolving spiral blade operates within a cylinder, but the +principle is precisely the same. With either form water may be lifted, +by the mere turning of the screw, to any desired height. The ingenious +mechanism excited the wonder of the contemporaries of Archimedes, as +well it might. More efficient devices have superseded it in modern +times, but it still excites the admiration of all who examine it, and +its effects seem as paradoxical as ever. + +Some other of the mechanisms of Archimedes have been made known to +successive generations of readers through the pages of Polybius and +Plutarch. These are the devices through which Archimedes aided King +Hiero to ward off the attacks of the Roman general Marcellus, who in the +course of the second Punic war laid siege to Syracuse. + +Plutarch, in his life of Marcellus, describes the Roman's attack and +Archimedes' defence in much detail. Incidentally he tells us also how +Archimedes came to make the devices that rendered the siege so famous: + +"Marcellus himself, with threescore galleys of five rowers at every +bank, well armed and full of all sorts of artillery and fireworks, did +assault by sea, and rowed hard to the wall, having made a great engine +and device of battery, upon eight galleys chained together, to batter +the wall: trusting in the great multitude of his engines of battery, and +to all such other necessary provision as he had for wars, as also in his +own reputation. But Archimedes made light account of all his devices, as +indeed they were nothing comparable to the engines himself had invented. +This inventive art to frame instruments and engines (which are called +mechanical, or organical, so highly commended and esteemed of all sorts +of people) was first set forth by Architas, and by Eudoxus: partly to +beautify a little the science of geometry by this fineness, and partly +to prove and confirm by material examples and sensible instruments, +certain geometrical conclusions, where of a man cannot find out the +conceivable demonstrations by enforced reasons and proofs. As +that conclusion which instructeth one to search out two lines mean +proportional, which cannot be proved by reason demonstrative, and yet +notwithstanding is a principle and an accepted ground for many things +which are contained in the art of portraiture. Both of them have +fashioned it to the workmanship of certain instruments, called mesolabes +or mesographs, which serve to find these mean lines proportional, by +drawing certain curve lines, and overthwart and oblique sections. But +after that Plato was offended with them, and maintained against +them, that they did utterly corrupt and disgrace, the worthiness +and excellence of geometry, making it to descend from things not +comprehensible and without body, unto things sensible and material, and +to bring it to a palpable substance, where the vile and base handiwork +of man is to be employed: since that time, I say, handicraft, or the +art of engines, came to be separated from geometry, and being long time +despised by the philosophers, it came to be one of the warlike arts. + +"But Archimedes having told King Hiero, his kinsman and friend, that +it was possible to remove as great a weight as he would, with as little +strength as he listed to put to it: and boasting himself thus (as they +report of him) and trusting to the force of his reasons, wherewith he +proved this conclusion, that if there were another globe of earth, he +was able to remove this of ours, and pass it over to the other: +King Hiero wondering to hear him, required him to put his device in +execution, and to make him see by experience, some great or heavy weight +removed, by little force. So Archimedes caught hold with a book of one +of the greatest carects, or hulks of the king (that to draw it to the +shore out of the water required a marvellous number of people to go +about it, and was hardly to be done so) and put a great number of men +more into her, than her ordinary burden: and he himself sitting alone +at his ease far off, without any straining at all, drawing the end of an +engine with many wheels and pulleys, fair and softly with his hand, made +it come as gently and smoothly to him, as it had floated in the sea. The +king wondering to see the sight, and knowing by proof the greatness of +his art; be prayed him to make him some engines, both to assault and +defend, in all manner of sieges and assaults. So Archimedes made him +many engines, but King Hiero never occupied any of them, because he +reigned the most part of his time in peace without any wars. But +this provision and munition of engines, served the Syracusan's turn +marvellously at that time: and not only the provision of the engines +ready made, but also the engineer and work-master himself, that had +invented them. + +"Now the Syracusans, seeing themselves assaulted by the Romans, both by +sea and by land, were marvellously perplexed, and could not tell what +to say, they were so afraid: imagining it was impossible for them to +withstand so great an army. But when Archimedes fell to handling his +engines, and to set them at liberty, there flew in the air infinite +kinds of shot, and marvellous great stones, with an incredible noise and +force on the sudden, upon the footmen that came to assault the city by +land, bearing down, and tearing in pieces all those which came against +them, or in what place soever they lighted, no earthly body being able +to resist the violence of so heavy a weight: so that all their ranks +were marvellously disordered. And as for the galleys that gave assault +by sea, some were sunk with long pieces of timber like unto the yards of +ships, whereto they fasten their sails, which were suddenly blown over +the walls with force of their engines into their galleys, and so sunk +them by their over great weight." + + +Polybius describes what was perhaps the most important of these +contrivances, which was, he tells us, "a band of iron, hanging by +a chain from the beak of a machine, which was used in the following +manner. The person who, like a pilot, guided the beak, having let fall +the hand, and catched hold of the prow of any vessel, drew down the +opposite end of the machine that was on the inside of the walls. And +when the vessel was thus raised erect upon its stem, the machine itself +was held immovable; but, the chain being suddenly loosened from the +beak by the means of pulleys, some of the vessels were thrown upon their +sides, others turned with the bottom upwards; and the greatest part, +as the prows were plunged from a considerable height into the sea, were +filled with water, and all that were on board thrown into tumult and +disorder. + +"Marcellus was in no small degree embarrassed," Polybius continues, +"when he found himself encountered in every attempt by such resistance. +He perceived that all his efforts were defeated with loss; and were even +derided by the enemy. But, amidst all the anxiety that he suffered, he +could not help jesting upon the inventions of Archimedes. This man, said +he, employs our ships as buckets to draw water: and boxing about our +sackbuts, as if they were unworthy to be associated with him, drives +them from his company with disgrace. Such was the success of the siege +on the side of the sea." + +Subsequently, however, Marcellus took the city by strategy, and +Archimedes was killed, contrary, it is said, to the express orders +of Marcellus. "Syracuse being taken," says Plutarch, "nothing grieved +Marcellus more than the loss of Archimedes. Who, being in his study when +the city was taken, busily seeking out by himself the demonstration +of some geometrical proposition which he had drawn in figure, and so +earnestly occupied therein, as he neither saw nor heard any noise of +enemies that ran up and down the city, and much less knew it was taken: +he wondered when he saw a soldier by him, that bade him go with him to +Marcellus. Notwithstanding, he spake to the soldier, and bade him tarry +until he had done his conclusion, and brought it to demonstration: but +the soldier being angry with his answer, drew out his sword and killed +him. Others say, that the Roman soldier when he came, offered the +sword's point to him, to kill him: and that Archimedes when he saw him, +prayed him to hold his hand a little, that he might not leave the matter +he looked for imperfect, without demonstration. But the soldier making +no reckoning of his speculation, killed him presently. It is reported +a third way also, saying that certain soldiers met him in the streets +going to Marcellus, carrying certain mathematical instruments in +a little pretty coffer, as dials for the sun, spheres, and angles, +wherewith they measure the greatness of the body of the sun by view: +and they supposing he had carried some gold or silver, or other precious +jewels in that little coffer, slew him for it. But it is most certain +that Marcellus was marvellously sorry for his death, and ever after +hated the villain that slew him, as a cursed and execrable person: and +how he had made also marvellous much afterwards of Archimedes' kinsmen +for his sake." + +We are further indebted to Plutarch for a summary of the character and +influence of Archimedes, and for an interesting suggestion as to the +estimate which the great philosopher put upon the relative importance of +his own discoveries. "Notwithstanding Archimedes had such a great mind, +and was so profoundly learned, having hidden in him the only treasure +and secrets of geometrical inventions: as he would never set forth any +book how to make all these warlike engines, which won him at that time +the fame and glory, not of man's knowledge, but rather of divine wisdom. +But he esteeming all kind of handicraft and invention to make engines, +and generally all manner of sciences bringing common commodity by the +use of them, to be but vile, beggarly, and mercenary dross: employed his +wit and study only to write things, the beauty and subtlety whereof +were not mingled anything at all with necessity. For all that he hath +written, are geometrical propositions, which are without comparison of +any other writings whatsoever: because the subject where of they treat, +doth appear by demonstration, the maker gives them the grace and +the greatness, and the demonstration proving it so exquisitely, with +wonderful reason and facility, as it is not repugnable. For in all +geometry are not to be found more profound and difficult matters +written, in more plain and simple terms, and by more easy principles, +than those which he hath invented. Now some do impute this, to the +sharpness of his wit and understanding, which was a natural gift in him: +others do refer it to the extreme pains he took, which made these things +come so easily from him, that they seemed as if they had been no trouble +to him at all. For no man living of himself can devise the demonstration +of his propositions, what pains soever he take to seek it: and yet +straight so soon as he cometh to declare and open it, every man then +imagineth with himself he could have found it out well enough, he can +then so plainly make demonstration of the thing he meaneth to show. And +therefore that methinks is likely to be true, which they write of him: +that he was so ravished and drunk with the sweet enticements of this +siren, which as it were lay continually with him, as he forgot his meat +and drink, and was careless otherwise of himself, that oftentimes his +servants got him against his will to the baths to wash and anoint him: +and yet being there, he would ever be drawing out of the geometrical +figures, even in the very imbers of the chimney. And while they were +anointing of him with oils and sweet savours, with his finger he did +draw lines upon his naked body: so far was he taken from himself, and +brought into an ecstasy or trance, with the delight he had in the study +of geometry, and truly ravished with the love of the Muses. But amongst +many notable things he devised, it appeareth, that he most esteemed the +demonstration of the proportion between the cylinder (to wit, the round +column) and the sphere or globe contained in the same: for he prayed his +kinsmen and friends, that after his death they would put a cylinder +upon his tomb, containing a massy sphere, with an inscription of the +proportion, whereof the continent exceedeth the thing contained."(2) + +It should be observed that neither Polybius nor Plutarch mentions the +use of burning-glasses in connection with the siege of Syracuse, nor +indeed are these referred to by any other ancient writer of authority. +Nevertheless, a story gained credence down to a late day to the effect +that Archimedes had set fire to the fleet of the enemy with the aid of +concave mirrors. An experiment was made by Sir Isaac Newton to show +the possibility of a phenomenon so well in accord with the genius of +Archimedes, but the silence of all the early authorities makes it more +than doubtful whether any such expedient was really adopted. + +It will be observed that the chief principle involved in all these +mechanisms was a capacity to transmit great power through levers and +pulleys, and this brings us to the most important field of the Syracusan +philosopher's activity. It was as a student of the lever and the pulley +that Archimedes was led to some of his greatest mechanical discoveries. +He is even credited with being the discoverer of the compound pulley. +More likely he was its developer only, since the principle of the pulley +was known to the old Babylonians, as their sculptures testify. But there +is no reason to doubt the general outlines of the story that Archimedes +astounded King Hiero by proving that, with the aid of multiple pulleys, +the strength of one man could suffice to drag the largest ship from its +moorings. + +The property of the lever, from its fundamental principle, was studied +by him, beginning with the self-evident fact that "equal bodies at the +ends of the equal arms of a rod, supported on its middle point, will +balance each other"; or, what amounts to the same thing stated in +another way, a regular cylinder of uniform matter will balance at its +middle point. From this starting-point he elaborated the subject on such +clear and satisfactory principles that they stand to-day practically +unchanged and with few additions. From all his studies and experiments +he finally formulated the principle that "bodies will be in equilibrio +when their distance from the fulcrum or point of support is inversely as +their weight." He is credited with having summed up his estimate of the +capabilities of the lever with the well-known expression, "Give me a +fulcrum on which to rest or a place on which to stand, and I will move +the earth." + +But perhaps the feat of all others that most appealed to the imagination +of his contemporaries, and possibly also the one that had the greatest +bearing upon the position of Archimedes as a scientific discoverer, +was the one made familiar through the tale of the crown of Hiero. This +crown, so the story goes, was supposed to be made of solid gold, but +King Hiero for some reason suspected the honesty of the jeweller, and +desired to know if Archimedes could devise a way of testing the question +without injuring the crown. Greek imagination seldom spoiled a story in +the telling, and in this case the tale was allowed to take on the most +picturesque of phases. The philosopher, we are assured, pondered the +problem for a long time without succeeding, but one day as he stepped +into a bath, his attention was attracted by the overflow of water. A +new train of ideas was started in his ever-receptive brain. Wild with +enthusiasm he sprang from the bath, and, forgetting his robe, dashed +along the streets of Syracuse, shouting: "Eureka! Eureka!" (I have found +it!) The thought that had come into his mind was this: That any heavy +substance must have a bulk proportionate to its weight; that gold and +silver differ in weight, bulk for bulk, and that the way to test the +bulk of such an irregular object as a crown was to immerse it in water. +The experiment was made. A lump of pure gold of the weight of the crown +was immersed in a certain receptacle filled with water, and the overflow +noted. Then a lump of pure silver of the same weight was similarly +immersed; lastly the crown itself was immersed, and of course--for the +story must not lack its dramatic sequel--was found bulkier than its +weight of pure gold. Thus the genius that could balk warriors and armies +could also foil the wiles of the silversmith. + +Whatever the truth of this picturesque narrative, the fact remains that +some, such experiments as these must have paved the way for perhaps +the greatest of all the studies of Archimedes--those that relate to the +buoyancy of water. Leaving the field of fable, we must now examine these +with some precision. Fortunately, the writings of Archimedes himself +are still extant, in which the results of his remarkable experiments are +related, so we may present the results in the words of the discoverer. + +Here they are: "First: The surface of every coherent liquid in a state +of rest is spherical, and the centre of the sphere coincides with the +centre of the earth. Second: A solid body which, bulk for bulk, is of +the same weight as a liquid, if immersed in the liquid will sink so that +the surface of the body is even with the surface of the liquid, but will +not sink deeper. Third: Any solid body which is lighter, bulk for bulk, +than a liquid, if placed in the liquid will sink so deep as to displace +the mass of liquid equal in weight to another body. Fourth: If a body +which is lighter than a liquid is forcibly immersed in the liquid, it +will be pressed upward with a force corresponding to the weight of a +like volume of water, less the weight of the body itself. Fifth: Solid +bodies which, bulk for bulk, are heavier than a liquid, when immersed in +the liquid sink to the bottom, but become in the liquid as much lighter +as the weight of the displaced water itself differs from the weight of +the solid." These propositions are not difficult to demonstrate, once +they are conceived, but their discovery, combined with the discovery +of the laws of statics already referred to, may justly be considered as +proving Archimedes the most inventive experimenter of antiquity. + +Curiously enough, the discovery which Archimedes himself is said to have +considered the most important of all his innovations is one that seems +much less striking. It is the answer to the question, What is the +relation in bulk between a sphere and its circumscribing cylinder? +Archimedes finds that the ratio is simply two to three. We are not +informed as to how he reached his conclusion, but an obvious method +would be to immerse a ball in a cylindrical cup. The experiment is one +which any one can make for himself, with approximate accuracy, with the +aid of a tumbler and a solid rubber ball or a billiard-ball of just the +right size. Another geometrical problem which Archimedes solved was the +problem as to the size of a triangle which has equal area with a circle; +the answer being, a triangle having for its base the circumference of +the circle and for its altitude the radius. Archimedes solved also +the problem of the relation of the diameter of the circle to its +circumference; his answer being a close approximation to the familiar +3.1416, which every tyro in geometry will recall as the equivalent of +pi. + +Numerous other of the studies of Archimedes having reference to conic +sections, properties of curves and spirals, and the like, are too +technical to be detailed here. The extent of his mathematical knowledge, +however, is suggested by the fact that he computed in great detail the +number of grains of sand that would be required to cover the sphere of +the sun's orbit, making certain hypothetical assumptions as to the size +of the earth and the distance of the sun for the purposes of argument. +Mathematicians find his computation peculiarly interesting because it +evidences a crude conception of the idea of logarithms. From our present +stand-point, the paper in which this calculation is contained has +considerable interest because of its assumptions as to celestial +mechanics. Thus Archimedes starts out with the preliminary assumption +that the circumference of the earth is less than three million stadia. +It must be understood that this assumption is purely for the sake of +argument. Archimedes expressly states that he takes this number because +it is "ten times as large as the earth has been supposed to be by +certain investigators." Here, perhaps, the reference is to Eratosthenes, +whose measurement of the earth we shall have occasion to revert to in a +moment. Continuing, Archimedes asserts that the sun is larger than the +earth, and the earth larger than the moon. In this assumption, he says, +he is following the opinion of the majority of astronomers. In the third +place, Archimedes assumes that the diameter of the sun is not more than +thirty times greater than that of the moon. Here he is probably basing +his argument upon another set of measurements of Aristarchus, to +which, also, we shall presently refer more at length. In reality, his +assumption is very far from the truth, since the actual diameter of the +sun, as we now know, is something like four hundred times that of the +moon. Fourth, the circumference of the sun is greater than one side of +the thousand-faced figure inscribed in its orbit. The measurement, it is +expressly stated, is based on the measurements of Aristarchus, who makes +the diameter of the sun 1/170 of its orbit. Archimedes adds, however, +that he himself has measured the angle and that it appears to him to be +less than 1/164, and greater than 1/200 part of the orbit. That is to +say, reduced to modern terminology, he places the limit of the sun's +apparent size between thirty-three minutes and twenty-seven minutes of +arc. As the real diameter is thirty-two minutes, this calculation is +surprisingly exact, considering the implements then at command. But +the honor of first making it must be given to Aristarchus and not to +Archimedes. + +We need not follow Archimedes to the limits of his incomprehensible +numbers of sand-grains. The calculation is chiefly remarkable because +it was made before the introduction of the so-called Arabic numerals +had simplified mathematical calculations. It will be recalled that the +Greeks used letters for numerals, and, having no cipher, they soon found +themselves in difficulties when large numbers were involved. The Roman +system of numerals simplified the matter somewhat, but the beautiful +simplicity of the decimal system did not come into vogue until the +Middle Ages, as we shall see. Notwithstanding the difficulties, however, +Archimedes followed out his calculations to the piling up of bewildering +numbers, which the modern mathematician finds to be the consistent +outcome of the problem he had set himself. + +But it remains to notice the most interesting feature of this document +in which the calculation of the sand-grains is contained. "It was +known to me," says Archimedes, "that most astronomers understand by the +expression 'world' (universe) a ball of which the centre is the middle +point of the earth, and of which the radius is a straight line between +the centre of the earth and the sun." Archimedes himself appears to +accept this opinion of the majority,--it at least serves as well as the +contrary hypothesis for the purpose of his calculation,--but he goes on +to say: "Aristarchus of Samos, in his writing against the astronomers, +seeks to establish the fact that the world is really very different +from this. He holds the opinion that the fixed stars and the sun are +immovable and that the earth revolves in a circular line about the sun, +the sun being at the centre of this circle." This remarkable bit of +testimony establishes beyond question the position of Aristarchus of +Samos as the Copernicus of antiquity. We must make further inquiry as to +the teachings of the man who had gained such a remarkable insight into +the true system of the heavens. + + +ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY + +It appears that Aristarchus was a contemporary of Archimedes, but the +exact dates of his life are not known. He was actively engaged in making +astronomical observations in Samos somewhat before the middle of the +third century B.C.; in other words, just at the time when the activities +of the Alexandrian school were at their height. Hipparchus, at a later +day, was enabled to compare his own observations with those made by +Aristarchus, and, as we have just seen, his work was well known to so +distant a contemporary as Archimedes. Yet the facts of his life are +almost a blank for us, and of his writings only a single one has been +preserved. That one, however, is a most important and interesting paper +on the measurements of the sun and the moon. Unfortunately, this paper +gives us no direct clew as to the opinions of Aristarchus concerning the +relative positions of the earth and sun. But the testimony of Archimedes +as to this is unequivocal, and this testimony is supported by other +rumors in themselves less authoritative. + +In contemplating this astronomer of Samos, then, we are in the presence +of a man who had solved in its essentials the problem of the mechanism +of the solar system. It appears from the words of Archimedes +that Aristarchus; had propounded his theory in explicit writings. +Unquestionably, then, he held to it as a positive doctrine, not as a +mere vague guess. We shall show, in a moment, on what grounds he based +his opinion. Had his teaching found vogue, the story of science would be +very different from what it is. We should then have no tale to tell of +a Copernicus coming upon the scene fully seventeen hundred years later +with the revolutionary doctrine that our world is not the centre of the +universe. We should not have to tell of the persecution of a Bruno or +of a Galileo for teaching this doctrine in the seventeenth century of +an era which did not begin till two hundred years after the death of +Aristarchus. But, as we know, the teaching of the astronomer of Samos +did not win its way. The old conservative geocentric doctrine, seemingly +so much more in accordance with the every-day observations of +mankind, supported by the majority of astronomers with the Peripatetic +philosophers at their head, held its place. It found fresh supporters +presently among the later Alexandrians, and so fully eclipsed the +heliocentric view that we should scarcely know that view had even found +an advocate were it not for here and there such a chance record as the +phrases we have just quoted from Archimedes. Yet, as we now see, the +heliocentric doctrine, which we know to be true, had been thought out +and advocated as the correct theory of celestial mechanics by at least +one worker of the third century B.C. Such an idea, we may be sure, did +not spring into the mind of its originator except as the culmination of +a long series of observations and inferences. The precise character of +the evolution we perhaps cannot trace, but its broader outlines are open +to our observation, and we may not leave so important a topic without at +least briefly noting them. + +Fully to understand the theory of Aristarchus, we must go back a century +or two and recall that as long ago as the time of that other great +native of Samos, Pythagoras, the conception had been reached that the +earth is in motion. We saw, in dealing with Pythagoras, that we could +not be sure as to precisely what he himself taught, but there is no +question that the idea of the world's motion became from an early day a +so-called Pythagorean doctrine. While all the other philosophers, so far +as we know, still believed that the world was flat, the Pythagoreans out +in Italy taught that the world is a sphere and that the apparent motions +of the heavenly bodies are really due to the actual motion of the earth +itself. They did not, however, vault to the conclusion that this true +motion of the earth takes place in the form of a circuit about the sun. +Instead of that, they conceived the central body of the universe to be a +great fire, invisible from the earth, because the inhabited side of the +terrestrial ball was turned away from it. The sun, it was held, is but +a great mirror, which reflects the light from the central fire. Sun +and earth alike revolve about this great fire, each in its own orbit. +Between the earth and the central fire there was, curiously enough, +supposed to be an invisible earthlike body which was given the name +of Anticthon, or counter-earth. This body, itself revolving about the +central fire, was supposed to shut off the central light now and again +from the sun or from the moon, and thus to account for certain eclipses +for which the shadow of the earth did not seem responsible. It was, +perhaps, largely to account for such eclipses that the counter-earth +was invented. But it is supposed that there was another reason. The +Pythagoreans held that there is a peculiar sacredness in the number ten. +Just as the Babylonians of the early day and the Hegelian philosophers +of a more recent epoch saw a sacred connection between the number seven +and the number of planetary bodies, so the Pythagoreans thought that the +universe must be arranged in accordance with the number ten. Their count +of the heavenly bodies, including the sphere of the fixed stars, seemed +to show nine, and the counter-earth supplied the missing body. + +The precise genesis and development of this idea cannot now be followed, +but that it was prevalent about the fifth century B.C. as a Pythagorean +doctrine cannot be questioned. Anaxagoras also is said to have taken +account of the hypothetical counter-earth in his explanation of +eclipses; though, as we have seen, he probably did not accept that +part of the doctrine which held the earth to be a sphere. The names +of Philolaus and Heraclides have been linked with certain of these +Pythagorean doctrines. Eudoxus, too, who, like the others, lived in Asia +Minor in the fourth century B.C., was held to have made special studies +of the heavenly spheres and perhaps to have taught that the earth moves. +So, too, Nicetas must be named among those whom rumor credited with +having taught that the world is in motion. In a word, the evidence, so +far as we can garner it from the remaining fragments, tends to show that +all along, from the time of the early Pythagoreans, there had been an +undercurrent of opinion in the philosophical world which questioned the +fixity of the earth; and it would seem that the school of thinkers who +tended to accept the revolutionary view centred in Asia Minor, not far +from the early home of the founder of the Pythagorean doctrines. It +was not strange, then, that the man who was finally to carry these new +opinions to their logical conclusion should hail from Samos. + +But what was the support which observation could give to this new, +strange conception that the heavenly bodies do not in reality move as +they seem to move, but that their apparent motion is due to the actual +revolution of the earth? It is extremely difficult for any one nowadays +to put himself in a mental position to answer this question. We are so +accustomed to conceive the solar system as we know it to be, that we +are wont to forget how very different it is from what it seems. Yet one +needs but to glance up at the sky, and then to glance about one at the +solid earth, to grant, on a moment's reflection, that the geocentric +idea is of all others the most natural; and that to conceive the sun +as the actual Centre of the solar system is an idea which must look for +support to some other evidence than that which ordinary observation can +give. Such was the view of most of the ancient philosophers, and such +continued to be the opinion of the majority of mankind long after the +time of Copernicus. We must not forget that even so great an observing +astronomer as Tycho Brahe, so late as the seventeenth century, declined +to accept the heliocentric theory, though admitting that all the planets +except the earth revolve about the sun. We shall see that before the +Alexandrian school lost its influence a geocentric scheme had been +evolved which fully explained all the apparent motions of the heavenly +bodies. All this, then, makes us but wonder the more that the genius of +an Aristarchus could give precedence to scientific induction as against +the seemingly clear evidence of the senses. + +What, then, was the line of scientific induction that led Aristarchus to +this wonderful goal? Fortunately, we are able to answer that query, at +least in part. Aristarchus gained his evidence through some wonderful +measurements. First, he measured the disks of the sun and the moon. +This, of course, could in itself give him no clew to the distance of +these bodies, and therefore no clew as to their relative size; but in +attempting to obtain such a clew he hit upon a wonderful yet altogether +simple experiment. It occurred to him that when the moon is precisely +dichotomized--that is to say, precisely at the half-the line of vision +from the earth to the moon must be precisely at right angles with the +line of light passing from the sun to the moon. At this moment, then, +the imaginary lines joining the sun, the moon, and the earth, make a +right angle triangle. But the properties of the right-angle triangle had +long been studied and were well under stood. One acute angle of such a +triangle determines the figure of the triangle itself. We have already +seen that Thales, the very earliest of the Greek philosophers, measured +the distance of a ship at sea by the application of this principle. Now +Aristarchus sights the sun in place of Thales' ship, and, sighting the +moon at the same time, measures the angle and establishes the shape of +his right-angle triangle. This does not tell him the distance of the +sun, to be sure, for he does not know the length of his base-line--that +is to say, of the line between the moon and the earth. But it does +establish the relation of that base-line to the other lines of the +triangle; in other words, it tells him the distance of the sun in terms +of the moon's distance. As Aristarchus strikes the angle, it shows that +the sun is eighteen times as distant as the moon. Now, by comparing the +apparent size of the sun with the apparent size of the moon--which, as +we have seen, Aristarchus has already measured--he is able to tell us +that, the sun is "more than 5832 times, and less than 8000" times larger +than the moon; though his measurements, taken by themselves, give +no clew to the actual bulk of either body. These conclusions, be it +understood, are absolutely valid inferences--nay, demonstrations--from +the measurements involved, provided only that these measurements have +been correct. Unfortunately, the angle of the triangle we have just seen +measured is exceedingly difficult to determine with accuracy, while at +the same time, as a moment's reflection will show, it is so large an +angle that a very slight deviation from the truth will greatly affect +the distance at which its line joins the other side of the triangle. +Then again, it is virtually impossible to tell the precise moment when +the moon is at half, as the line it gives is not so sharp that we can +fix it with absolute accuracy. There is, moreover, another element of +error due to the refraction of light by the earth's atmosphere. The +experiment was probably made when the sun was near the horizon, at which +time, as we now know, but as Aristarchus probably did not suspect, the +apparent displacement of the sun's position is considerable; and this +displacement, it will be observed, is in the direction to lessen the +angle in question. + +In point of fact, Aristarchus estimated the angle at eighty-seven +degrees. Had his instrument been more precise, and had he been able +to take account of all the elements of error, he would have found +it eighty-seven degrees and fifty-two minutes. The difference of +measurement seems slight; but it sufficed to make the computations +differ absurdly from the truth. The sun is really not merely eighteen +times but more than two hundred times the distance of the moon, as +Wendelein discovered on repeating the experiment of Aristarchus about +two thousand years later. Yet this discrepancy does not in the least +take away from the validity of the method which Aristarchus employed. +Moreover, his conclusion, stated in general terms, was perfectly +correct: the sun is many times more distant than the moon and vastly +larger than that body. Granted, then, that the moon is, as Aristarchus +correctly believed, considerably less in size than the earth, the +sun must be enormously larger than the earth; and this is the vital +inference which, more than any other, must have seemed to Aristarchus +to confirm the suspicion that the sun and not the earth is the centre +of the planetary system. It seemed to him inherently improbable that an +enormously large body like the sun should revolve about a small one such +as the earth. And again, it seemed inconceivable that a body so distant +as the sun should whirl through space so rapidly as to make the circuit +of its orbit in twenty-four hours. But, on the other hand, that a +small body like the earth should revolve about the gigantic sun seemed +inherently probable. This proposition granted, the rotation of the earth +on its axis follows as a necessary consequence in explanation of the +seeming motion of the stars. Here, then, was the heliocentric doctrine +reduced to a virtual demonstration by Aristarchus of Samos, somewhere +about the middle of the third century B.C. + +It must be understood that in following out the steps of reasoning by +which we suppose Aristarchus to have reached so remarkable a conclusion, +we have to some extent guessed at the processes of thought-development; +for no line of explication written by the astronomer himself on this +particular point has come down to us. There does exist, however, as we +have already stated, a very remarkable treatise by Aristarchus on the +Size and Distance of the Sun and the Moon, which so clearly suggests the +methods of reasoning of the great astronomer, and so explicitly cites +the results of his measurements, that we cannot well pass it by +without quoting from it at some length. It is certainly one of the most +remarkable scientific documents of antiquity. As already noted, the +heliocentric doctrine is not expressly stated here. It seems to be +tacitly implied throughout, but it is not a necessary consequence of any +of the propositions expressly stated. These propositions have to do with +certain observations and measurements and what Aristarchus believes to +be inevitable deductions from them, and he perhaps did not wish to have +these deductions challenged through associating them with a theory which +his contemporaries did not accept. In a word, the paper of Aristarchus +is a rigidly scientific document unvitiated by association with any +theorizings that are not directly germane to its central theme. The +treatise opens with certain hypotheses as follows: + +"First. The moon receives its light from the sun. + +"Second. The earth may be considered as a point and as the centre of the +orbit of the moon. + +"Third. When the moon appears to us dichotomized it offers to our view a +great circle (or actual meridian) of its circumference which divides the +illuminated part from the dark part. + +"Fourth. When the moon appears dichotomized its distance from the sun is +less than a quarter of the circumference (of its orbit) by a thirtieth +part of that quarter." + +That is to say, in modern terminology, the moon at this time lacks three +degrees (one thirtieth of ninety degrees) of being at right angles with +the line of the sun as viewed from the earth; or, stated otherwise, the +angular distance of the moon from the sun as viewed from the earth is at +this time eighty-seven degrees--this being, as we have already observed, +the fundamental measurement upon which so much depends. We may fairly +suppose that some previous paper of Aristarchus's has detailed the +measurement which here is taken for granted, yet which of course could +depend solely on observation. + +"Fifth. The diameter of the shadow (cast by the earth at the point where +the moon's orbit cuts that shadow when the moon is eclipsed) is double +the diameter of the moon." + +Here again a knowledge of previously established measurements is taken +for granted; but, indeed, this is the case throughout the treatise. + +"Sixth. The arc subtended in the sky by the moon is a fifteenth part +of a sign" of the zodiac; that is to say, since there are twenty-four, +signs in the zodiac, one-fifteenth of one twenty-fourth, or in modern +terminology, one degree of arc. This is Aristarchus's measurement of the +moon to which we have already referred when speaking of the measurements +of Archimedes. + +"If we admit these six hypotheses," Aristarchus continues, "it follows +that the sun is more than eighteen times more distant from the earth +than is the moon, and that it is less than twenty times more distant, +and that the diameter of the sun bears a corresponding relation to the +diameter of the moon; which is proved by the position of the moon when +dichotomized. But the ratio of the diameter of the sun to that of the +earth is greater than nineteen to three and less than forty-three to +six. This is demonstrated by the relation of the distances, by the +position (of the moon) in relation to the earth's shadow, and by the +fact that the arc subtended by the moon is a fifteenth part of a sign." + +Aristarchus follows with nineteen propositions intended to elucidate +his hypotheses and to demonstrate his various contentions. These show a +singularly clear grasp of geometrical problems and an altogether correct +conception of the general relations as to size and position of the +earth, the moon, and the sun. His reasoning has to do largely with +the shadow cast by the earth and by the moon, and it presupposes +a considerable knowledge of the phenomena of eclipses. His first +proposition is that "two equal spheres may always be circumscribed in +a cylinder; two unequal spheres in a cone of which the apex is found on +the side of the smaller sphere; and a straight line joining the centres +of these spheres is perpendicular to each of the two circles made by the +contact of the surface of the cylinder or of the cone with the spheres." + +It will be observed that Aristarchus has in mind here the moon, the +earth, and the sun as spheres to be circumscribed within a cone, +which cone is made tangible and measurable by the shadows cast by the +non-luminous bodies; since, continuing, he clearly states in proposition +nine, that "when the sun is totally eclipsed, an observer on the earth's +surface is at an apex of a cone comprising the moon and the sun." +Various propositions deal with other relations of the shadows which need +not detain us since they are not fundamentally important, and we +may pass to the final conclusions of Aristarchus, as reached in his +propositions ten to nineteen. + +Now, since (proposition ten) "the diameter of the sun is more than +eighteen times and less than twenty times greater than that of the +moon," it follows (proposition eleven) "that the bulk of the sun is to +that of the moon in ratio, greater than 5832 to 1, and less than 8000 to +1." + +"Proposition sixteen. The diameter of the sun is to the diameter of +the earth in greater proportion than nineteen to three, and less than +forty-three to six. + +"Proposition seventeen. The bulk of the sun is to that of the earth in +greater proportion than 6859 to 27, and less than 79,507 to 216. + +"Proposition eighteen. The diameter of the earth is to the diameter of +the moon in greater proportion than 108 to 43 and less than 60 to 19. + +"Proposition nineteen. The bulk of the earth is to that of the moon +in greater proportion than 1,259,712 to 79,507 and less than 20,000 to +6859." + +Such then are the more important conclusions of this very remarkable +paper--a paper which seems to have interest to the successors of +Aristarchus generation after generation, since this alone of all the +writings of the great astronomer has been preserved. How widely the +exact results of the measurements of Aristarchus, differ from the truth, +we have pointed out as we progressed. But let it be repeated that this +detracts little from the credit of the astronomer who had such clear +and correct conceptions of the relations of the heavenly bodies and who +invented such correct methods of measurement. Let it be particularly +observed, however, that all the conclusions of Aristarchus are stated in +relative terms. He nowhere attempts to estimate the precise size of +the earth, of the moon, or of the sun, or the actual distance of one of +these bodies from another. The obvious reason for this is that no +data were at hand from which to make such precise measurements. Had +Aristarchus known the size of any one of the bodies in question, he +might readily, of course, have determined the size of the others by +the mere application of his relative scale; but he had no means of +determining the size of the earth, and to this extent his system of +measurements remained imperfect. Where Aristarchus halted, however, +another worker of the same period took the task in hand and by an +altogether wonderful measurement determined the size of the earth, and +thus brought the scientific theories of cosmology to their climax. +This worthy supplementor of the work of Aristarchus was Eratosthenes of +Alexandria. + + +ERATOSTHENES, "THE SURVEYOR OF THE WORLD" + +An altogether remarkable man was this native of Cyrene, who came to +Alexandria from Athens to be the chief librarian of Ptolemy Euergetes. +He was not merely an astronomer and a geographer, but a poet and +grammarian as well. His contemporaries jestingly called him Beta the +Second, because he was said through the universality of his attainments +to be "a second Plato" in philosophy, "a second Thales" in astronomy, +and so on throughout the list. He was also called the "surveyor of the +world," in recognition of his services to geography. Hipparchus said +of him, perhaps half jestingly, that he had studied astronomy as a +geographer and geography as an astronomer. It is not quite clear whether +the epigram was meant as compliment or as criticism. Similar phrases +have been turned against men of versatile talent in every age. Be that +as it may, Eratosthenes passed into history as the father of scientific +geography and of scientific chronology; as the astronomer who first +measured the obliquity of the ecliptic; and as the inventive genius +who performed the astounding feat of measuring the size of the globe +on which we live at a time when only a relatively small portion of +that globe's surface was known to civilized man. It is no discredit to +approach astronomy as a geographer and geography as an astronomer if the +results are such as these. What Eratosthenes really did was to approach +both astronomy and geography from two seemingly divergent points of +attack--namely, from the stand-point of the geometer and also from that +of the poet. Perhaps no man in any age has brought a better combination +of observing and imaginative faculties to the aid of science. + +Nearly all the discoveries of Eratosthenes are associated with +observations of the shadows cast by the sun. We have seen that, in the +study of the heavenly bodies, much depends on the measurement of angles. +Now the easiest way in which angles can be measured, when solar angles +are in question, is to pay attention, not to the sun itself, but to +the shadow that it casts. We saw that Thales made some remarkable +measurements with the aid of shadows, and we have more than once +referred to the gnomon, which is the most primitive, but which long +remained the most important, of astronomical instruments. It is believed +that Eratosthenes invented an important modification of the gnomon which +was elaborated afterwards by Hipparchus and called an armillary sphere. +This consists essentially of a small gnomon, or perpendicular post, +attached to a plane representing the earth's equator and a hemisphere in +imitation of the earth's surface. With the aid of this, the shadow +cast by the sun could be very accurately measured. It involves no new +principle. Every perpendicular post or object of any kind placed in the +sunlight casts a shadow from which the angles now in question could be +roughly measured. The province of the armillary sphere was to make these +measurements extremely accurate. + +With the aid of this implement, Eratosthenes carefully noted the longest +and the shortest shadows cast by the gnomon--that is to say, the shadows +cast on the days of the solstices. He found that the distance between +the tropics thus measured represented 47 degrees 42' 39" of arc. +One-half of this, or 23 degrees 5,' 19.5", represented the obliquity of +the ecliptic--that is to say, the angle by which the earth's axis dipped +from the perpendicular with reference to its orbit. This was a most +important observation, and because of its accuracy it has served modern +astronomers well for comparison in measuring the trifling change due to +our earth's slow, swinging wobble. For the earth, be it understood, like +a great top spinning through space, holds its position with relative but +not quite absolute fixity. It must not be supposed, however, that +the experiment in question was quite new with Eratosthenes. His merit +consists rather in the accuracy with which he made his observation than +in the novelty of the conception; for it is recorded that Eudoxus, a +full century earlier, had remarked the obliquity of the ecliptic. That +observer had said that the obliquity corresponded to the side of a +pentadecagon, or fifteen-sided figure, which is equivalent in modern +phraseology to twenty-four degrees of arc. But so little is known +regarding the way in which Eudoxus reached his estimate that the +measurement of Eratosthenes is usually spoken of as if it were the first +effort of the kind. + +Much more striking, at least in its appeal to the popular imagination, +was that other great feat which Eratosthenes performed with the aid +of his perfected gnomon--the measurement of the earth itself. When we +reflect that at this period the portion of the earth open to observation +extended only from the Straits of Gibraltar on the west to India on +the east, and from the North Sea to Upper Egypt, it certainly seems +enigmatical--at first thought almost miraculous--that an observer +should have been able to measure the entire globe. That he should have +accomplished this through observation of nothing more than a tiny bit of +Egyptian territory and a glimpse of the sun's shadow makes it seem but +the more wonderful. Yet the method of Eratosthenes, like many another +enigma, seems simple enough once it is explained. It required but the +application of a very elementary knowledge of the geometry of circles, +combined with the use of a fact or two from local geography--which +detracts nothing from the genius of the man who could reason from such +simple premises to so wonderful a conclusion. + +Stated in a few words, the experiment of Eratosthenes was this. His +geographical studies had taught him that the town of Syene lay directly +south of Alexandria, or, as we should say, on the same meridian of +latitude. He had learned, further, that Syene lay directly under the +tropic, since it was reported that at noon on the day of the summer +solstice the gnomon there cast no shadow, while a deep well was +illumined to the bottom by the sun. A third item of knowledge, supplied +by the surveyors of Ptolemy, made the distance between Syene and +Alexandria five thousand stadia. These, then, were the preliminary data +required by Eratosthenes. Their significance consists in the fact +that here is a measured bit of the earth's arc five thousand stadia in +length. If we could find out what angle that bit of arc subtends, a mere +matter of multiplication would give us the size of the earth. But how +determine this all-important number? The answer came through reflection +on the relations of concentric circles. If you draw any number of +circles, of whatever size, about a given centre, a pair of radii drawn +from that centre will cut arcs of the same relative size from all the +circles. One circle may be so small that the actual arc subtended by the +radii in a given case may be but an inch in length, while another circle +is so large that its corresponding are is measured in millions of miles; +but in each case the same number of so-called degrees will represent the +relation of each arc to its circumference. Now, Eratosthenes knew, as +just stated, that the sun, when on the meridian on the day of the summer +solstice, was directly over the town of Syene. This meant that at that +moment a radius of the earth projected from Syene would point directly +towards the sun. Meanwhile, of course, the zenith would represent the +projection of the radius of the earth passing through Alexandria. All +that was required, then, was to measure, at Alexandria, the angular +distance of the sun from the zenith at noon on the day of the +solstice to secure an approximate measurement of the arc of the +sun's circumference, corresponding to the arc of the earth's surface +represented by the measured distance between Alexandria and Syene. + +The reader will observe that the measurement could not be absolutely +accurate, because it is made from the surface of the earth, and not from +the earth's centre, but the size of the earth is so insignificant in +comparison with the distance of the sun that this slight discrepancy +could be disregarded. + +The way in which Eratosthenes measured this angle was very simple. He +merely measured the angle of the shadow which his perpendicular gnomon +at Alexandria cast at mid-day on the day of the solstice, when, as +already noted, the sun was directly perpendicular at Syene. Now a glance +at the diagram will make it clear that the measurement of this angle +of the shadow is merely a convenient means of determining the precisely +equal opposite angle subtending an arc of an imaginary circle passing +through the sun; the are which, as already explained, corresponds with +the arc of the earth's surface represented by the distance between +Alexandria and Syene. He found this angle to represent 7 degrees 12', +or one-fiftieth of the circle. Five thousand stadia, then, represent +one-fiftieth of the earth's circumference; the entire circumference +being, therefore, 250,000 stadia. Unfortunately, we do not know which +one of the various measurements used in antiquity is represented by the +stadia of Eratosthenes. According to the researches of Lepsius, however, +the stadium in question represented 180 meters, and this would make the +earth, according to the measurement of Eratosthenes, about twenty-eight +thousand miles in circumference, an answer sufficiently exact to justify +the wonder which the experiment excited in antiquity, and the admiration +with which it has ever since been regarded. + +{illustration caption = DIAGRAM TO ILLUSTRATE ERATOSTHENES' MEASUREMENT +OF THE GLOBE + +FIG. 1. AF is a gnomon at Alexandria; SB a gnomon at Svene; IS and JK +represent the sun's rays. The angle actually measured by Eratosthenes +is KFA, as determined by the shadow cast by the gnomon AF. This angle is +equal to the opposite angle JFL, which measures the sun's distance from +the zenith; and which is also equal to the angle AES--to determine the +Size of which is the real object of the entire measurement. + +FIG. 2 shows the form of the gnomon actually employed in antiquity. The +hemisphere KA being marked with a scale, it is obvious that in actual +practice Eratosthenes required only to set his gnomon in the sunlight at +the proper moment, and read off the answer to his problem at a glance. +The simplicity of the method makes the result seem all the more +wonderful.} + +Of course it is the method, and not its details or its exact results, +that excites our interest. And beyond question the method was an +admirable one. Its result, however, could not have been absolutely +accurate, because, while correct in principle, its data were defective. +In point of fact Syene did not lie precisely on the same meridian as +Alexandria, neither did it lie exactly on the tropic. Here, then, +are two elements of inaccuracy. Moreover, it is doubtful whether +Eratosthenes made allowance, as he should have done, for the +semi-diameter of the sun in measuring the angle of the shadow. But +these are mere details, scarcely worthy of mention from our present +stand-point. What perhaps is deserving of more attention is the fact +that this epoch-making measurement of Eratosthenes may not have been the +first one to be made. A passage of Aristotle records that the size of +the earth was said to be 400,000 stadia. Some commentators have thought +that Aristotle merely referred to the area of the inhabited portion +of the earth and not to the circumference of the earth itself, but his +words seem doubtfully susceptible of this interpretation; and if he +meant, as his words seem to imply, that philosophers of his day had a +tolerably precise idea of the globe, we must assume that this idea was +based upon some sort of measurement. The recorded size, 400,000 stadia, +is a sufficient approximation to the truth to suggest something more +than a mere unsupported guess. Now, since Aristotle died more than fifty +years before Eratosthenes was born, his report as to the alleged size of +the earth certainly has a suggestiveness that cannot be overlooked; but +it arouses speculations without giving an inkling as to their solution. +If Eratosthenes had a precursor as an earth-measurer, no hint or rumor +has come down to us that would enable us to guess who that precursor may +have been. His personality is as deeply enveloped in the mists of the +past as are the personalities of the great prehistoric discoverers. For +the purpose of the historian, Eratosthenes must stand as the inventor +of the method with which his name is associated, and as the first man of +whom we can say with certainty that he measured the size of the earth. +Right worthily, then, had the Alexandrian philosopher won his proud +title of "surveyor of the world." + + +HIPPARCHUS, "THE LOVER OF TRUTH" + +Eratosthenes outlived most of his great contemporaries. He saw the +turning of that first and greatest century of Alexandrian science, the +third century before our era. He died in the year 196 B.C., having, +it is said, starved himself to death to escape the miseries of +blindness;--to the measurer of shadows, life without light seemed not +worth the living. Eratosthenes left no immediate successor. A generation +later, however, another great figure appeared in the astronomical world +in the person of Hipparchus, a man who, as a technical observer, had +perhaps no peer in the ancient world: one who set so high a value upon +accuracy of observation as to earn the title of "the lover of truth." +Hipparchus was born at Nicaea, in Bithynia, in the year 160 B.C. His +life, all too short for the interests of science, ended in the year 125 +B.C. The observations of the great astronomer were made chiefly, perhaps +entirely, at Rhodes. A misinterpretation of Ptolemy's writings led to +the idea that Hipparchus, performed his chief labors in Alexandria, but +it is now admitted that there is no evidence for this. Delambre doubted, +and most subsequent writers follow him here, whether Hipparchus ever so +much as visited Alexandria. In any event there seems to be no question +that Rhodes may claim the honor of being the chief site of his +activities. + +It was Hipparchus whose somewhat equivocal comment on the work of +Eratosthenes we have already noted. No counter-charge in kind could be +made against the critic himself; he was an astronomer pure and simple. +His gift was the gift of accurate observation rather than the gift +of imagination. No scientific progress is possible without scientific +guessing, but Hipparchus belonged to that class of observers with +whom hypothesis is held rigidly subservient to fact. It was not to be +expected that his mind would be attracted by the heliocentric theory of +Aristarchus. He used the facts and observations gathered by his great +predecessor of Samos, but he declined to accept his theories. For him +the world was central; his problem was to explain, if he could, the +irregularities of motion which sun, moon, and planets showed in +their seeming circuits about the earth. Hipparchus had the gnomon of +Eratosthenes--doubtless in a perfected form--to aid him, and he soon +proved himself a master in its use. For him, as we have said, accuracy +was everything; this was the one element that led to all his great +successes. + +Perhaps his greatest feat was to demonstrate the eccentricity of the +sun's seeming orbit. We of to-day, thanks to Keppler and his followers, +know that the earth and the other planetary bodies in their circuit +about the sun describe an ellipse and not a circle. But in the day of +Hipparchus, though the ellipse was recognized as a geometrical figure +(it had been described and named along with the parabola and hyperbola +by Apollonius of Perga, the pupil of Euclid), yet it would have been the +rankest heresy to suggest an elliptical course for any heavenly body. +A metaphysical theory, as propounded perhaps by the Pythagoreans but +ardently supported by Aristotle, declared that the circle is the perfect +figure, and pronounced it inconceivable that the motions of the spheres +should be other than circular. This thought dominated the mind of +Hipparchus, and so when his careful measurements led him to the +discovery that the northward and southward journeyings of the sun did +not divide the year into four equal parts, there was nothing open to him +but to either assume that the earth does not lie precisely at the centre +of the sun's circular orbit or to find some alternative hypothesis. + +In point of fact, the sun (reversing the point of view in accordance +with modern discoveries) does lie at one focus of the earth's elliptical +orbit, and therefore away from the physical centre of that orbit; in +other words, the observations of Hipparchus were absolutely accurate. He +was quite correct in finding that the sun spends more time on one side +of the equator than on the other. When, therefore, he estimated the +relative distance of the earth from the geometrical centre of the sun's +supposed circular orbit, and spoke of this as the measure of the sun's +eccentricity, he propounded a theory in which true data of observation +were curiously mingled with a positively inverted theory. That the +theory of Hipparchus was absolutely consistent with all the facts of +this particular observation is the best evidence that could be given +of the difficulties that stood in the way of a true explanation of the +mechanism of the heavens. + +But it is not merely the sun which was observed to vary in the speed +of its orbital progress; the moon and the planets also show curious +accelerations and retardations of motion. The moon in particular +received most careful attention from Hipparchus. Dominated by his +conception of the perfect spheres, he could find but one explanation of +the anomalous motions which he observed, and this was to assume that +the various heavenly bodies do not fly on in an unvarying arc in their +circuit about the earth, but describe minor circles as they go which can +be likened to nothing so tangibly as to a light attached to the rim of +a wagon-wheel in motion. If such an invisible wheel be imagined as +carrying the sun, for example, on its rim, while its invisible hub +follows unswervingly the circle of the sun's mean orbit (this wheel, be +it understood, lying in the plane of the orbit, not at right-angles to +it), then it must be obvious that while the hub remains always at the +same distance from the earth, the circling rim will carry the sun nearer +the earth, then farther away, and that while it is traversing that +portion of the are which brings it towards the earth, the actual forward +progress of the sun will be retarded notwithstanding the uniform motion +of the hub, just as it will be accelerated in the opposite arc. Now, if +we suppose our sun-bearing wheel to turn so slowly that the sun revolves +but once about its imaginary hub while the wheel itself is making the +entire circuit of the orbit, we shall have accounted for the observed +fact that the sun passes more quickly through one-half of the orbit than +through the other. Moreover, if we can visualize the process and imagine +the sun to have left a visible line of fire behind him throughout the +course, we shall see that in reality the two circular motions involved +have really resulted in producing an elliptical orbit. + +The idea is perhaps made clearer if we picture the actual progress of +the lantern attached to the rim of an ordinary cart-wheel. When the cart +is drawn forward the lantern is made to revolve in a circle as regards +the hub of the wheel, but since that hub is constantly going forward, +the actual path described by the lantern is not a circle at all but a +waving line. It is precisely the same with the imagined course of the +sun in its orbit, only that we view these lines just as we should view +the lantern on the wheel if we looked at it from directly above and not +from the side. The proof that the sun is describing this waving line, +and therefore must be considered as attached to an imaginary wheel, is +furnished, as it seemed to Hipparchus, by the observed fact of the sun's +varying speed. + +That is one way of looking at the matter. It is an hypothesis that +explains the observed facts--after a fashion, and indeed a very +remarkable fashion. The idea of such an explanation did not originate +with Hipparchus. The germs of the thought were as old as the Pythagorean +doctrine that the earth revolves about a centre that we cannot see. +Eudoxus gave the conception greater tangibility, and may be considered +as the father of this doctrine of wheels--epicycles, as they came to +be called. Two centuries before the time of Hipparchus he conceived a +doctrine of spheres which Aristotle found most interesting, and which +served to explain, along the lines we have just followed, the observed +motions of the heavenly bodies. Calippus, the reformer of the calendar, +is said to have carried an account of this theory to Aristotle. As new +irregularities of motion of the sun, moon, and planetary bodies were +pointed out, new epicycles were invented. There is no limit to the +number of imaginary circles that may be inscribed about an imaginary +centre, and if we conceive each one of these circles to have a proper +motion of its own, and each one to carry the sun in the line of that +motion, except as it is diverted by the other motions--if we can +visualize this complex mingling of wheels--we shall certainly be able to +imagine the heavenly body which lies at the juncture of all the rims, +as being carried forward in as erratic and wobbly a manner as could be +desired. In other words, the theory of epicycles will account for all +the facts of the observed motions of all the heavenly bodies, but in +so doing it fills the universe with a most bewildering network of +intersecting circles. Even in the time of Calippus fifty-five of these +spheres were computed. + +We may well believe that the clear-seeing Aristarchus would look +askance at such a complex system of imaginary machinery. But Hipparchus, +pre-eminently an observer rather than a theorizer, seems to have been +content to accept the theory of epicycles as he found it, though his +studies added to its complexities; and Hipparchus was the dominant +scientific personality of his century. What he believed became as a law +to his immediate successors. His tenets were accepted as final by +their great popularizer, Ptolemy, three centuries later; and so the +heliocentric theory of Aristarchus passed under a cloud almost at the +hour of its dawning, there to remain obscured and forgotten for the +long lapse of centuries. A thousand pities that the greatest observing +astronomer of antiquity could not, like one of his great precursors, +have approached astronomy from the stand-point of geography and poetry. +Had he done so, perhaps he might have reflected, like Aristarchus +before him, that it seems absurd for our earth to hold the giant sun +in thraldom; then perhaps his imagination would have reached out to the +heliocentric doctrine, and the cobweb hypothesis of epicycles, with that +yet more intangible figment of the perfect circle, might have been wiped +away. + +But it was not to be. With Aristarchus the scientific imagination had +reached its highest flight; but with Hipparchus it was beginning to +settle back into regions of foggier atmosphere and narrower horizons. +For what, after all, does it matter that Hipparchus should go on to +measure the precise length of the year and the apparent size of the +moon's disk; that he should make a chart of the heavens showing the +place of 1080 stars; even that he should discover the precession of +the equinox;--what, after all, is the significance of these details as +against the all-essential fact that the greatest scientific authority of +his century--the one truly heroic scientific figure of his epoch--should +have lent all the forces of his commanding influence to the old, false +theory of cosmology, when the true theory had been propounded and when +he, perhaps, was the only man in the world who might have substantiated +and vitalized that theory? It is easy to overestimate the influence of +any single man, and, contrariwise, to underestimate the power of the +Zeitgeist. But when we reflect that the doctrines of Hipparchus, +as promulgated by Ptolemy, became, as it were, the last word of +astronomical science for both the Eastern and Western worlds, and so +continued after a thousand years, it is perhaps not too much to say +that Hipparchus, "the lover of truth," missed one of the greatest +opportunities for the promulgation of truth ever vouchsafed to a devotee +of pure science. + +But all this, of course, detracts nothing from the merits of Hipparchus +as an observing astronomer. A few words more must be said as to his +specific discoveries in this field. According to his measurement, the +tropic year consists of 365 days, 5 hours, and 49 minutes, varying thus +only 12 seconds from the true year, as the modern astronomer estimates +it. Yet more remarkable, because of the greater difficulties involved, +was Hipparchus's attempt to measure the actual distance of the moon. +Aristarchus had made a similar attempt before him. Hipparchus based +his computations on studies of the moon in eclipse, and he reached the +conclusion that the distance of the moon is equal to 59 radii of the +earth (in reality it is 60.27 radii). Here, then, was the measure of the +base-line of that famous triangle with which Aristarchus had measured +the distance of the sun. Hipparchus must have known of that measurement, +since he quotes the work of Aristarchus in other fields. Had he now but +repeated the experiment of Aristarchus, with his perfected instruments +and his perhaps greater observational skill, he was in position to +compute the actual distance of the sun in terms not merely of the moon's +distance but of the earth's radius. And now there was the experiment +of Eratosthenes to give the length of that radius in precise terms. In +other words, Hipparchus might have measured the distance of the sun in +stadia. But if he had made the attempt--and, indeed, it is more than +likely that he did so--the elements of error in his measurements would +still have kept him wide of the true figures. + +The chief studies of Hipparchus were directed, as we have seen, towards +the sun and the moon, but a phenomenon that occurred in the year 134 +B.C. led him for a time to give more particular attention to the fixed +stars. The phenomenon in question was the sudden outburst of a new +star; a phenomenon which has been repeated now and again, but which +is sufficiently rare and sufficiently mysterious to have excited the +unusual attention of astronomers in all generations. Modern science +offers an explanation of the phenomenon, as we shall see in due course. +We do not know that Hipparchus attempted to explain it, but he was led +to make a chart of the heavens, probably with the idea of guiding future +observers in the observation of new stars. Here again Hipparchus was not +altogether an innovator, since a chart showing the brightest stars had +been made by Eratosthenes; but the new charts were much elaborated. + +The studies of Hipparchus led him to observe the stars chiefly with +reference to the meridian rather than with reference to their rising, +as had hitherto been the custom. In making these studies of the relative +position of the stars, Hipparchus was led to compare his observations +with those of the Babylonians, which, it was said, Alexander had caused +to be transmitted to Greece. He made use also of the observations +of Aristarchus and others of his Greek precursors. The result of his +comparisons proved that the sphere of the fixed stars had apparently +shifted its position in reference to the plane of the sun's orbit--that +is to say, the plane of the ecliptic no longer seemed to cut the sphere +of the fixed stars at precisely the point where the two coincided in +former centuries. The plane of the ecliptic must therefore be conceived +as slowly revolving in such a way as gradually to circumnavigate the +heavens. This important phenomenon is described as the precession of the +equinoxes. + +It is much in question whether this phenomenon was not known to the +ancient Egyptian astronomers; but in any event, Hipparchus is to be +credited with demonstrating the fact and making it known to the +Western world. A further service was rendered theoretical astronomy by +Hipparchus through his invention of the planosphere, an instrument for +the representation of the mechanism of the heavens. His computations +of the properties of the spheres led him also to what was virtually a +discovery of the method of trigonometry, giving him, therefore, a high +position in the field of mathematics. All in all, then, Hipparchus is a +most heroic figure. He may well be considered the greatest star-gazer of +antiquity, though he cannot, without injustice to his great precursors, +be allowed the title which is sometimes given him of "father of +systematic astronomy." + + +CTESIBIUS AND HERO: MAGICIANS OF ALEXANDRIA + +Just about the time when Hipparchus was working out at Rhodes his +puzzles of celestial mechanics, there was a man in Alexandria who was +exercising a strangely inventive genius over mechanical problems of +another sort; a man who, following the example set by Archimedes a +century before, was studying the problems of matter and putting his +studies to practical application through the invention of weird devices. +The man's name was Ctesibius. We know scarcely more of him than that he +lived in Alexandria, probably in the first half of the second century +B.C. His antecedents, the place and exact time of his birth and death, +are quite unknown. Neither are we quite certain as to the precise range +of his studies or the exact number of his discoveries. It appears that +he had a pupil named Hero, whose personality, unfortunately, is scarcely +less obscure than that of his master, but who wrote a book through which +the record of the master's inventions was preserved to posterity. Hero, +indeed, wrote several books, though only one of them has been preserved. +The ones that are lost bear the following suggestive titles: On +the Construction of Slings; On the Construction of Missiles; On the +Automaton; On the Method of Lifting Heavy Bodies; On the Dioptric +or Spying-tube. The work that remains is called Pneumatics, and so +interesting a work it is as to make us doubly regret the loss of its +companion volumes. Had these other books been preserved we should +doubtless have a clearer insight than is now possible into some at +least of the mechanical problems that exercised the minds of the ancient +philosophers. The book that remains is chiefly concerned, as its name +implies, with the study of gases, or, rather, with the study of a single +gas, this being, of course, the air. But it tells us also of certain +studies in the dynamics of water that are most interesting, and for the +historian of science most important. + +Unfortunately, the pupil of Ctesibius, whatever his ingenuity, was a +man with a deficient sense of the ethics of science. He tells us in +his preface that the object of his book is to record some ingenious +discoveries of others, together with additional discoveries of his own, +but nowhere in the book itself does he give us the, slightest clew as to +where the line is drawn between the old and the new. Once, in discussing +the weight of water, he mentions the law of Archimedes regarding a +floating body, but this is the only case in which a scientific principle +is traced to its source or in which credit is given to any one for a +discovery. This is the more to be regretted because Hero has discussed +at some length the theories involved in the treatment of his subject. +This reticence on the part of Hero, combined with the fact that such +somewhat later writers as Pliny and Vitruvius do not mention Hero's +name, while they frequently mention the name of his master, Ctesibius, +has led modern critics to a somewhat sceptical attitude regarding the +position of Hero as an actual discoverer. + +The man who would coolly appropriate some discoveries of others under +cloak of a mere prefatorial reference was perhaps an expounder rather +than an innovator, and had, it is shrewdly suspected, not much of his +own to offer. Meanwhile, it is tolerably certain that Ctesibius was the +discoverer of the principle of the siphon, of the forcing-pump, and of a +pneumatic organ. An examination of Hero's book will show that these are +really the chief principles involved in most of the various interesting +mechanisms which he describes. We are constrained, then, to believe that +the inventive genius who was really responsible for the mechanisms we +are about to describe was Ctesibius, the master. Yet we owe a debt of +gratitude to Hero, the pupil, for having given wider vogue to these +discoveries, and in particular for the discussion of the principles of +hydrostatics and pneumatics contained in the introduction to his +book. This discussion furnishes us almost our only knowledge as to the +progress of Greek philosophers in the field of mechanics since the time +of Archimedes. + +The main purpose of Hero in his preliminary thesis has to do with the +nature of matter, and recalls, therefore, the studies of Anaxagoras and +Democritus. Hero, however, approaches his subject from a purely material +or practical stand-point. He is an explicit champion of what we nowadays +call the molecular theory of matter. "Every body," he tells us, "is +composed of minute particles, between which are empty spaces less than +these particles of the body. It is, therefore, erroneous to say that +there is no vacuum except by the application of force, and that every +space is full either of air or water or some other substance. But in +proportion as any one of these particles recedes, some other follows +it and fills the vacant space; therefore there is no continuous vacuum, +except by the application of some force (like suction)--that is to +say, an absolute vacuum is never found, except as it is produced +artificially." Hero brings forward some thoroughly convincing proofs of +the thesis he is maintaining. "If there were no void places between the +particles of water," he says, "the rays of light could not penetrate the +water; moreover, another liquid, such as wine, could not spread itself +through the water, as it is observed to do, were the particles of water +absolutely continuous." The latter illustration is one the validity of +which appeals as forcibly to the physicists of to-day as it did to +Hero. The same is true of the argument drawn from the compressibility of +gases. Hero has evidently made a careful study of this subject. He +knows that an inverted tube full of air may be immersed in water without +becoming wet on the inside, proving that air is a physical substance; +but he knows also that this same air may be caused to expand to a much +greater bulk by the application of heat, or may, on the other hand, +be condensed by pressure, in which case, as he is well aware, the air +exerts force in the attempt to regain its normal bulk. But, he argues, +surely we are not to believe that the particles of air expand to +fill all the space when the bulk of air as a whole expands under the +influence of heat; nor can we conceive that the particles of normal air +are in actual contact, else we should not be able to compress the air. +Hence his conclusion, which, as we have seen, he makes general in its +application to all matter, that there are spaces, or, as he calls them, +vacua, between the particles that go to make up all substances, whether +liquid, solid, or gaseous. + +Here, clearly enough, was the idea of the "atomic" nature of matter +accepted as a fundamental notion. The argumentative attitude assumed by +Hero shows that the doctrine could not be expected to go unchallenged. +But, on the other hand, there is nothing in his phrasing to suggest an +intention to claim originality for any phase of the doctrine. We may +infer that in the three hundred years that had elapsed since the time +of Anaxagoras, that philosopher's idea of the molecular nature of matter +had gained fairly wide currency. As to the expansive power of gas, +which Hero describes at some length without giving us a clew to his +authorities, we may assume that Ctesibius was an original worker, yet +the general facts involved were doubtless much older than his day. Hero, +for example, tells us of the cupping-glass used by physicians, which +he says is made into a vacuum by burning up the air in it; but this +apparatus had probably been long in use, and Hero mentions it not in +order to describe the ordinary cupping-glass which is referred to, but +a modification of it. He refers to the old form as if it were something +familiar to all. + +Again, we know that Empedocles studied the pressure of the air in the +fifth century B.C., and discovered that it would support a column of +water in a closed tube, so this phase of the subject is not new. +But there is no hint anywhere before this work of Hero of a clear +understanding that the expansive properties of the air when compressed, +or when heated, may be made available as a motor power. Hero, however, +has the clearest notions on the subject and puts them to the practical +test of experiment. Thus he constructs numerous mechanisms in which the +expansive power of air under pressure is made to do work, and others in +which the same end is accomplished through the expansive power of +heated air. For example, the doors of a temple are made to swing open +automatically when a fire is lighted on a distant altar, closing again +when the fire dies out--effects which must have filled the minds of +the pious observers with bewilderment and wonder, serving a most useful +purpose for the priests, who alone, we may assume, were in the secret. +There were two methods by which this apparatus was worked. In one the +heated air pressed on the water in a close retort connected with the +altar, forcing water out of the retort into a bucket, which by its +weight applied a force through pulleys and ropes that turned the +standards on which the temple doors revolved. When the fire died down +the air contracted, the water was siphoned back from the bucket, which, +being thus lightened, let the doors close again through the action of +an ordinary weight. The other method was a slight modification, in which +the retort of water was dispensed with and a leather sack like a large +football substitued. The ropes and pulleys were connected with this +sack, which exerted a pull when the hot air expanded, and which +collapsed and thus relaxed its strain when the air cooled. A glance at +the illustrations taken from Hero's book will make the details clear. + +Other mechanisms utilized a somewhat different combination of weights, +pulleys, and siphons, operated by the expansive power of air, unheated +but under pressure, such pressure being applied with a force-pump, or by +the weight of water running into a closed receptacle. One such mechanism +gives us a constant jet of water or perpetual fountain. Another curious +application of the principle furnishes us with an elaborate toy, +consisting of a group of birds which alternately whistle or are silent, +while an owl seated on a neighboring perch turns towards the birds when +their song begins and away from them when it ends. The "singing" of the +birds, it must be explained, is produced by the expulsion of air through +tiny tubes passing up through their throats from a tank below. The owl +is made to turn by a mechanism similar to that which manipulates the +temple doors. The pressure is supplied merely by a stream of running +water, and the periodical silence of the birds is due to the fact that +this pressure is relieved through the automatic siphoning off of the +water when it reaches a certain height. The action of the siphon, it may +be added, is correctly explained by Hero as due to the greater weight of +the water in the longer arm of the bent tube. As before mentioned, the +siphon is repeatedly used in these mechanisms of Hero. The diagram will +make clear the exact application of it in the present most ingenious +mechanism. We may add that the principle of the whistle was a favorite +one of Hero. By the aid of a similar mechanism he brought about the +blowing of trumpets when the temple doors were opened, a phenomenon +which must greatly have enhanced the mystification. It is possible that +this principle was utilized also in connection with statues to produce +seemingly supernatural effects. This may be the explanation of the +tradition of the speaking statue in the temple of Ammon at Thebes. + +{illustration caption = DEVICE FOR CAUSING THE DOORS OF THE TEMPLE TO +OPEN WHEN THE FIRE ON THE ALTAR IS LIGHTED (Air heated in the altar F +drives water from the closed receptacle H through the tube KL into the +bucket M, which descends through gravity, thus opening the doors. When +the altar cools, the air contracts, the water is sucked from the bucket, +and the weight and pulley close the doors.)} + +{illustration caption = THE STEAM-ENGINE OF HERO (The steam generated in +the receptacle AB passes through the tube EF into the globe, and escapes +through the bent tubes H and K, causing the globe to rotate on the axis +LG.)} + + +The utilization of the properties of compressed air was not confined, +however, exclusively to mere toys, or to produce miraculous effects. The +same principle was applied to a practical fire-engine, worked by levers +and force-pumps; an apparatus, in short, altogether similar to that +still in use in rural districts. A slightly different application of the +motive power of expanding air is furnished in a very curious toy called +"the dancing figures." In this, air heated in a retort like a miniature +altar is allowed to escape through the sides of two pairs of revolving +arms precisely like those of the ordinary revolving fountain with which +we are accustomed to water our lawns, the revolving arms being attached +to a plane on which several pairs of statuettes representing dancers +are placed, An even more interesting application of this principle of +setting a wheel in motion is furnished in a mechanism which must be +considered the earliest of steam-engines. Here, as the name implies, the +gas supplying the motive power is actually steam. The apparatus made +to revolve is a globe connected with the steam-retort by a tube which +serves as one of its axes, the steam escaping from the globe through two +bent tubes placed at either end of an equatorial diameter. It does +not appear that Hero had any thought of making practical use of this +steam-engine. It was merely a curious toy--nothing more. Yet had not the +age that succeeded that of Hero been one in which inventive genius +was dormant, some one must soon have hit upon the idea that this +steam-engine might be improved and made to serve a useful purpose. As +the case stands, however, there was no advance made upon the steam motor +of Hero for almost two thousand years. And, indeed, when the practical +application of steam was made, towards the close of the eighteenth +century, it was made probably quite without reference to the experiment +of Hero, though knowledge of his toy may perhaps have given a clew to +Watt or his predecessors. + + +{illustration caption = THE SLOT-MACHINE OF HERO (The coin introduced at +A falls on the lever R, and by its weight opens the valve S, permitting +the liquid to escape through the invisible tube LM. As the lever tips, +the coin slides off and the valve closes. The liquid in tank must of +course be kept above F.)} + +In recent times there has been a tendency to give to this steam-engine +of Hero something more than full meed of appreciation. To be sure, it +marked a most important principle in the conception that steam might +be used as a motive power, but, except in the demonstration of this +principle, the mechanism of Hero was much too primitive to be of any +importance. But there is one mechanism described by Hero which was a +most explicit anticipation of a device, which presumably soon went out +of use, and which was not reinvented until towards the close of the +nineteenth century. This was a device which has become familiar in +recent times as the penny-in-the-slot machine. When towards the close of +the nineteenth century some inventive craftsman hit upon the idea of an +automatic machine to supply candy, a box of cigarettes, or a whiff +of perfumery, he may or may not have borrowed his idea from the +slot-machine of Hero; but in any event, instead of being an innovator he +was really two thousand years behind the times, for the slot-machine of +Hero is the precise prototype of these modern ones. + +The particular function which the mechanism of Hero was destined to +fulfil was the distribution of a jet of water, presumably used +for sacramental purposes, which was given out automatically when a +five-drachma coin was dropped into the slot at the top of the machine. +The internal mechanism of the machine was simple enough, consisting +merely of a lever operating a valve which was opened by the weight of +the coin dropping on the little shelf at the end of the lever, and which +closed again when the coin slid off the shelf. The illustration will +show how simple this mechanism was. Yet to the worshippers, who probably +had entered the temple through doors miraculously opened, and who now +witnessed this seemingly intelligent response of a machine, the result +must have seemed mystifying enough; and, indeed, for us also, when we +consider how relatively crude was the mechanical knowledge of the time, +this must seem nothing less than marvellous. As in imagination we walk +up to the sacred tank, drop our drachma in the slot, and hold our hand +for the spurt of holy-water, can we realize that this is the land of the +Pharaohs, not England or America; that the kingdom of the Ptolemies is +still at its height; that the republic of Rome is mistress of the world; +that all Europe north of the Alps is inhabited solely by barbarians; +that Cleopatra and Julius Caesar are yet unborn; that the Christian era +has not yet begun? Truly, it seems as if there could be no new thing +under the sun. + + + + +X. SCIENCE OF THE ROMAN PERIOD + +We have seen that the third century B.C. was a time when Alexandrian +science was at its height, but that the second century produced also in +Hipparchus at least one investigator of the very first rank; though, to +be sure, Hipparchus can be called an Alexandrian only by courtesy. +In the ensuing generations the Greek capital at the mouth of the +Nile continued to hold its place as the centre of scientific and +philosophical thought. The kingdom of the Ptolemies still flourished +with at least the outward appearances of its old-time glory, and a +company of grammarians and commentators of no small merit could always +be found in the service of the famous museum and library; but the whole +aspect of world-history was rapidly changing. Greece, after her brief +day of political supremacy, was sinking rapidly into desuetude, and +the hard-headed Roman in the West was making himself master everywhere. +While Hipparchus of Rhodes was in his prime, Corinth, the last +stronghold of the main-land of Greece, had fallen before the prowess +of the Roman, and the kingdom of the Ptolemies, though still nominally +free, had begun to come within the sphere of Roman influence. + +Just what share these political changes had in changing the aspect of +Greek thought is a question regarding which difference of opinion might +easily prevail; but there can be no question that, for one reason or +another, the Alexandrian school as a creative centre went into a rapid +decline at about the time of the Roman rise to world-power. There are +some distinguished names, but, as a general rule, the spirit of the +times is reminiscent rather than creative; the workers tend to collate +the researches of their predecessors rather than to make new and +original researches for themselves. Eratosthenes, the inventive +world-measurer, was succeeded by Strabo, the industrious collator of +facts; Aristarchus and Hipparchus, the originators of new astronomical +methods, were succeeded by Ptolemy, the perfecter of their methods and +the systematizer of their knowledge. Meanwhile, in the West, Rome +never became a true culture-centre. The great genius of the Roman was +political; the Augustan Age produced a few great historians and poets, +but not a single great philosopher or creative devotee of science. +Cicero, Lucian, Seneca, Marcus Aurelius, give us at best a reflection +of Greek philosophy. Pliny, the one world-famous name in the scientific +annals of Rome, can lay claim to no higher credit than that of a +marvellously industrious collector of facts--the compiler of an +encyclopaedia which contains not one creative touch. + +All in all, then, this epoch of Roman domination is one that need detain +the historian of science but a brief moment. With the culmination of +Greek effort in the so-called Hellenistic period we have seen ancient +science at its climax. The Roman period is but a time of transition, +marking, as it were, a plateau on the slope between those earlier +heights and the deep, dark valleys of the Middle Ages. Yet we cannot +quite disregard the efforts of such workers as those we have just named. +Let us take a more specific glance at their accomplishments. + + +STRABO THE GEOGRAPHER + +The earliest of these workers in point of time is Strabo. This most +famous of ancient geographers was born in Amasia, Pontus, about 63 B.C., +and lived to the year 24 A.D., living, therefore, in the age of Caesar +and Augustus, during which the final transformation in the political +position of the kingdom of Egypt was effected. The name of Strabo in a +modified form has become popularized through a curious circumstance. +The geographer, it appears, was afflicted with a peculiar squint of the +eyes, hence the name strabismus, which the modern oculist applies to +that particular infirmity. + +Fortunately, the great geographer has not been forced to depend upon +hearsay evidence for recognition. His comprehensive work on geography +has been preserved in its entirety, being one of the few expansive +classical writings of which this is true. The other writings of Strabo, +however, including certain histories of which reports have come down to +us, are entirely lost. The geography is in many ways a remarkable book. +It is not, however, a work in which any important new principles are +involved. Rather is it typical of its age in that it is an elaborate +compilation and a critical review of the labors of Strabo's +predecessors. Doubtless it contains a vast deal of new information as +to the details of geography--precise areas and distance, questions +of geographical locations as to latitude and zones, and the like. +But however important these details may have been from a contemporary +stand-point, they, of course, can have nothing more than historical +interest to posterity. The value of the work from our present +stand-point is chiefly due to the criticisms which Strabo passes +upon his forerunners, and to the incidental historical and scientific +references with which his work abounds. Being written in this closing +period of ancient progress, and summarizing, as it does, in full detail +the geographical knowledge of the time, it serves as an important +guide-mark for the student of the progress of scientific thought. We +cannot do better than briefly to follow Strabo in his estimates and +criticisms of the work of his predecessors, taking note thus of the +point of view from which he himself looked out upon the world. We shall +thus gain a clear idea as to the state of scientific geography towards +the close of the classical epoch. + +"If the scientific investigation of any subject be the proper avocation +of the philosopher," says Strabo, "geography, the science of which we +propose to treat, is certainly entitled to a high place; and this is +evident from many considerations. They who first undertook to handle +the matter were distinguished men. Homer, Anaximander the Milesian, +and Hecaeus (his fellow-citizen according to Eratosthenes), Democritus, +Eudoxus, Dicaearchus, and Ephorus, with many others, and after these, +Eratosthenes, Polybius, and Posidonius, all of them philosophers. Nor +is the great learning through which alone this subject can be approached +possessed by any but a person acquainted with both human and divine +things, and these attainments constitute what is called philosophy. In +addition to its vast importance in regard to social life and the art of +government, geography unfolds to us a celestial phenomena, acquaints us +with the occupants of the land and ocean, and the vegetation, fruits, +and peculiarities of the various quarters of the earth, a knowledge of +which marks him who cultivates it as a man earnest in the great problem +of life and happiness." + +Strabo goes on to say that in common with other critics, including +Hipparchus, he regards Homer as the first great geographer. He has much +to say on the geographical knowledge of the bard, but this need not +detain us. We are chiefly concerned with his comment upon his more +recent predecessors, beginning with Eratosthenes. The constant reference +to this worker shows the important position which he held. Strabo +appears neither as detractor nor as partisan, but as one who earnestly +desires the truth. Sometimes he seems captious in his criticisms +regarding some detail, nor is he always correct in his emendations +of the labors of others; but, on the whole, his work is marked by an +evident attempt at fairness. In reading his book, however, one is forced +to the conclusion that Strabo is an investigator of details, not an +original thinker. He seems more concerned with precise measurements than +with questionings as to the open problems of his science. Whatever +he accepts, then, may be taken as virtually the stock doctrine of the +period. + +"As the size of the earth," he says, "has been demonstrated by other +writers, we shall here take for granted and receive as accurate what +they have advanced. We shall also assume that the earth is spheroidal, +that its surface is likewise spheroidal and, above all, that bodies +have a tendency towards its centre, which latter point is clear to +the perception of the most average understanding. However, we may show +summarily that the earth is spheroidal, from the consideration that +all things, however distant, tend to its centre, and that every body is +attracted towards its centre by gravity. This is more distinctly proved +from observations of the sea and sky, for here the evidence of the +senses and common observation is alone requisite. The convexity of the +sea is a further proof of this to those who have sailed, for they cannot +perceive lights at a distance when placed at the same level as their +eyes, and if raised on high they at once become perceptible to vision +though at the same time farther removed. So when the eye is raised it +sees what before was utterly imperceptible. Homer speaks of this when he +says: + + + "'Lifted up on the vast wave he quickly beheld afar.' + +"Sailors as they approach their destination behold the shore continually +raising itself to their view, and objects which had at first seemed low +begin to lift themselves. Our gnomons, also, are, among other things, +evidence of the revolution of the heavenly bodies, and common-sense +at once shows us that if the depth of the earth were infinite such a +revolution could not take place."(1) + +Elsewhere Strabo criticises Eratosthenes for having entered into a long +discussion as to the form of the earth. This matter, Strabo thinks, +"should have been disposed of in the compass of a few words." Obviously +this doctrine of the globe's sphericity had, in the course of 600 years, +become so firmly established among the Greek thinkers as to seem almost +axiomatic. We shall see later on how the Western world made a curious +recession from this seemingly secure position under stimulus of an +Oriental misconception. As to the size of the globe, Strabo is disposed +to accept without particular comment the measurements of Eratosthenes. +He speaks, however, of "more recent measurements," referring in +particular to that adopted by Posidonius, according to which the +circumference is only about one hundred and eighty thousand stadia. +Posidonius, we may note in passing, was a contemporary and friend +of Cicero, and hence lived shortly before the time of Strabo. His +measurement of the earth was based on observations of a star which +barely rose above the southern horizon at Rhodes as compared with the +height of the same star when observed at Alexandria. This measurement +of Posidonius, together with the even more famous measurement of +Eratosthenes, appears to have been practically the sole guide as to +the size of the earth throughout the later periods of antiquity, and, +indeed, until the later Middle Ages. + +As becomes a writer who is primarily geographer and historian rather +than astronomer, Strabo shows a much keener interest in the habitable +portions of the globe than in the globe as a whole. He assures us that +this habitable portion of the earth is a great island, "since wherever +men have approached the termination of the land, the sea, which we +designate ocean, has been met with, and reason assures us of the +similarity of this place which our senses have not been tempted to +survey." He points out that whereas sailors have not circumnavigated the +globe, that they had not been prevented from doing so by any continent, +and it seems to him altogether unlikely that the Atlantic Ocean is +divided into two seas by narrow isthmuses so placed as to prevent +circumnavigation. "How much more probable that it is confluent and +uninterrupted. This theory," he adds, "goes better with the ebb and flow +of the ocean. Moreover (and here his reasoning becomes more fanciful), +the greater the amount of moisture surrounding the earth, the easier +would the heavenly bodies be supplied with vapor from thence." Yet he is +disposed to believe, following Plato, that the tradition "concerning +the island of Atlantos might be received as something more than idle +fiction, it having been related by Solon, on the authority of the +Egyptian priests, that this island, almost as large as a continent, was +formerly in existence although now it had disappeared."(2) + +In a word, then, Strabo entertains no doubt whatever that it would +be possible to sail around the globe from Spain to India. Indeed, so +matter-of-fact an inference was this that the feat of Columbus would +have seemed less surprising in the first century of our era than it did +when actually performed in the fifteenth century. The terrors of the +great ocean held the mariner back, rather than any doubt as to where he +would arrive at the end of the voyage. + +Coupled with the idea that the habitable portion of the earth is an +island, there was linked a tolerably definite notion as to the shape +of this island. This shape Strabo likens to a military cloak. The +comparison does not seem peculiarly apt when we are told presently that +the length of the habitable earth is more than twice its breadth. This +idea, Strabo assures us, accords with the most accurate observations +"both ancient and modern." These observations seemed to show that it is +not possible to live in the region close to the equator, and that, on +the other hand, the cold temperature sharply limits the habitability of +the globe towards the north. All the civilization of antiquity clustered +about the Mediterranean, or extended off towards the east at about the +same latitude. Hence geographers came to think of the habitable globe as +having the somewhat lenticular shape which a crude map of these regions +suggests. We have already had occasion to see that at an earlier day +Anaxagoras was perhaps influenced in his conception of the shape of the +earth by this idea, and the constant references of Strabo impress upon +us the thought that this long, relatively narrow area of the earth's +surface is the only one which can be conceived of as habitable. + +Strabo had much to tell us concerning zones, which, following +Posidonius, he believes to have been first described by Parmenides. We +may note, however, that other traditions assert that both Thales +and Pythagoras had divided the earth into zones. The number of zones +accepted by Strabo is five, and he criticises Polybius for making +the number six. The five zones accepted by Strabo are as follows: the +uninhabitable torrid zone lying in the region of the equator; a zone +on either side of this extending to the tropic; and then the temperate +zones extending in either direction from the tropic to the arctic +regions. There seems to have been a good deal of dispute among the +scholars of the time as to the exact arrangement of these zones, but the +general idea that the north-temperate zone is the part of the earth +with which the geographer deals seemed clearly established. That the +south-temperate zone would also present a habitable area is an idea that +is sometimes suggested, though seldom or never distinctly expressed. It +is probable that different opinions were held as to this, and no direct +evidence being available, a cautiously scientific geographer like Strabo +would naturally avoid the expression of an opinion regarding it. Indeed, +his own words leave us somewhat in doubt as to the precise character of +his notion regarding the zones. Perhaps we shall do best to quote them: + +"Let the earth be supposed to consist of five zones. (1) The equatorial +circle described around it. (2) Another parallel to this, and defining +the frigid zone of the northern hemisphere. (3) A circle passing through +the poles and cutting the two preceding circles at right-angles. The +northern hemisphere contains two quarters of the earth, which are +bounded by the equator and circle passing through the poles. Each of +these quarters should be supposed to contain a four-sided district, +its northern side being of one-half of the parallel next the pole, its +southern by the half of the equator, and its remaining sides by two +segments of the circle drawn through the poles, opposite to each +other, and equal in length. In one of these (which of them is of no +consequence) the earth which we inhabit is situated, surrounded by a sea +and similar to an island. This, as we said before, is evident both to +our senses and to our reason. But let any one doubt this, it makes no +difference so far as geography is concerned whether you believe the +portion of the earth which we inhabit to be an island or only admit what +we know from experience--namely, that whether you start from the east +or the west you may sail all around it. Certain intermediate spaces may +have been left (unexplored), but these are as likely to be occupied by +sea as uninhabited land. The object of the geographer is to describe +known countries. Those which are unknown he passes over equally with +those beyond the limits of the inhabited earth. It will, therefore, +be sufficient for describing the contour of the island we have been +speaking of, if we join by a right line the outmost points which, up +to this time, have been explored by voyagers along the coast on either +side."(3) + +We may pass over the specific criticisms of Strabo upon various +explorations that seem to have been of great interest to his +contemporaries, including an alleged trip of one Eudoxus out into +the Atlantic, and the journeyings of Pytheas in the far north. It is +Pytheas, we may add, who was cited by Hipparchus as having made the +mistaken observation that the length of the shadow of the gnomon is the +same at Marseilles and Byzantium, hence that these two places are on the +same parallel. Modern commentators have defended Pytheas as regards this +observation, claiming that it was Hipparchus and not Pytheas who made +the second observation from which the faulty induction was drawn. The +point is of no great significance, however, except as showing that a +correct method of determining the problems of latitude had thus early +been suggested. That faulty observations and faulty application of the +correct principle should have been made is not surprising. Neither need +we concern ourselves with the details as to the geographical distances, +which Strabo found so worthy of criticism and controversy. But in +leaving the great geographer we may emphasize his point of view and that +of his contemporaries by quoting three fundamental principles which +he reiterates as being among the "facts established by natural +philosophers." He tells us that "(1) The earth and heavens are +spheroidal. (2) The tendency of all bodies having weight is towards +a centre. (3) Further, the earth being spheroidal and having the same +centre as the heavens, is motionless, as well as the axis that passes +through both it and the heavens. The heavens turn round both the earth +and its axis, from east to west. The fixed stars turn round with it at +the same rate as the whole. These fixed stars follow in their course +parallel circles, the principal of which are the equator, two tropics, +and the arctic circles; while the planets, the sun, and the moon +describe certain circles comprehended within the zodiac."(4) + +Here, then, is a curious mingling of truth and error. The Pythagorean +doctrine that the earth is round had become a commonplace, but it would +appear that the theory of Aristarchus, according to which the earth is +in motion, has been almost absolutely forgotten. Strabo does not so much +as refer to it; neither, as we shall see, is it treated with greater +respect by the other writers of the period. + + +TWO FAMOUS EXPOSITORS--PLINY AND PTOLEMY + +While Strabo was pursuing his geographical studies at Alexandria, a +young man came to Rome who was destined to make his name more widely +known in scientific annals than that of any other Latin writer of +antiquity. This man was Plinius Secundus, who, to distinguish him from +his nephew, a famous writer in another field, is usually spoken of as +Pliny the Elder. There is a famous story to the effect that the great +Roman historian Livy on one occasion addressed a casual associate in the +amphitheatre at Rome, and on learning that the stranger hailed from the +outlying Spanish province of the empire, remarked to him, "Yet you +have doubtless heard of my writings even there." "Then," replied the +stranger, "you must be either Livy or Pliny." + +The anecdote illustrates the wide fame which the Roman naturalist +achieved in his own day. And the records of the Middle Ages show that +this popularity did not abate in succeeding times. Indeed, the Natural +History of Pliny is one of the comparatively few bulky writings of +antiquity that the efforts of copyists have preserved to us almost +entire. It is, indeed, a remarkable work and eminently typical of its +time; but its author was an industrious compiler, not a creative genius. +As a monument of industry it has seldom been equalled, and in this +regard it seems the more remarkable inasmuch as Pliny was a practical +man of affairs who occupied most of his life as a soldier fighting the +battles of the empire. He compiled his book in the leisure hours stolen +from sleep, often writing by the light of the camp-fire. Yet he cites +or quotes from about four thousand works, most of which are known to +us only by his references. Doubtless Pliny added much through his own +observations. We know how keen was his desire to investigate, since he +lost his life through attempting to approach the crater of Vesuvius +on the occasion of that memorable eruption which buried the cities of +Herculaneum and Pompeii. + +Doubtless the wandering life of the soldier had given Pliny abundant +opportunity for personal observation in his favorite fields of botany +and zoology. But the records of his own observations are so intermingled +with knowledge drawn from books that it is difficult to distinguish +the one from the other. Nor does this greatly matter, for whether as +closet-student or field-naturalist, Pliny's trait of mind is essentially +that of the compiler. He was no philosophical thinker, no generalizer, +no path-maker in science. He lived at the close of a great progressive +epoch of thought; in one of those static periods when numberless +observers piled up an immense mass of details which might advantageously +be sorted into a kind of encyclopaedia. Such an encyclopaedia is the +so-called Natural History of Pliny. It is a vast jumble of more or +less uncritical statements regarding almost every field of contemporary +knowledge. The descriptions of animals and plants predominate, but the +work as a whole would have been immensely improved had the compiler +shown a more critical spirit. As it is, he seems rather disposed to +quote any interesting citation that he comes across in his omnivorous +readings, shielding himself behind an equivocal "it is said," or "so and +so alleges." A single illustration will suffice to show what manner of +thing is thought worthy of repetition. + +"It is asserted," he says, "that if the fish called a sea-star is +smeared with the fox's blood and then nailed to the upper lintel of the +door, or to the door itself, with a copper nail, no noxious spell will +be able to obtain admittance, or, at all events, be productive of any +ill effects." + +It is easily comprehensible that a work fortified with such practical +details as this should have gained wide popularity. Doubtless the +natural histories of our own day would find readier sale were they to +pander to various superstitions not altogether different from that here +suggested. The man, for example, who believes that to have a black cat +cross his path is a lucky omen would naturally find himself attracted +by a book which took account of this and similar important details +of natural history. Perhaps, therefore, it was its inclusion of +absurdities, quite as much as its legitimate value, that gave vogue to +the celebrated work of Pliny. But be that as it may, the most famous +scientist of Rome must be remembered as a popular writer rather than as +an experimental worker. In the history of the promulgation of scientific +knowledge his work is important; in the history of scientific principles +it may virtually be disregarded. + + +PTOLEMY, THE LAST GREAT ASTRONOMER OF ANTIQUITY + +Almost the same thing may be said of Ptolemy, an even more celebrated +writer, who was born not very long after the death of Pliny. The exact +dates of Ptolemy's life are not known, but his recorded observations +extend to the year 151 A.D. He was a working astronomer, and he made +at least one original discovery of some significance--namely, the +observation of a hitherto unrecorded irregularity of the moon's motion, +which came to be spoken of as the moon's evection. This consists of +periodical aberrations from the moon's regular motion in its orbit, +which, as we now know, are due to the gravitation pull of the sun, but +which remained unexplained until the time of Newton. Ptolemy also +made original observations as to the motions of the planets. He is, +therefore, entitled to a respectable place as an observing astronomer; +but his chief fame rests on his writings. + +His great works have to do with geography and astronomy. In the former +field he makes an advance upon Strabo, citing the latitude of no fewer +than five thousand places. In the field of astronomy, his great service +was to have made known to the world the labors of Hipparchus. Ptolemy +has been accused of taking the star-chart of his great predecessor +without due credit, and indeed it seems difficult to clear him of +this charge. Yet it is at least open to doubt whether he intended any +impropriety, inasmuch as he all along is sedulous in his references to +his predecessor. Indeed, his work might almost be called an exposition +of the astronomical doctrines of Hipparchus. No one pretends that +Ptolemy is to be compared with the Rhodesian observer as an original +investigator, but as a popular expounder his superiority is evidenced +in the fact that the writings of Ptolemy became practically the sole +astronomical text-book of the Middle Ages both in the East and in the +West, while the writings of Hipparchus were allowed to perish. + +The most noted of all the writings of Ptolemy is the work which became +famous under the Arabic name of Almagest. This word is curiously +derived from the Greek title (gr h megisth suntazis), "the greatest +construction," a name given the book to distinguish it from a work on +astrology in four books by the same author. For convenience of reference +it came to be spoken of merely as (gr h megisth), from which the Arabs +form the title Tabair al Magisthi, under which title the book was +published in the year 827. From this it derived the word Almagest, +by which Ptolemy's work continued to be known among the Arabs, and +subsequently among Europeans when the book again became known in the +West. Ptolemy's book, as has been said, is virtually an elaboration +of the doctrines of Hipparchus. It assumes that the earth is the fixed +centre of the solar system, and that the stars and planets revolve about +it in twenty-four hours, the earth being, of course, spherical. It was +not to be expected that Ptolemy should have adopted the heliocentric +idea of Aristarchus. Yet it is much to be regretted that he failed to do +so, since the deference which was accorded his authority throughout the +Middle Ages would doubtless have been extended in some measure at +least to this theory as well, had he championed it. Contrariwise, his +unqualified acceptance of the geocentric doctrine sufficed to place that +doctrine beyond the range of challenge. + +The Almagest treats of all manner of astronomical problems, but the +feature of it which gained it widest celebrity was perhaps that which +has to do with eccentrics and epicycles. This theory was, of course, but +an elaboration of the ideas of Hipparchus; but, owing to the celebrity +of the expositor, it has come to be spoken of as the theory of Ptolemy. +We have sufficiently detailed the theory in speaking of Hipparchus. It +should be explained, however, that, with both Hipparchus and Ptolemy, +the theory of epicycles would appear to have been held rather as a +working hypothesis than as a certainty, so far as the actuality of +the minor spheres or epicycles is concerned. That is to say, these +astronomers probably did not conceive either the epicycles or the +greater spheres as constituting actual solid substances. Subsequent +generations, however, put this interpretation upon the theory, +conceiving the various spheres as actual crystalline bodies. It is +difficult to imagine just how the various epicycles were supposed to +revolve without interfering with the major spheres, but perhaps this is +no greater difficulty than is presented by the alleged properties of +the ether, which physicists of to-day accept as at least a working +hypothesis. We shall see later on how firmly the conception of +concentric crystalline spheres was held to, and that no real challenge +was ever given that theory until the discovery was made that comets +have an orbit that must necessarily intersect the spheres of the various +planets. + +Ptolemy's system of geography in eight books, founded on that of Marinus +of Tyre, was scarcely less celebrated throughout the Middle Ages than +the Almagest. It contained little, however, that need concern us here, +being rather an elaboration of the doctrines to which we have already +sufficiently referred. None of Ptolemy's original manuscripts has come +down to us, but there is an alleged fifth-century manuscript attributed +to Agathadamon of Alexandria which has peculiar interest because it +contains a series of twenty-seven elaborately colored maps that are +supposed to be derived from maps drawn up by Ptolemy himself. In these +maps the sea is colored green, the mountains red or dark yellow, and the +land white. Ptolemy assumed that a degree at the equator was 500 stadia +instead of 604 stadia in length. We are not informed as to the grounds +on which this assumption was made, but it has been suggested that the +error was at least partially instrumental in leading to one very +curious result. "Taking the parallel of Rhodes," says Donaldson,(5) "he +calculated the longitudes from the Fortunate Islands to Cattigara or the +west coast of Borneo at 180 degrees, conceiving this to be one-half the +circumference of the globe. The real distance is only 125 degrees or +127 degrees, so that his measurement is wrong by one third of the whole, +one-sixth for the error in the measurement of a degree and one-sixth for +the errors in measuring the distance geometrically. These errors, owing +to the authority attributed to the geography of Ptolemy in the Middle +Ages, produced a consequence of the greatest importance. They really led +to the discovery of America. For the design of Columbus to sail from the +west of Europe to the east of Asia was founded on the supposition that +the distance was less by one third than it really was." This view is +perhaps a trifle fanciful, since there is nothing to suggest that the +courage of Columbus would have balked at the greater distance, and since +the protests of the sailors, which nearly thwarted his efforts, were +made long before the distance as estimated by Ptolemy had been covered; +nevertheless it is interesting to recall that the great geographical +doctrines, upon which Columbus must chiefly have based his arguments, +had been before the world in an authoritative form practically unheeded +for more than twelve hundred years, awaiting a champion with courage +enough to put them to the test. + + +GALEN--THE LAST GREAT ALEXANDRIAN + +There is one other field of scientific investigation to which we must +give brief attention before leaving the antique world. This is the field +of physiology and medicine. In considering it we shall have to do +with the very last great scientist of the Alexandrian school. This was +Claudius Galenus, commonly known as Galen, a man whose fame was destined +to eclipse that of all other physicians of antiquity except Hippocrates, +and whose doctrines were to have the same force in their field +throughout the Middle Ages that the doctrines of Aristotle had for +physical science. But before we take up Galen's specific labors, it will +be well to inquire briefly as to the state of medical art and science in +the Roman world at the time when the last great physician of antiquity +came upon the scene. + +The Romans, it would appear, had done little in the way of scientific +discoveries in the field of medicine, but, nevertheless, with their +practicality of mind, they had turned to better account many more of +the scientific discoveries of the Greeks than did the discoverers +themselves. The practising physicians in early Rome were mostly men of +Greek origin, who came to the capital after the overthrow of the Greeks +by the Romans. Many of them were slaves, as earning money by either +bodily or mental labor was considered beneath the dignity of a Roman +citizen. The wealthy Romans, who owned large estates and numerous +slaves, were in the habit of purchasing some of these slave doctors, and +thus saving medical fees by having them attend to the health of their +families. + +By the beginning of the Christian era medicine as a profession had +sadly degenerated, and in place of a class of physicians who practised +medicine along rational or legitimate lines, in the footsteps of the +great Hippocrates, there appeared great numbers of "specialists," most +of them charlatans, who pretended to possess supernatural insight in the +methods of treating certain forms of disease. These physicians rightly +earned the contempt of the better class of Romans, and were made the +object of many attacks by the satirists of the time. Such specialists +travelled about from place to place in much the same manner as the +itinerant "Indian doctors" and "lightning tooth-extractors" do to-day. +Eye-doctors seem to have been particularly numerous, and these were +divided into two classes, eye-surgeons and eye-doctors proper. The +eye-surgeon performed such operations as cauterizing for ingrowing +eyelashes and operating upon growths about the eyes; while the +eye-doctors depended entirely upon salves and lotions. These eye-salves +were frequently stamped with the seal of the physician who compounded +them, something like two hundred of these seals being still in +existence. There were besides these quacks, however, reputable +eye-doctors who must have possessed considerable skill in the treatment +of certain ophthalmias. Among some Roman surgical instruments discovered +at Rheims were found also some drugs employed by ophthalmic surgeons, +and an analysis of these show that they contained, among other +ingredients, some that are still employed in the treatment of certain +affections of the eye. + +One of the first steps taken in recognition of the services of +physicians was by Julius Caesar, who granted citizenship to all +physicians practising in Rome. This was about fifty years before the +Christian era, and from that time on there was a gradual improvement +in the attitude of the Romans towards the members of the medical +profession. As the Romans degenerated from a race of sturdy warriors and +became more and more depraved physically, the necessity for physicians +made itself more evident. Court physicians, and physicians-in-ordinary, +were created by the emperors, as were also city and district physicians. +In the year 133 A.D. Hadrian granted immunity from taxes and military +service to physicians in recognition of their public services. + +The city and district physicians, known as the archiatri populaires, +treated and cared for the poor without remuneration, having a position +and salary fixed by law and paid them semi-annually. These were +honorable positions, and the archiatri were obliged to give instruction +in medicine, without pay, to the poor students. They were allowed to +receive fees and donations from their patients, but not, however, +until the danger from the malady was past. Special laws were enacted to +protect them, and any person subjecting them to an insult was liable to +a fine "not exceeding one thousand pounds." + +An example of Roman practicality is shown in the method of treating +hemorrhage, as described by Aulus Cornelius Celsus (53 B.C. to 7 A.D.). +Hippocrates and Hippocratic writers treated hemorrhage by application of +cold, pressure, styptics, and sometimes by actual cauterizing; but they +knew nothing of the simple method of stopping a hemorrhage by a ligature +tied around the bleeding vessel. Celsus not only recommended tying the +end of the injured vessel, but describes the method of applying two +ligatures before the artery is divided by the surgeon--a common practice +among surgeons at the present time. The cut is made between these two, +and thus hemorrhage is avoided from either end of the divided vessel. + +Another Roman surgeon, Heliodorus, not only describes the use of +the ligature in stopping hemorrhage, but also the practice of +torsion--twisting smaller vessels, which causes their lining membrane to +contract in a manner that produces coagulation and stops hemorrhage. It +is remarkable that so simple and practical a method as the use of the +ligature in stopping hemorrhage could have gone out of use, once it had +been discovered; but during the Middle Ages it was almost entirely lost +sight of, and was not reintroduced until the time of Ambroise Pare, in +the sixteenth century. + +Even at a very early period the Romans recognized the advantage of +surgical methods on the field of battle. Each soldier was supplied with +bandages, and was probably instructed in applying them, something in the +same manner as is done now in all modern armies. The Romans also made +use of military hospitals and had established a rude but very practical +field-ambulance service. "In every troop or bandon of two or four +hundred men, eight or ten stout fellows were deputed to ride immediately +behind the fighting-line to pick up and rescue the wounded, for which +purpose their saddles had two stirrups on the left side, while they +themselves were provided with water-flasks, and perhaps applied +temporary bandages. They were encouraged by a reward of a piece of gold +for each man they rescued. 'Noscomi' were male nurses attached to the +military hospitals, but not inscribed 'on strength' of the legions, and +were probably for the most part of the servile class."(6) + +From the time of the early Alexandrians, Herophilus and Erasistratus, +whose work we have already examined, there had been various anatomists +of some importance in the Alexandrian school, though none quite equal to +these earlier workers. The best-known names are those of Celsus (of +whom we have already spoken), who continued the work of anatomical +investigation, and Marinus, who lived during the reign of Nero, +and Rufus of Ephesus. Probably all of these would have been better +remembered by succeeding generations had their efforts not been eclipsed +by those of Galen. This greatest of ancient anatomists was born at +Pergamus of Greek parents. His father, Nicon, was an architect and a man +of considerable ability. Until his fifteenth year the youthful Galen was +instructed at home, chiefly by his father; but after that time he was +placed under suitable teachers for instruction in the philosophical +systems in vogue at that period. Shortly after this, however, the +superstitious Nicon, following the interpretations of a dream, decided +that his son should take up the study of medicine, and placed him under +the instruction of several learned physicians. + +Galen was a tireless worker, making long tours into Asia Minor and +Palestine to improve himself in pharmacology, and studying anatomy +for some time at Alexandria. He appears to have been full of the +superstitions of the age, however, and early in his career made +an extended tour into western Asia in search of the chimerical +"jet-stone"--a stone possessing the peculiar qualities of "burning with +a bituminous odor and supposed to possess great potency in curing such +diseases as epilepsy, hysteria, and gout." + +By the time he had reached his twenty-eighth year he had perfected his +education in medicine and returned to his home in Pergamus. Even at +that time he had acquired considerable fame as a surgeon, and his +fellow-citizens showed their confidence in his ability by choosing him +as surgeon to the wounded gladiators shortly after his return to his +native city. In these duties his knowledge of anatomy aided him +greatly, and he is said to have healed certain kinds of wounds that had +previously baffled the surgeons. + +In the time of Galen dissections of the human body were forbidden by +law, and he was obliged to confine himself to dissections of the lower +animals. He had the advantage, however, of the anatomical works of +Herophilus and Erasistratus, and he must have depended upon them in +perfecting his comparison between the anatomy of men and the +lower animals. It is possible that he did make human dissections +surreptitiously, but of this we have no proof. + +He was familiar with the complicated structure of the bones of the +cranium. He described the vertebrae clearly, divided them into groups, +and named them after the manner of anatomists of to-day. He was less +accurate in his description of the muscles, although a large number +of these were described by him. Like all anatomists before the time of +Harvey, he had a very erroneous conception of the circulation, although +he understood that the heart was an organ for the propulsion of blood, +and he showed that the arteries of the living animals did not contain +air alone, as was taught by many anatomists. He knew, also, that +the heart was made up of layers of fibres that ran in certain fixed +directions--that is, longitudinal, transverse, and oblique; but he did +not recognize the heart as a muscular organ. In proof of this he pointed +out that all muscles require rest, and as the heart did not rest it +could not be composed of muscular tissue. + +Many of his physiological experiments were conducted upon scientific +principles. Thus he proved that certain muscles were under the control +of definite sets of nerves by cutting these nerves in living animals, +and observing that the muscles supplied by them were rendered useless. +He pointed out also that nerves have no power in themselves, but merely +conduct impulses to and from the brain and spinal-cord. He turned this +peculiar knowledge to account in the case of a celebrated sophist, +Pausanias, who had been under the treatment of various physicians for +a numbness in the fourth and fifth fingers of his left hand. These +physicians had been treating this condition by applications of poultices +to the hand itself. Galen, being called in consultation, pointed out +that the injury was probably not in the hand itself, but in the ulner +nerve, which controls sensation in the fourth and fifth fingers. +Surmising that the nerve must have been injured in some way, he made +careful inquiries of the patient, who recalled that he had been thrown +from his chariot some time before, striking and injuring his back. +Acting upon this information, Galen applied stimulating remedies to the +source of the nerve itself--that is, to the bundle of nerve-trunks known +as the brachial plexus, in the shoulder. To the surprise and confusion +of his fellow-physicians, this method of treatment proved effective and +the patient recovered completely in a short time. + +Although the functions of the organs in the chest were not well +understood by Galen, he was well acquainted with their anatomy. He knew +that the lungs were covered by thin membrane, and that the heart was +surrounded by a sac of very similar tissue. He made constant comparisons +also between these organs in different animals, as his dissections were +performed upon beasts ranging in size from a mouse to an elephant. The +minuteness of his observations is shown by the fact that he had noted +and described the ring of bone found in the hearts of certain animals, +such as the horse, although not found in the human heart or in most +animals. + +His description of the abdominal organs was in general accurate. He +had noted that the abdominal cavity was lined with a peculiar saclike +membrane, the peritoneum, which also surrounded most of the organs +contained in the cavity, and he made special note that this membrane +also enveloped the liver in a peculiar manner. The exactness of the last +observation seems the more wonderful when we reflect that even to-day +the medical, student finds a correct understanding of the position +of the folds of the peritoneum one of the most difficult subjects in +anatomy. + +As a practical physician he was held in the highest esteem by the +Romans. The Emperor Marcus Aurelius called him to Rome and appointed +him physician-inordinary to his son Commodus, and on special occasions +Marcus Aurelius himself called in Galen as his medical adviser. On +one occasion, the three army surgeons in attendance upon the emperor +declared that he was about to be attacked by a fever. Galen relates +how "on special command I felt his pulse, and finding it quite normal, +considering his age and the time of day, I declared it was no fever +but a digestive disorder, due to the food he had eaten, which must be +converted into phlegm before being excreted. Then the emperor repeated +three times, 'That's the very thing,' and asked what was to be done. I +answered that I usually gave a glass of wine with pepper sprinkled +on it, but for you kings we only use the safest remedies, and it will +suffice to apply wool soaked in hot nard ointment locally. The emperor +ordered the wool, wine, etc., to be brought, and I left the room. His +feet were warmed by rubbing with hot hands, and after drinking the +peppered wine, he said to Pitholaus (his son's tutor), 'We have only one +doctor, and that an honest one,' and went on to describe me as the first +of physicians and the only philosopher, for he had tried many before who +were not only lovers of money, but also contentious, ambitious, envious, +and malignant."(7) + +It will be seen from this that Galen had a full appreciation of his own +abilities as a physician, but inasmuch as succeeding generations for +a thousand years concurred in the alleged statement made by Marcus +Aurelius as to his ability, he is perhaps excusable for his open avowal +of his belief in his powers. His faith in his accuracy in diagnosis and +prognosis was shown when a colleague once said to him, "I have used the +prognostics of Hippocrates as well as you. Why can I not prognosticate +as well as you?" To this Galen replied, "By God's help I have never been +deceived in my prognosis."(8) It is probable that this statement was +made in the heat of argument, and it is hardly to be supposed that he +meant it literally. + +His systems of treatment were far in advance of his theories regarding +the functions of organs, causes of disease, etc., and some of them are +still first principles with physicians. Like Hippocrates, he laid great +stress on correct diet, exercise, and reliance upon nature. "Nature is +the overseer by whom health is supplied to the sick," he says. "Nature +lends her aid on all sides, she decides and cures diseases. No one can +be saved unless nature conquers the disease, and no one dies unless +nature succumbs." + +From the picture thus drawn of Galen as an anatomist and physician, one +might infer that he should rank very high as a scientific exponent of +medicine, even in comparison with modern physicians. There is, however, +another side to the picture. His knowledge of anatomy was certainly +very considerable, but many of his deductions and theories as to the +functions of organs, the cause of diseases, and his methods of treating +them, would be recognized as absurd by a modern school-boy of average +intelligence. His greatness must be judged in comparison with +ancient, not with modern, scientists. He maintained, for example, that +respiration and the pulse-beat were for one and the same purpose--that +of the reception of air into the arteries of the body. To him the act of +breathing was for the purpose of admitting air into the lungs, whence it +found its way into the heart, and from there was distributed throughout +the body by means of the arteries. The skin also played an important +part in supplying the body with air, the pores absorbing the air and +distributing it through the arteries. But, as we know that he was +aware of the fact that the arteries also contained blood, he must have +believed that these vessels contained a mixture of the two. + +Modern anatomists know that the heart is divided into two approximately +equal parts by an impermeable septum of tough fibres. Yet, Galen, who +dissected the hearts of a vast number of the lower animals according to +his own account, maintained that this septum was permeable, and that the +air, entering one side of the heart from the lungs, passed through it +into the opposite side and was then transferred to the arteries. + +He was equally at fault, although perhaps more excusably so, in his +explanation of the action of the nerves. He had rightly pointed out that +nerves were merely connections between the brain and spinal-cord and +distant muscles and organs, and had recognized that there were two kinds +of nerves, but his explanation of the action of these nerves was +that "nervous spirits" were carried to the cavities of the brain by +blood-vessels, and from there transmitted through the body along the +nerve-trunks. + +In the human skull, overlying the nasal cavity, there are two thin +plates of bone perforated with numerous small apertures. These apertures +allow the passage of numerous nerve-filaments which extend from a group +of cells in the brain to the delicate membranes in the nasal cavity. +These perforations in the bone, therefore, are simply to allow the +passage of the nerves. But Galen gave a very different explanation. He +believed that impure "animal spirits" were carried to the cavities of +the brain by the arteries in the neck and from there were sifted out +through these perforated bones, and so expelled from the body. + +He had observed that the skin played an important part in cooling the +body, but he seems to have believed that the heart was equally active +in overheating it. The skin, therefore, absorbed air for the purpose of +"cooling the heart," and this cooling process was aided by the brain, +whose secretions aided also in the cooling process. The heart itself was +the seat of courage; the brain the seat of the rational soul; and the +liver the seat of love. + +The greatness of Galen's teachings lay in his knowledge of anatomy of +the organs; his weakness was in his interpretations of their functions. +Unfortunately, succeeding generations of physicians for something like a +thousand years rejected the former but clung to the latter, so that the +advances he had made were completely overshadowed by the mistakes of his +teachings. + + + + +XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +It is a favorite tenet of the modern historian that history is a +continuous stream. The contention has fullest warrant. Sharp lines of +demarcation are an evidence of man's analytical propensity rather than +the work of nature. Nevertheless it would be absurd to deny that the +stream of history presents an ever-varying current. There are times +when it seems to rush rapidly on; times when it spreads out into a +broad--seemingly static--current; times when its catastrophic changes +remind us of nothing but a gigantic cataract. Rapids and whirlpools, +broad estuaries and tumultuous cataracts are indeed part of the same +stream, but they are parts that vary one from another in their salient +features in such a way as to force the mind to classify them as things +apart and give them individual names. + +So it is with the stream of history; however strongly we insist on its +continuity we are none the less forced to recognize its periodicity. It +may not be desirable to fix on specific dates as turning-points to the +extent that our predecessors were wont to do. We may not, for example, +be disposed to admit that the Roman Empire came to any such cataclysmic +finish as the year 476 A.D., when cited in connection with the overthrow +of the last Roman Empire of the West, might seem to indicate. But, on +the other hand, no student of the period can fail to realize that a +great change came over the aspect of the historical stream towards the +close of the Roman epoch. + +The span from Thales to Galen has compassed about eight hundred +years--let us say thirty generations. Throughout this period there +is scarcely a generation that has not produced great scientific +thinkers--men who have put their mark upon the progress of civilization; +but we shall see, as we look forward for a corresponding period, that +the ensuing thirty generations produced scarcely a single scientific +thinker of the first rank. Eight hundred years of intellectual +activity--thirty generations of greatness; then eight hundred years of +stasis--thirty generations of mediocrity; such seems to be the record +as viewed in perspective. Doubtless it seemed far different to the +contemporary observer; it is only in reasonable perspective that any +scene can be viewed fairly. But for us, looking back without prejudice +across the stage of years, it seems indisputable that a great epoch came +to a close at about the time when the barbarian nations of Europe began +to sweep down into Greece and Italy. We are forced to feel that we have +reached the limits of progress of what historians are pleased to call +the ancient world. For about eight hundred years Greek thought has been +dominant, but in the ensuing period it is to play a quite subordinate +part, except in so far as it influences the thought of an alien race. As +we leave this classical epoch, then, we may well recapitulate in brief +its triumphs. A few words will suffice to summarize a story the details +of which have made up our recent chapters. + +In the field of cosmology, Greek genius has demonstrated that the earth +is spheroidal, that the moon is earthlike in structure and much smaller +than our globe, and that the sun is vastly larger and many times more +distant than the moon. The actual size of the earth and the angle of its +axis with the ecliptic have been measured with approximate accuracy. +It has been shown that the sun and moon present inequalities of motion +which may be theoretically explained by supposing that the earth is not +situated precisely at the centre of their orbits. A system of eccentrics +and epicycles has been elaborated which serves to explain the apparent +motions of the heavenly bodies in a manner that may be called scientific +even though it is based, as we now know, upon a false hypothesis. The +true hypothesis, which places the sun at the centre of the planetary +system and postulates the orbital and axial motions of our earth in +explanation of the motions of the heavenly bodies, has been put forward +and ardently championed, but, unfortunately, is not accepted by the +dominant thinkers at the close of our epoch. In this regard, therefore, +a vast revolutionary work remains for the thinkers of a later period. +Moreover, such observations as the precession of the equinoxes and the +moon's evection are as yet unexplained, and measurements of the earth's +size, and of the sun's size and distance, are so crude and imperfect as +to be in one case only an approximation, and in the other an absurdly +inadequate suggestion. But with all these defects, the total achievement +of the Greek astronomers is stupendous. To have clearly grasped the idea +that the earth is round is in itself an achievement that marks off the +classical from the Oriental period as by a great gulf. + +In the physical sciences we have seen at least the beginnings of great +things. Dynamics and hydrostatics may now, for the first time, claim a +place among the sciences. Geometry has been perfected and trigonometry +has made a sure beginning. The conception that there are four elementary +substances, earth, water, air, and fire, may not appear a secure +foundation for chemistry, yet it marks at least an attempt in the right +direction. Similarly, the conception that all matter is made up of +indivisible particles and that these have adjusted themselves and are +perhaps held in place by a whirling motion, while it is scarcely more +than a scientific dream, is, after all, a dream of marvellous insight. + +In the field of biological science progress has not been so marked, yet +the elaborate garnering of facts regarding anatomy, physiology, and +the zoological sciences is at least a valuable preparation for the +generalizations of a later time. + +If with a map before us we glance at the portion of the globe which was +known to the workers of the period now in question, bearing in mind +at the same time what we have learned as to the seat of labors of the +various great scientific thinkers from Thales to Galen, we cannot fail +to be struck with a rather startling fact, intimations of which have +been given from time to time--the fact, namely, that most of the great +Greek thinkers did not live in Greece itself. As our eye falls upon Asia +Minor and its outlying islands, we reflect that here were born such men +as Thales, Anaximander, Anaximenes, Heraclitus, Pythagoras, Anaxagoras, +Socrates, Aristarchus, Hipparchus, Eudoxus, Philolaus, and Galen. +From the northern shores of the aegean came Lucippus, Democritus, +and Aristotle. Italy, off to the west, is the home of Pythagoras and +Xenophanes in their later years, and of Parmenides and Empedocles, Zeno, +and Archimedes. Northern Africa can claim, by birth or by adoption, +such names as Euclid, Apollonius of Perga, Herophilus, Erasistratus, +Aristippus, Eratosthenes, Ctesibius, Hero, Strabo, and Ptolemy. This is +but running over the list of great men whose discoveries have claimed +our attention. Were we to extend the list to include a host of workers +of the second rank, we should but emphasize the same fact. + +All along we are speaking of Greeks, or, as they call themselves, +Hellenes, and we mean by these words the people whose home was a small +jagged peninsula jutting into the Mediterranean at the southeastern +extremity of Europe. We think of this peninsula as the home of Greek +culture, yet of all the great thinkers we have just named, not one was +born on this peninsula, and perhaps not one in five ever set foot upon +it. In point of fact, one Greek thinker of the very first rank, and one +only, was born in Greece proper; that one, however, was Plato, perhaps +the greatest of them all. With this one brilliant exception (and even he +was born of parents who came from the provinces), all the great thinkers +of Greece had their origin at the circumference rather than the centre +of the empire. And if we reflect that this circumference of the Greek +world was in the nature of the case the widely circling region in which +the Greek came in contact with other nations, we shall see at once that +there could be no more striking illustration in all history than that +furnished us here of the value of racial mingling as a stimulus to +intellectual progress. + +But there is one other feature of the matter that must not be +overlooked. Racial mingling gives vitality, but to produce the best +effect the mingling must be that of races all of which are at a +relatively high plane of civilization. In Asia Minor the Greek mingled +with the Semite, who had the heritage of centuries of culture; and in +Italy with the Umbrians, Oscans, and Etruscans, who, little as we know +of their antecedents, have left us monuments to testify to their high +development. The chief reason why the racial mingling of a later day did +not avail at once to give new life to Roman thought was that the races +which swept down from the north were barbarians. It was no more possible +that they should spring to the heights of classical culture than it +would, for example, be possible in two or three generations to produce a +racer from a stock of draught horses. Evolution does not proceed by +such vaults as this would imply. Celt, Goth, Hun, and Slav must undergo +progressive development for many generations before the population of +northern Europe can catch step with the classical Greek and prepare to +march forward. That, perhaps, is one reason why we come to a period of +stasis or retrogression when the time of classical activity is over. +But, at best, it is only one reason of several. + +The influence of the barbarian nations will claim further attention as +we proceed. But now, for the moment, we must turn our eyes in the other +direction and give attention to certain phases of Greek and of Oriental +thought which were destined to play a most important part in the +development of the Western mind--a more important part, indeed, in the +early mediaeval period than that played by those important inductions of +science which have chiefly claimed our attention in recent chapters. +The subject in question is the old familiar one of false inductions or +pseudoscience. In dealing with the early development of thought and with +Oriental science, we had occasion to emphasize the fact that such false +inductions led everywhere to the prevalence of superstition. In dealing +with Greek science, we have largely ignored this subject, confining +attention chiefly to the progressive phases of thought; but it must +not be inferred from this that Greek science, with all its secure +inductions, was entirely free from superstition. On the contrary, the +most casual acquaintance with Greek literature would suffice to show the +incorrectness of such a supposition. True, the great thinkers of Greece +were probably freer from this thraldom of false inductions than any +of their predecessors. Even at a very early day such men as Xenophanes, +Empedocles, Anaxagoras, and Plato attained to a singularly rationalistic +conception of the universe. + +We saw that "the father of medicine," Hippocrates, banished demonology +and conceived disease as due to natural causes. At a slightly later day +the sophists challenged all knowledge, and Pyrrhonism became a synonym +for scepticism in recognition of the leadership of a master doubter. +The entire school of Alexandrians must have been relatively free from +superstition, else they could not have reasoned with such effective +logicality from their observations of nature. It is almost inconceivable +that men like Euclid and Archimedes, and Aristarchus and Eratosthenes, +and Hipparchus and Hero, could have been the victims of such illusions +regarding occult forces of nature as were constantly postulated by +Oriental science. Herophilus and Erasistratus and Galen would hardly +have pursued their anatomical studies with equanimity had they believed +that ghostly apparitions watched over living and dead alike, and +exercised at will a malign influence. + +Doubtless the Egyptian of the period considered the work, of the +Ptolemaic anatomists an unspeakable profanation, and, indeed, it was +nothing less than revolutionary--so revolutionary that it could not be +sustained in subsequent generations. We have seen that the great Galen, +at Rome, five centuries after the time of Herophilus, was prohibited +from dissecting the human subject. The fact speaks volumes for the +attitude of the Roman mind towards science. Vast audiences made up +of every stratum of society thronged the amphitheatre, and watched +exultingly while man slew his fellow-man in single or in multiple +combat. Shouts of frenzied joy burst from a hundred thousand throats +when the death-stroke was given to a new victim. The bodies of the +slain, by scores, even by hundreds, were dragged ruthlessly from the +arena and hurled into a ditch as contemptuously as if pity were +yet unborn and human life the merest bauble. Yet the same eyes that +witnessed these scenes with ecstatic approval would have been averted +in pious horror had an anatomist dared to approach one of the mutilated +bodies with the scalpel of science. It was sport to see the blade of the +gladiator enter the quivering, living flesh of his fellow-gladiator; it +was joy to see the warm blood spurt forth from the writhing victim while +he still lived; but it were sacrilegious to approach that body with the +knife of the anatomist, once it had ceased to pulsate with life. Life +itself was held utterly in contempt, but about the realm of death +hovered the threatening ghosts of superstition. And such, be it +understood, was the attitude of the Roman populace in the early and the +most brilliant epoch of the empire, before the Western world came +under the influence of that Oriental philosophy which was presently to +encompass it. + +In this regard the Alexandrian world was, as just intimated, far more +advanced than the Roman, yet even there we must suppose that the leaders +of thought were widely at variance with the popular conceptions. A few +illustrations, drawn from Greek literature at various ages, will suggest +the popular attitude. In the first instance, consider the poems of Homer +and of Hesiod. For these writers, and doubtless for the vast majority +of their readers, not merely of their own but of many subsequent +generations, the world is peopled with a multitude of invisible +apparitions, which, under title of gods, are held to dominate the +affairs of man. It is sometimes difficult to discriminate as to where +the Greek imagination drew the line between fact and allegory; nor need +we attempt to analyse the early poetic narratives to this end. It will +better serve our present purpose to cite three or four instances which +illustrate the tangibility of beliefs based upon pseudo-scientific +inductions. + +Let us cite, for example, the account which Herodotus gives us of the +actions of the Greeks at Plataea, when their army confronted the remnant +of the army of Xerxes, in the year 479 B.C. Here we see each side +hesitating to attack the other, merely because the oracle had declared +that whichever side struck the first blow would lose the conflict. Even +after the Persian soldiers, who seemingly were a jot less superstitious +or a shade more impatient than their opponents, had begun the attack, +we are told that the Greeks dared not respond at first, though they +were falling before the javelins of the enemy, because, forsooth, the +entrails of a fowl did not present an auspicious appearance. And these +were Greeks of the same generation with Empedocles and Anaxagoras and +aeschylus; of the same epoch with Pericles and Sophocles and Euripides +and Phidias. Such was the scientific status of the average mind--nay, of +the best minds--with here and there a rare exception, in the golden age +of Grecian culture. + +Were we to follow down the pages of Greek history, we should but repeat +the same story over and over. We should, for example, see Alexander +the Great balked at the banks of the Hyphasis, and forced to turn back +because of inauspicious auguries based as before upon the dissection of +a fowl. Alexander himself, to be sure, would have scorned the augury; +had he been the prey of such petty superstitions he would never have +conquered Asia. We know how he compelled the oracle at Delphi to yield +to his wishes; how he cut the Gordian knot; how he made his dominating +personality felt at the temple of Ammon in Egypt. We know, in a word, +that he yielded to superstitions only in so far as they served his +purpose. Left to his own devices, he would not have consulted an oracle +at the banks of the Hyphasis; or, consulting, would have forced from the +oracle a favorable answer. But his subordinates were mutinous and he +had no choice. Suffice it for our present purpose that the oracle was +consulted, and that its answer turned the conqueror back. + +One or two instances from Roman history may complete the picture. +Passing over all those mythical narratives which virtually constitute +the early history of Rome, as preserved to us by such historians as Livy +and Dionysius, we find so logical an historian as Tacitus recording a +miraculous achievement of Vespasian without adverse comment. "During +the months when Vespasian was waiting at Alexandria for the periodical +season of the summer winds, and a safe navigation, many miracles +occurred by which the favor of Heaven and a sort of bias in the powers +above towards Vespasian were manifested." Tacitus then describes in +detail the cure of various maladies by the emperor, and relates that +the emperor on visiting a temple was met there, in the spirit, by a +prominent Egyptian who was proved to be at the same time some eighty +miles distant from Alexandria. + +It must be admitted that Tacitus, in relating that Vespasian caused the +blind to see and the lame to walk, qualifies his narrative by asserting +that "persons who are present attest the truth of the transaction when +there is nothing to be gained by falsehood." Nor must we overlook the +fact that a similar belief in the power of royalty has persisted almost +to our own day. But no such savor of scepticism attaches to a narrative +which Dion Cassius gives us of an incident in the life of Marcus +Aurelius--an incident that has become famous as the episode of The +Thundering Legion. Xiphilinus has preserved the account of Dion, adding +certain picturesque interpretations of his own. The original narrative, +as cited, asserts that during one of the northern campaigns of Marcus +Aurelius, the emperor and his army were surrounded by the hostile Quadi, +who had every advantage of position and who presently ceased hostilities +in the hope that heat and thirst would deliver their adversaries into +their hands without the trouble of further fighting. "Now," says Dion, +"while the Romans, unable either to combat or to retreat, and reduced to +the last extremity by wounds, fatigue, heat, and thirst, were standing +helplessly at their posts, clouds suddenly gathered in great number and +rain descended in floods--certainly not without divine intervention, +since the Egyptian Maege Arnulphis, who was with Marcus Antoninus, is +said to have invoked several genii by the aerial mercury by enchantment, +and thus through them had brought down rain." + +Here, it will be observed, a supernatural explanation is given of a +natural phenomenon. But the narrator does not stop with this. If we are +to accept the account of Xiphilinus, Dion brings forward some striking +proofs of divine interference. Xiphilinus gives these proofs in the +following remarkable paragraph: + +"Dion adds that when the rain began to fall every soldier lifted his +head towards heaven to receive the water in his mouth; but afterwards +others hold out their shields or their helmets to catch the water for +themselves and for their horses. Being set upon by the barbarians... +while occupied in drinking, they would have been seriously incommoded +had not heavy hail and numerous thunderbolts thrown consternation into +the ranks of the enemy. Fire and water were seen to mingle as they left +the heavens. The fire, however, did not reach the Romans, but if it did +by chance touch one of them it was immediately extinguished, while at +the same time the rain, instead of comforting the barbarians, seemed +merely to excite like oil the fire with which they were being consumed. +Some barbarians inflicted wounds upon themselves as though their blood +had power to extinguish flames, while many rushed over to the side of +the Romans, hoping that there water might save them." + +We cannot better complete these illustrations of pagan credulity than by +adding the comment of Xiphilinus himself. That writer was a Christian, +living some generations later than Dion. He never thought of questioning +the facts, but he felt that Dion's interpretation of these facts must +not go unchallenged. As he interprets the matter, it was no pagan +magician that wrought the miracle. He even inclines to the belief that +Dion himself was aware that Christian interference, and not that of an +Egyptian, saved the day. "Dion knew," he declares, "that there existed +a legion called The Thundering Legion, which name was given it for no +other reason than for what came to pass in this war," and that this +legion was composed of soldiers from Militene who were all professed +Christians. "During the battle," continues Xiphilinus, "the chief of the +Pretonians, had set at Marcus Antoninus, who was in great perplexity at +the turn events were taking, representing to him that there was nothing +the people called Christians could not obtain by their prayers, and +that among his forces was a troop composed wholly of followers of that +religion. Rejoiced at this news, Marcus Antoninus demanded of these +soldiers that they should pray to their god, who granted their petition +on the instant, sent lightning among the enemy and consoled the Romans +with rain. Struck by this wonderful success, the emperor honored the +Christians in an edict and named their legion The Thundering. It is even +asserted that a letter existed by Marcus Antoninus on this subject. +The pagans well knew that the company was called The Thunderers, having +attested the fact themselves, but they revealed nothing of the occasion +on which the leader received the name."(1) + +Peculiar interest attaches to this narrative as illustrating both +credulousness as to matters of fact and pseudo-scientific explanation +of alleged facts. The modern interpreter may suppose that a violent +thunderstorm came up during the course of a battle between the Romans +and the so-called barbarians, and that owing to the local character of +the storm, or a chance discharge of lightning, the barbarians +suffered more than their opponents. We may well question whether the +philosophical emperor himself put any other interpretation than this +upon the incident. But, on the other hand, we need not doubt that the +major part of his soldiers would very readily accept such an explanation +as that given by Dion Cassius, just as most readers of a few centuries +later would accept the explanation of Xiphilinus. It is well to bear +this thought in mind in considering the static period of science upon +which we are entering. We shall perhaps best understand this period, and +its seeming retrogressions, if we suppose that the average man of the +Middle Ages was no more credulous, no more superstitious, than the +average Roman of an earlier period or than the average Greek; though the +precise complexion of his credulity had changed under the influence of +Oriental ideas, as we have just seen illustrated by the narrative of +Xiphilinus. + + + + +APPENDIX + +REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES + + + +CHAPTER I. PREHISTORIC SCIENCE + +Length of the Prehistoric Period.--It is of course quite impossible to +reduce the prehistoric period to any definite number of years. There +are, however, numerous bits of evidence that enable an anthropologist to +make rough estimates as to the relative lengths of the different periods +into which prehistoric time is divided. Gabriel de Mortillet, one of the +most industrious students of prehistoric archaeology, ventured to give +a tentative estimate as to the numbers of years involved in each +period. He of course claimed for this nothing more than the value of a +scientific guess. It is, however, a guess based on a very careful study +of all data at present available. Mortillet divides the prehistoric +period, as a whole, into four epochs. The first of these is the +preglacial, which he estimates as comprising seventy-eight thousand +years; the second is the glacial, covering one hundred thousand years; +then follows what he terms the Solutreen, which numbers eleven thousand +years; and, finally, the Magdalenien, comprising thirty-three thousand +years. This gives, for the prehistoric period proper, a term of about +two hundred and twenty-two thousand years. Add to this perhaps twelve +thousand years ushering in the civilization of Egypt, and the six +thousand years of stable, sure chronology of the historical period, and +we have something like two hundred and thirty thousand or two hundred +and forty thousand years as the age of man. + +"These figures," says Mortillet, "are certainly not exaggerated. It is +even probable that they are below the truth. Constantly new discoveries +are being made that tend to remove farther back the date of man's +appearance." We see, then, according to this estimate, that about a +quarter of a million years have elapsed since man evolved to a state +that could properly be called human. This guess is as good as another, +and it may advantageously be kept in mind, as it will enable us all +along to understand better than we might otherwise be able to do the +tremendous force of certain prejudices and preconceptions which recent +man inherited from his prehistoric ancestor. Ideas which had passed +current as unquestioned truths for one hundred thousand years or so are +not easily cast aside. + +In going back, in imagination, to the beginning of the prehistoric +period, we must of course reflect, in accordance with modern ideas on +the subject, that there was no year, no millennium even, when it could +be said expressly: "This being was hitherto a primate, he is now a man." +The transition period must have been enormously long, and the changes +from generation to generation, even from century to century, must have +been very slight. In speaking of the extent of the age of man this must +be borne in mind: it must be recalled that, even if the period were not +vague for other reasons, the vagueness of its beginning must make it +indeterminate. + +Bibliographical Notes.--A great mass of literature has been produced in +recent years dealing with various phases of the history of prehistoric +man. No single work known to the writer deals comprehensively with the +scientific attainments of early man; indeed, the subject is usually +ignored, except where practical phases of the mechanical arts are +in question. But of course any attempt to consider the condition of +primitive man talies into account, by inference at least, his knowledge +and attainments. Therefore, most works on anthropology, ethnology, and +primitive culture may be expected to throw some light on our present +subject. Works dealing with the social and mental conditions of existing +savages are also of importance, since it is now an accepted belief that +the ancestors of civilized races evolved along similar lines and passed +through corresponding stages of nascent culture. Herbert Spencer's +Descriptive Sociology presents an unequalled mass of facts regarding +existing primitive races, but, unfortunately, its inartistic method +of arrangement makes it repellent to the general reader. E. B. Tyler's +Primitive Culture and Anthropology; Lord Avebury's Prehistoric Times, +The Origin of Civilization, and The Primitive Condition of Man; W. +Boyd Dawkin's Cave-Hunting and Early Man in Britain; and Edward Clodd's +Childhood of the World and Story of Primitive Man are deservedly +popular. Paul Topinard's Elements d'Anthropologie Generale is one of the +best-known and most comprehensive French works on the technical phases +of anthropology; but Mortillet's Le Prehistorique has a more popular +interest, owing to its chapters on primitive industries, though this +work also contains much that is rather technical. Among periodicals, the +Revue de l'Ecole d'Anthropologie de Paris, published by the professors, +treats of all phases of anthropology, and the American Anthropologist, +edited by F. W. Hodge for the American Anthropological Association, and +intended as "a medium of communication between students of all branches +of anthropology," contains much that is of interest from the present +stand-point. The last-named journal devotes a good deal of space to +Indian languages. + + +CHAPTER II. EGYPTIAN SCIENCE + +1 (p. 34). Sir J. Norman Lockyer, The Dawn of Astronomy; a study of the +temple worship and mythology of the ancient Egyptians, London, 1894. + +2 (p. 43). G. Maspero, Histoire Ancie-nne des Peuples de l'Orient +Classique, Paris, 1895. Translated as (1) The Dawn of Civilization, (2) +The Struggle of the Nations, (3) The Passing of the Empires, 3 vols., +London and New York, 1894-1900. Professor Maspero is one of the most +famous of living Orientalists. His most important special studies +have to do with Egyptology, but his writings cover the entire field of +Oriental antiquity. He is a notable stylist, and his works are at once +readable and authoritative. + +3 (p. 44). Adolf Erman, Life in Ancient Egypt, London, 1894, p. +352. (Translated from the original German work entitled Aegypten +und aegyptisches Leben in Alterthum, Tilbigen, 1887.) An altogether +admirable work, full of interest for the general reader, though based on +the most erudite studies. + +4 (p. 47). Erman, op. cit., pp. 356, 357. + +5 (p. 48). Erman, op. cit., p. 357. The work on Egyptian medicine here +referred to is Georg Ebers' edition of an Egyptian document discovered +by the explorer whose name it bears. It remains the most important +source of our knowledge of Egyptian medicine. As mentioned in the text, +this document dates from the eighteenth dynasty--that is to say, from +about the fifteenth or sixteenth century, B.C., a relatively late period +of Egyptian history. + +6 (p. 49). Erman, op. cit., p. 357. + +7 (p. 50). The History of Herodotus, pp. 85-90. There are numerous +translations of the famous work of the "father of history," one of the +most recent and authoritative being that of G. C. Macaulay, M.A., in two +volumes, Macmillan & Co., London and New York, 1890. + +8 (p. 50). The Historical Library of Diodorus the Sicilian, London, +1700. This most famous of ancient world histories is difficult to obtain +in an English version. The most recently published translation known to +the writer is that of G. Booth, London, 1814. + +9 (p. 51). Erman, op. cit., p. 357. + +10 (p. 52). The Papyrus Rhind is a sort of mathematical hand-book of the +ancient Egyptians; it was made in the time of the Hyksos Kings (about +2000 B.C.), but is a copy of an older book. It is now preserved in the +British Museum. + +The most accessible recent sources of information as to the social +conditions of the ancient Egyptians are the works of Maspero and Erman, +above mentioned; and the various publications of W. M. Flinders Petrie, +The Pyramids and Temples of Gizeh, London, 1883; Tanis I., London, 1885; +Tanis H., Nebesheh, and Defe-nnel, London, 1887; Ten Years' Diggings, +London, 1892; Syria and Egypt from the Tel-el-Amar-na Letters, London, +1898, etc. The various works of Professor Petrie, recording his +explorations from year to year, give the fullest available insight into +Egyptian archaeology. + +CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + +1 (p. 57). The Medes. Some difference of opinion exists among historians +as to the exact ethnic relations of the conquerors; the precise date of +the fall of Nineveh is also in doubt. + +2 (p. 57). Darius. The familiar Hebrew narrative ascribes the first +Persian conquest of Babylon to Darius, but inscriptions of Cyrus and of +Nabonidus, the Babylonian king, make it certain that Cyrus was the real +conqueror. These inscriptions are preserved on cylinders of baked clay, +of the type made familiar by the excavation of the past fifty years, and +they are invaluable historical documents. + +3 (p. 58). Berosus. The fragments of Berosus have been translated by L. +P. Cory, and included in his Ancient Fragments of Phenician, Chaldean, +Egyptian, and Other Writers, London, 1826, second edition, 1832. + +4 (p. 58). Chaldean learning. Recent writers reserve the name Chaldean +for the later period of Babylonian history--the time when the Greeks +came in contact with the Mesopotamians--in contradistinction to the +earlier periods which are revealed to us by the archaeological records. + +5 (p. 59) King Sargon of Agade. The date given for this early king must +not be accepted as absolute; but it is probably approximately correct. + +6 (p. 59). Nippur. See the account of the early expeditions as recorded +by the director, Dr. John P. Peters, Nippur, or explorations and +adventures, etc., New York and London, 1897. + +7 (p. 62). Fritz Hommel, Geschichte Babyloniens und Assyriens, Berlin, +1885. + +8 (p. 63). R. Campbell Thompson, Reports of the Magicians and +Astrologers of Nineveh and Babylon, London, 1900, p. xix. + +9 (p. 64). George Smith, The Assyrian Canon, p. 21. + +10 (p. 64). Thompson, op. cit., p. xix. + +11 (p. 65). Thompson, op. cit., p. 2. + +12 (p. 67). Thompson, op. cit., p. xvi. + +13 (p. 68). Sextus Empiricus, author of Adversus Mathematicos, lived +about 200 A.D. + +14 (p. 68). R. Campbell Thompson, op. cit., p. xxiv. + +15 (p. 72). Records of the Past (editor, Samuel Birch), Vol. III., p. +139. + +16 (p. 72). Ibid., Vol. V., p. 16. + +17 (p. 72). Quoted in Records of the Past, Vol. III., p. 143, from the +Translations of the Society of Biblical Archeology, vol. II., p. 58. + +18 (p. 73). Records of the Past, vol. L, p. 131. + +19 (p. 73). Ibid., vol. V., p. 171. + +20 (p. 74). Ibid., vol. V., p. 169. + +21 (p. 74). Joachim Menant, La Bibliotheque du Palais de Ninive, Paris, +1880. + +22 (p. 76). Code of Khamurabi. This famous inscription is on a block of +black diorite nearly eight feet in height. It was discovered at Susa by +the French expedition under M. de Morgan, in December, 1902. We quote +the translation given in The Historians' History of the World, edited by +Henry Smith Williams, London and New York, 1904, Vol. I, p. 510. + +23 (p. 77). The Historical Library of Diodorus Siculus, p. 519. + +24 (p. 82). George S. Goodspeed, Ph.D., History of the Babylonians and +Assyrians, New York, 1902. + +25 (p. 82). George Rawlinson, Great Oriental Monarchies, (second +edition, London, 1871), Vol. III., pp. 75 ff. + +Of the books mentioned above, that of Hommel is particularly full in +reference to culture development; Goodspeed's small volume gives an +excellent condensed account; the original documents as translated in +the various volumes of Records of the Past are full of interest; and +Menant's little book is altogether admirable. The work of excavation +is still going on in old Babylonia, and newly discovered texts add +from time to time to our knowledge, but A. H. Layard's Nineveh and its +Remains (London, 1849) still has importance as a record of the most +important early discoveries. The general histories of Antiquity of +Duncker, Lenormant, Maspero, and Meyer give full treatment of Babylonian +and Assyrian development. Special histories of Babylonia and Assyria, +in addition to these named above, are Tiele's Babylonisch-Assyrische +Geschichte (Zwei Tiele, Gotha, 1886-1888); Winckler's Geschichte +Babyloniens und Assyriens (Berlin, 1885-1888), and Rogers' History of +Babylonia and Assyria, New York and London, 1900, the last of which, +however, deals almost exclusively with political history. Certain phases +of science, particularly with reference to chronology and cosmology, are +treated by Edward Meyer (Geschichte des Alterthum, Vol. I., Stuttgart, +1884), and by P. Jensen (Die Kosmologie der Babylonier, Strassburg, +1890), but no comprehensive specific treatment of the subject in its +entirety has yet been attempted. + +CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + +1 (p. 87). Vicomte E. de Rouge, Memoire sur l'Origine Egyptienne de +l'Alphabet Phinicien, Paris, 1874. + +2 (p. 88). See the various publications of Mr. Arthur Evans. + +3 (p. 80). Aztec and Maya writing. These pictographs are still in +the main undecipherable, and opinions differ as to the exact stage of +development which they represent. + +4 (p. 90). E. A. Wallace Budge's First Steps in Egyptian, London, 1895, +is an excellent elementary work on the Egyptian writing. Professor +Erman's Egyptian Grammar, London, 1894, is the work of perhaps the +foremost living Egyptologist. + +5 (P. 93). Extant examples of Babylonian and Assyrian writing give +opportunity to compare earlier and later systems, so the fact of +evolution from the pictorial to the phonetic system rests on something +more than mere theory. + +6 (p. 96). Friedrich Delitzsch, Assyrischc Lesestucke mit grammatischen +Tabellen und vollstdndigem Glossar einfiihrung in die assyrische und +babylonische Keilschrift-litteratur bis hinauf zu Hammurabi, Leipzig, +1900. + +7 (p. 97). It does not appear that the Babylonians thcmselves ever +gave up the old system of writing, so long as they retained political +autonomy. + +8 (p. 101). See Isaac Taylor's History of the Alphabet; an Account of +the origin and Development of Letters, new edition, 2 vols., London, +1899. + +For facsimiles of the various scripts, see Henry Smith Williams' History +of the Art Of Writing, 4 vols, New York and London, 1902-1903. + +CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + +1 (p. III). Anaximander, as recorded by Plutarch, vol. VIII-. See Arthur +Fairbanks'First Philosophers of Greece: an Edition and Translation of +the Remaining Fragments of the Pre-Socratic Philosophers, together with +a Translation of the more Important Accounts of their Opinions Contained +in the Early Epitomcs of their Works, London, 1898. This highly +scholarly and extremely useful book contains the Greek text as well as +translations. + +CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +1 (p. 117). George Henry Lewes, A Biographical History of Philosophy +from its Origin in Greece down to the Present Day, enlarged edition, New +York, 1888, p. 17. + +2 (p. 121). Diogenes Laertius, The Lives and Opinions of Eminent +Philosophers, C. D. Yonge's translation, London, 1853, VIII., p. 153. + +3 (p. 121). Alexander, Successions of Philosophers. + +4 (p. 122). "All over its centre." Presumably this is intended to refer +to the entire equatorial region. + +5 (p. 125). Laertius, op. cit., pp. 348-351. + +6 (p. 128). Arthur Fairbanks, The First Philosophers of Greece London, +1898, pp. 67-717. + +7 (p. 129). Ibid., p. 838. + +8 (p. 130). Ibid., p. 109. + +9 (p. 130). Heinrich Ritter, The History of Ancient Philosophy, +translated from the German by A. J. W. Morrison, 4 vols., London, 1838, +vol, I., p. 463. + +10 (p. 131). Ibid., p. 465. + +11 (p. 132). George Henry Lewes, op. cit., p. 81. + +12 (p. 135). Fairbanks, op. cit., p. 201. + +13 (p. 136). Ibid., P. 234. + +14 (p. 137). Ibid., p. 189. + +15 (p. 137). Ibid., P. 220. + +16 (p. 138). Ibid., p. 189. + +17 (p. 138). Ibid., p. 191. + +CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +1 (p. 150). Theodor Gomperz, Greek Thinkers: a History of Ancient +Philosophy (translated from the German by Laurie Magnes), New York, 190 +1, pp. 220, 221. + +2 (p. 153). Aristotle's Treatise on Respiration, ch. ii. + +3 (p. 159). Fairbanks' translation of the fragments of Anaxagoras, in +The First Philosophers of Greece, pp. 239-243. + +CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + +1 (p. 180). Alfred William Bern, The Philosophy of Greece Considered in +Relation to the Character and History of its People, London, 1898, p. +186. + +2 (p. 183). Aristotle, quoted in William Whewell's History of the +Inductive Sciences (second edition, London, 1847), Vol. II., p. 161. + +CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + +1 (p. 195). Tertullian's Apologeticus. + +2 (p. 205). We quote the quaint old translation of North, printed in +1657. + +CHAPTER X. SCIENCE OF THE ROMAN PERIOD + +1 (p. 258). The Geography of Strabo, translated by H. C. Hamilton and W. +Falconer, 3 vols., London, 1857, Vol. I, pp. 19, 20. + +2 (p. 260). Ibid., p. 154. + +3 (p. 263). Ibid., pp. 169, 170. + +4 (p. 264) Ibid., pp. 166, 167. + +5 (p. 271). K. 0. Miller and John W. Donaldson, The History of the +Literature of Greece, 3 vols., London, Vol. III., p. 268. + + +6 (p. 276). E. T. Withington, Medical History fron., the Earliest Times, +London, 1894, p. 118. + +7 (p. 281). Ibid. + +8 (p. 281). Johann Hermann Bass, History of Medicine, New York, 1889. + +CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +(p. 298). Dion Cassius, as preserved by Xiphilinus. Our extract is +quoted from the translation given in The Historians' History of the +World (edited by Henry Smith Williams), 25 vols., London and New York, +1904, Vol. VI., p. 297 ff. + + +(For further bibliographical notes, the reader is referred to the +Appendix of volume V.) + + + + + + +End of the Project Gutenberg EBook of A History of Science, Volume 1(of 5), by +Henry Smith Williams + +*** END OF THIS PROJECT GUTENBERG EBOOK HISTORY OF SCIENCE, V1 *** + +***** This file should be named 1705.txt or 1705.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/1/7/0/1705/ + +Produced by Charles Keller + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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WILLIAMS, M.D. + +IN FIVE VOLUMES +VOLUME I. + +THE BEGINNINGS OF SCIENCE + + + + +BOOK I. + +CONTENTS + +CHAPTER I. PREHISTORIC SCIENCE + +CHAPTER II. EGYPTIAN SCIENCE + +CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + +CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + +CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + +CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + +CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC +PERIOD + +CHAPTER X. SCIENCE OF THE ROMAN PERIOD + +CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +APPENDIX + + +A HISTORY OF SCIENCE + +BOOK I + +Should the story that is about to be unfolded be found to lack +interest, the writers must stand convicted of unpardonable lack +of art. Nothing but dulness in the telling could mar the story, +for in itself it is the record of the growth of those ideas that +have made our race and its civilization what they are; of ideas +instinct with human interest, vital with meaning for our race; +fundamental in their influence on human development; part and +parcel of the mechanism of human thought on the one hand, and of +practical civilization on the other. Such a phrase as +"fundamental principles" may seem at first thought a hard saying, +but the idea it implies is less repellent than the phrase itself, +for the fundamental principles in question are so closely linked +with the present interests of every one of us that they lie +within the grasp of every average man and woman--nay, of every +well-developed boy and girl. These principles are not merely the +stepping-stones to culture, the prerequisites of knowledge--they +are, in themselves, an essential part of the knowledge of every +cultivated person. + +It is our task, not merely to show what these principles are, but +to point out how they have been discovered by our predecessors. +We shall trace the growth of these ideas from their first vague +beginnings. We shall see how vagueness of thought gave way to +precision; how a general truth, once grasped and formulated, was +found to be a stepping-stone to other truths. We shall see that +there are no isolated facts, no isolated principles, in nature; +that each part of our story is linked by indissoluble bands with +that which goes before, and with that which comes after. For the +most part the discovery of this principle or that in a given +sequence is no accident. Galileo and Keppler must precede Newton. +Cuvier and Lyall must come before Darwin;--Which, after all, is +no more than saying that in our Temple of Science, as in any +other piece of architecture, the foundation must precede the +superstructure. + +We shall best understand our story of the growth of science if we +think of each new principle as a stepping-stone which must fit +into its own particular niche; and if we reflect that the entire +structure of modern civilization would be different from what it +is, and less perfect than it is, had not that particular +stepping-stone been found and shaped and placed in position. +Taken as a whole, our stepping-stones lead us up and up towards +the alluring heights of an acropolis of knowledge, on which +stands the Temple of Modern Science. The story of the building of +this wonderful structure is in itself fascinating and beautiful. + + + +I. PREHISTORIC SCIENCE + +To speak of a prehistoric science may seem like a contradiction +of terms. The word prehistoric seems to imply barbarism, while +science, clearly enough, seems the outgrowth of civilization; but +rightly considered, there is no contradiction. For, on the one +hand, man had ceased to be a barbarian long before the beginning +of what we call the historical period; and, on the other hand, +science, of a kind, is no less a precursor and a cause of +civilization than it is a consequent. To get this clearly in +mind, we must ask ourselves: What, then, is science? The word +runs glibly enough upon the tongue of our every-day speech, but +it is not often, perhaps, that they who use it habitually ask +themselves just what it means. Yet the answer is not difficult. A +little attention will show that science, as the word is commonly +used, implies these things: first, the gathering of knowledge +through observation; second, the classification of such +knowledge, and through this classification, the elaboration of +general ideas or principles. In the familiar definition of +Herbert Spencer, science is organized knowledge. + +Now it is patent enough, at first glance, that the veriest savage +must have been an observer of the phenomena of nature. But it may +not be so obvious that he must also have been a classifier of his +observations--an organizer of knowledge. Yet the more we consider +the case, the more clear it will become that the two methods are +too closely linked together to be dissevered. To observe outside +phenomena is not more inherent in the nature of the mind than to +draw inferences from these phenomena. A deer passing through the +forest scents the ground and detects a certain odor. A sequence +of ideas is generated in the mind of the deer. Nothing in the +deer's experience can produce that odor but a wolf; therefore the +scientific inference is drawn that wolves have passed that way. +But it is a part of the deer's scientific knowledge, based on +previous experience, individual and racial; that wolves are +dangerous beasts, and so, combining direct observation in the +present with the application of a general principle based on past +experience, the deer reaches the very logical conclusion that it +may wisely turn about and run in another direction. All this +implies, essentially, a comprehension and use of scientific +principles; and, strange as it seems to speak of a deer as +possessing scientific knowledge, yet there is really no absurdity +in the statement. The deer does possess scientific knowledge; +knowledge differing in degree only, not in kind, from the +knowledge of a Newton. Nor is the animal, within the range of its +intelligence, less logical, less scientific in the application of +that knowledge, than is the man. The animal that could not make +accurate scientific observations of its surroundings, and deduce +accurate scientific conclusions from them, would soon pay the +penalty of its lack of logic. + +What is true of man's precursors in the animal scale is, of +course, true in a wider and fuller sense of man himself at the +very lowest stage of his development. Ages before the time which +the limitations of our knowledge force us to speak of as the dawn +of history, man had reached a high stage of development. As a +social being, he had developed all the elements of a primitive +civilization. If, for convenience of classification, we speak of +his state as savage, or barbaric, we use terms which, after all, +are relative, and which do not shut off our primitive ancestors +from a tolerably close association with our own ideals. We know +that, even in the Stone Age, man had learned how to domesticate +animals and make them useful to him, and that he had also learned +to cultivate the soil. Later on, doubtless by slow and painful +stages, he attained those wonderful elements of knowledge that +enabled him to smelt metals and to produce implements of bronze, +and then of iron. Even in the Stone Age he was a mechanic of +marvellous skill, as any one of to-day may satisfy himself by +attempting to duplicate such an implement as a chipped +arrow-head. And a barbarian who could fashion an axe or a knife +of bronze had certainly gone far in his knowledge of scientific +principles and their practical application. The practical +application was, doubtless, the only thought that our primitive +ancestor had in mind; quite probably the question as to +principles that might be involved troubled him not at all. Yet, +in spite of himself, he knew certain rudimentary principles of +science, even though he did not formulate them. + +Let us inquire what some of these principles are. Such an inquiry +will, as it were, clear the ground for our structure of science. +It will show the plane of knowledge on which historical +investigation begins. Incidentally, perhaps, it will reveal to us +unsuspected affinities between ourselves and our remote ancestor. +Without attempting anything like a full analysis, we may note in +passing, not merely what primitive man knew, but what he did not +know; that at least a vague notion may be gained of the field for +scientific research that lay open for historic man to cultivate. + + +It must be understood that the knowledge of primitive man, as we +are about to outline it, is inferential. We cannot trace the +development of these principles, much less can we say who +discovered them. Some of them, as already suggested, are man's +heritage from non-human ancestors. Others can only have been +grasped by him after he had reached a relatively high stage of +human development. But all the principles here listed must surely +have been parts of our primitive ancestor's knowledge before +those earliest days of Egyptian and Babylonian civilization, the +records of which constitute our first introduction to the +so-called historical period. Taken somewhat in the order of their +probable discovery, the scientific ideas of primitive man may be +roughly listed as follows: + +1. Primitive man must have conceived that the earth is flat and +of limitless extent. By this it is not meant to imply that he had +a distinct conception of infinity, but, for that matter, it +cannot be said that any one to-day has a conception of infinity +that could be called definite. But, reasoning from experience and +the reports of travellers, there was nothing to suggest to early +man the limit of the earth. He did, indeed, find in his +wanderings, that changed climatic conditions barred him from +farther progress; but beyond the farthest reaches of his +migrations, the seemingly flat land-surfaces and water-surfaces +stretched away unbroken and, to all appearances, without end. It +would require a reach of the philosophical imagination to +conceive a limit to the earth, and while such imaginings may have +been current in the prehistoric period, we can have no proof of +them, and we may well postpone consideration of man's early +dreamings as to the shape of the earth until we enter the +historical epoch where we stand on firm ground. + +2. Primitive man must, from a very early period, have observed +that the sun gives heat and light, and that the moon and stars +seem to give light only and no heat. It required but a slight +extension of this observation to note that the changing phases of +the seasons were associated with the seeming approach and +recession of the sun. This observation, however, could not have +been made until man had migrated from the tropical regions, and +had reached a stage of mechanical development enabling him to +live in subtropical or temperate zones. Even then it is +conceivable that a long period must have elapsed before a direct +causal relation was felt to exist between the shifting of the sun +and the shifting of the seasons; because, as every one knows, the +periods of greatest heat in summer and greatest cold in winter +usually come some weeks after the time of the solstices. Yet, the +fact that these extremes of temperature are associated in some +way with the change of the sun's place in the heavens must, in +time, have impressed itself upon even a rudimentary intelligence. +It is hardly necessary to add that this is not meant to imply any +definite knowledge of the real meaning of, the seeming +oscillations of the sun. We shall see that, even at a relatively +late period, the vaguest notions were still in vogue as to the +cause of the sun's changes of position. + +That the sun, moon, and stars move across the heavens must +obviously have been among the earliest scientific observations. +It must not be inferred, however, that this observation implied a +necessary conception of the complete revolution of these bodies +about the earth. It is unnecessary to speculate here as to how +the primitive intelligence conceived the transfer of the sun from +the western to the eastern horizon, to be effected each night, +for we shall have occasion to examine some historical +speculations regarding this phenomenon. We may assume, however, +that the idea of the transfer of the heavenly bodies beneath the +earth (whatever the conception as to the form of that body) must +early have presented itself. + +It required a relatively high development of the observing +faculties, yet a development which man must have attained ages +before the historical period, to note that the moon has a +secondary motion, which leads it to shift its relative position +in the heavens, as regards the stars; that the stars themselves, +on the other hand, keep a fixed relation as regards one another, +with the notable exception of two or three of the most brilliant +members of the galaxy, the latter being the bodies which came to +be known finally as planets, or wandering stars. The wandering +propensities of such brilliant bodies as Jupiter and Venus cannot +well have escaped detection. We may safely assume, however, that +these anomalous motions of the moon and planets found no +explanation that could be called scientific until a relatively +late period. + +3. Turning from the heavens to the earth, and ignoring such +primitive observations as that of the distinction between land +and water, we may note that there was one great scientific law +which must have forced itself upon the attention of primitive +man. This is the law of universal terrestrial gravitation. The +word gravitation suggests the name of Newton, and it may excite +surprise to hear a knowledge of gravitation ascribed to men who +preceded that philosopher by, say, twenty-five or fifty thousand +years. Yet the slightest consideration of the facts will make it +clear that the great central law that all heavy bodies fall +directly towards the earth, cannot have escaped the attention of +the most primitive intelligence. The arboreal habits of our +primitive ancestors gave opportunities for constant observation +of the practicalities of this law. And, so soon as man had +developed the mental capacity to formulate ideas, one of the +earliest ideas must have been the conception, however vaguely +phrased in words, that all unsupported bodies fall towards the +earth. The same phenomenon being observed to operate on +water-surfaces, and no alteration being observed in its operation +in different portions of man's habitat, the most primitive +wanderer must have come to have full faith in the universal +action of the observed law of gravitation. Indeed, it is +inconceivable that he can have imagined a place on the earth +where this law does not operate. On the other hand, of course, he +never grasped the conception of the operation of this law beyond +the close proximity of the earth. To extend the reach of +gravitation out to the moon and to the stars, including within +its compass every particle of matter in the universe, was the +work of Newton, as we shall see in due course. Meantime we shall +better understand that work if we recall that the mere local fact +of terrestrial gravitation has been the familiar knowledge of all +generations of men. It may further help to connect us in sympathy +with our primeval ancestor if we recall that in the attempt to +explain this fact of terrestrial gravitation Newton made no +advance, and we of to-day are scarcely more enlightened than the +man of the Stone Age. Like the man of the Stone Age, we know that +an arrow shot into the sky falls back to the earth. We can +calculate, as he could not do, the arc it will describe and the +exact speed of its fall; but as to why it returns to earth at +all, the greatest philosopher of to-day is almost as much in the +dark as was the first primitive bowman that ever made the +experiment. + +Other physical facts going to make up an elementary science of +mechanics, that were demonstratively known to prehistoric man, +were such as these: the rigidity of solids and the mobility of +liquids; the fact that changes of temperature transform solids to +liquids and vice versa--that heat, for example, melts copper and +even iron, and that cold congeals water; and the fact that +friction, as illustrated in the rubbing together of two sticks, +may produce heat enough to cause a fire. The rationale of this +last experiment did not receive an explanation until about the +beginning of the nineteenth century of our own era. But the +experimental fact was so well known to prehistoric man that he +employed this method, as various savage tribes employ it to this +day, for the altogether practical purpose of making a fire; just +as he employed his practical knowledge of the mutability of +solids and liquids in smelting ores, in alloying copper with tin +to make bronze, and in casting this alloy in molds to make +various implements and weapons. Here, then, were the germs of an +elementary science of physics. Meanwhile such observations as +that of the solution of salt in water may be considered as giving +a first lesson in chemistry, but beyond such altogether +rudimentary conceptions chemical knowledge could not have +gone--unless, indeed, the practical observation of the effects of +fire be included; nor can this well be overlooked, since scarcely +another single line of practical observation had a more direct +influence in promoting the progress of man towards the heights of +civilization. + +4. In the field of what we now speak of as biological knowledge, +primitive man had obviously the widest opportunity for practical +observation. We can hardly doubt that man attained, at an early +day, to that conception of identity and of difference which Plato +places at the head of his metaphysical system. We shall urge +presently that it is precisely such general ideas as these that +were man's earliest inductions from observation, and hence that +came to seem the most universal and "innate" ideas of his +mentality. It is quite inconceivable, for example, that even the +most rudimentary intelligence that could be called human could +fail to discriminate between living things and, let us say, the +rocks of the earth. The most primitive intelligence, then, must +have made a tacit classification of the natural objects about it +into the grand divisions of animate and inanimate nature. +Doubtless the nascent scientist may have imagined life animating +many bodies that we should call inanimate--such as the sun, +wandering planets, the winds, and lightning; and, on the other +hand, he may quite likely have relegated such objects as trees to +the ranks of the non-living; but that he recognized a fundamental +distinction between, let us say, a wolf and a granite bowlder we +cannot well doubt. A step beyond this--a step, however, that may +have required centuries or millenniums in the taking--must have +carried man to a plane of intelligence from which a primitive +Aristotle or Linnaeus was enabled to note differences and +resemblances connoting such groups of things as fishes, birds, +and furry beasts. This conception, to be sure, is an abstraction +of a relatively high order. We know that there are savage races +to-day whose language contains no word for such an abstraction as +bird or tree. We are bound to believe, then, that there were long +ages of human progress during which the highest man had attained +no such stage of abstraction; but, on the other hand, it is +equally little in question that this degree of mental development +had been attained long before the opening of our historical +period. The primeval man, then, whose scientific knowledge we are +attempting to predicate, had become, through his conception of +fishes, birds, and hairy animals as separate classes, a +scientific zoologist of relatively high attainments. + +In the practical field of medical knowledge, a certain stage of +development must have been reached at a very early day. Even +animals pick and choose among the vegetables about them, and at +times seek out certain herbs quite different from their ordinary +food, practising a sort of instinctive therapeutics. The cat's +fondness for catnip is a case in point. The most primitive man, +then, must have inherited a racial or instinctive knowledge of +the medicinal effects of certain herbs; in particular he must +have had such elementary knowledge of toxicology as would enable +him to avoid eating certain poisonous berries. Perhaps, indeed, +we are placing the effect before the cause to some extent; for, +after all, the animal system possesses marvellous powers of +adaption, and there is perhaps hardly any poisonous vegetable +which man might not have learned to eat without deleterious +effect, provided the experiment were made gradually. To a certain +extent, then, the observed poisonous effects of numerous plants +upon the human system are to be explained by the fact that our +ancestors have avoided this particular vegetable. Certain fruits +and berries might have come to have been a part of man's diet, +had they grown in the regions he inhabited at an early day, which +now are poisonous to his system. This thought, however, carries +us too far afield. For practical purposes, it suffices that +certain roots, leaves, and fruits possess principles that are +poisonous to the human system, and that unless man had learned in +some way to avoid these, our race must have come to disaster. In +point of fact, he did learn to avoid them; and such evidence +implied, as has been said, an elementary knowledge of toxicology. + +Coupled with this knowledge of things dangerous to the human +system, there must have grown up, at a very early day, a belief +in the remedial character of various vegetables as agents to +combat disease. Here, of course, was a rudimentary therapeutics, +a crude principle of an empirical art of medicine. As just +suggested, the lower order of animals have an instinctive +knowledge that enables them to seek out remedial herbs (though we +probably exaggerate the extent of this instinctive knowledge); +and if this be true, man must have inherited from his prehuman +ancestors this instinct along with the others. That he extended +this knowledge through observation and practice, and came early +to make extensive use of drugs in the treatment of disease, is +placed beyond cavil through the observation of the various +existing barbaric tribes, nearly all of whom practice elaborate +systems of therapeutics. We shall have occasion to see that even +within historic times the particular therapeutic measures +employed were often crude, and, as we are accustomed to say, +unscientific; but even the crudest of them are really based upon +scientific principles, inasmuch as their application implies the +deduction of principles of action from previous observations. +Certain drugs are applied to appease certain symptoms of disease +because in the belief of the medicine-man such drugs have proved +beneficial in previous similar cases. + +All this, however, implies an appreciation of the fact that man +is subject to "natural" diseases, and that if these diseases are +not combated, death may result. But it should be understood that +the earliest man probably had no such conception as this. +Throughout all the ages of early development, what we call +"natural" disease and "natural" death meant the onslaught of a +tangible enemy. A study of this question leads us to some very +curious inferences. The more we look into the matter the more the +thought forces itself home to us that the idea of natural death, +as we now conceive it, came to primitive man as a relatively late +scientific induction. This thought seems almost startling, so +axiomatic has the conception "man is mortal" come to appear. Yet +a study of the ideas of existing savages, combined with our +knowledge of the point of view from which historical peoples +regard disease, make it more probable that the primitive +conception of human life did not include the idea of necessary +death. We are told that the Australian savage who falls from a +tree and breaks his neck is not regarded as having met a natural +death, but as having been the victim of the magical practices of +the "medicine-man" of some neighboring tribe. Similarly, we shall +find that the Egyptian and the Babylonian of the early historical +period conceived illness as being almost invariably the result of +the machinations of an enemy. One need but recall the +superstitious observances of the Middle Ages, and the yet more +recent belief in witchcraft, to realize how generally disease has +been personified as a malicious agent invoked by an unfriendly +mind. Indeed, the phraseology of our present-day speech is still +reminiscent of this; as when, for example, we speak of an "attack +of fever," and the like. + +When, following out this idea, we picture to ourselves the +conditions under which primitive man lived, it will be evident at +once how relatively infrequent must have been his observation of +what we usually term natural death. His world was a world of +strife; he lived by the chase; he saw animals kill one another; +he witnessed the death of his own fellows at the hands of +enemies. Naturally enough, then, when a member of his family was +"struck down" by invisible agents, he ascribed this death also to +violence, even though the offensive agent was concealed. +Moreover, having very little idea of the lapse of time--being +quite unaccustomed, that is, to reckon events from any fixed +era--primitive man cannot have gained at once a clear conception +of age as applied to his fellows. Until a relatively late stage +of development made tribal life possible, it cannot have been +usual for man to have knowledge of his grandparents; as a rule he +did not know his own parents after he had passed the adolescent +stage and had been turned out upon the world to care for himself. +If, then, certain of his fellow-beings showed those evidences of +infirmity which we ascribe to age, it did not necessarily follow +that he saw any association between such infirmities and the +length of time which those persons had lived. The very fact that +some barbaric nations retain the custom of killing the aged and +infirm, in itself suggests the possibility that this custom arose +before a clear conception had been attained that such drags upon +the community would be removed presently in the natural order of +things. To a person who had no clear conception of the lapse of +time and no preconception as to the limited period of man's life, +the infirmities of age might very naturally be ascribed to the +repeated attacks of those inimical powers which were understood +sooner or later to carry off most members of the race. And +coupled with this thought would go the conception that inasmuch +as some people through luck had escaped the vengeance of all +their enemies for long periods, these same individuals might +continue to escape for indefinite periods of the future. There +were no written records to tell primeval man of events of long +ago. He lived in the present, and his sweep of ideas scarcely +carried him back beyond the limits of his individual memory. But +memory is observed to be fallacious. It must early have been +noted that some people recalled events which other participants +in them had quite forgotten, and it may readily enough have been +inferred that those members of the tribe who spoke of events +which others could not recall were merely the ones who were +gifted with the best memories. If these reached a period when +their memories became vague, it did not follow that their +recollections had carried them back to the beginnings of their +lives. Indeed, it is contrary to all experience to believe that +any man remembers all the things he has once known, and the +observed fallaciousness and evanescence of memory would thus tend +to substantiate rather than to controvert the idea that various +members of a tribe had been alive for an indefinite period. + +Without further elaborating the argument, it seems a justifiable +inference that the first conception primitive man would have of +his own life would not include the thought of natural death, but +would, conversely, connote the vague conception of endless life. +Our own ancestors, a few generations removed, had not got rid of +this conception, as the perpetual quest of the spring of eternal +youth amply testifies. A naturalist of our own day has suggested +that perhaps birds never die except by violence. The thought, +then, that man has a term of years beyond which "in the nature of +things," as the saying goes, he may not live, would have dawned +but gradually upon the developing intelligence of successive +generations of men; and we cannot feel sure that he would fully +have grasped the conception of a "natural" termination of human +life until he had shaken himself free from the idea that disease +is always the result of the magic practice of an enemy. Our +observation of historical man in antiquity makes it somewhat +doubtful whether this conception had been attained before the +close of the prehistoric period. If it had, this conception of +the mortality of man was one of the most striking scientific +inductions to which prehistoric man attained. Incidentally, it +may be noted that the conception of eternal life for the human +body being a more primitive idea than the conception of natural +death, the idea of the immortality of the spirit would be the +most natural of conceptions. The immortal spirit, indeed, would +be but a correlative of the immortal body, and the idea which we +shall see prevalent among the Egyptians that the soul persists +only as long as the body is intact--the idea upon which the +practice of mummifying the dead depended--finds a ready +explanation. But this phase of the subject carries us somewhat +afield. For our present purpose it suffices to have pointed out +that the conception of man's mortality--a conception which now +seems of all others the most natural and "innate"--was in all +probability a relatively late scientific induction of our +primitive ancestors. + +5. Turning from the consideration of the body to its mental +complement, we are forced to admit that here, also, our primitive +man must have made certain elementary observations that underlie +such sciences as psychology, mathematics, and political economy. +The elementary emotions associated with hunger and with satiety, +with love and with hatred, must have forced themselves upon the +earliest intelligence that reached the plane of conscious +self-observation. The capacity to count, at least to the number +four or five, is within the range of even animal intelligence. +Certain savages have gone scarcely farther than this; but our +primeval ancestor, who was forging on towards civilization, had +learned to count his fingers and toes, and to number objects +about him by fives and tens in consequence, before be passed +beyond the plane of numerous existing barbarians. How much beyond +this he had gone we need not attempt to inquire; but the +relatively high development of mathematics in the early +historical period suggests that primeval man had attained a not +inconsiderable knowledge of numbers. The humdrum vocation of +looking after a numerous progeny must have taught the mother the +rudiments of addition and subtraction; and the elements of +multiplication and division are implied in the capacity to carry +on even the rudest form of barter, such as the various tribes +must have practised from an early day. + +As to political ideas, even the crudest tribal life was based on +certain conceptions of ownership, at least of tribal ownership, +and the application of the principle of likeness and difference +to which we have already referred. Each tribe, of course, +differed in some regard from other tribes, and the recognition of +these differences implied in itself a political classification. A +certain tribe took possession of a particular hunting- ground, +which became, for the time being, its home, and over which it +came to exercise certain rights. An invasion of this territory by +another tribe might lead to war, and the banding together of the +members of the tribe to repel the invader implied both a +recognition of communal unity and a species of prejudice in favor +of that community that constituted a primitive patriotism. But +this unity of action in opposing another tribe would not prevent +a certain rivalry of interest between the members of the same +tribe, which would show itself more and more prominently as the +tribe increased in size. The association of two or more persons +implies, always, the ascendency of some and the subordination of +others. Leadership and subordination are necessary correlatives +of difference of physical and mental endowment, and rivalry +between leaders would inevitably lead to the formation of +primitive political parties. With the ultimate success and +ascendency of one leader, who secures either absolute power or +power modified in accordance with the advice of subordinate +leaders, we have the germs of an elaborate political system--an +embryo science of government. + +Meanwhile, the very existence of such a community implies the +recognition on the part of its members of certain individual +rights, the recognition of which is essential to communal +harmony. The right of individual ownership of the various +articles and implements of every-day life must be recognized, or +all harmony would be at an end. Certain rules of justice-- +primitive laws--must, by common consent, give protection to the +weakest members of the community. Here are the rudiments of a +system of ethics. It may seem anomalous to speak of this +primitive morality, this early recognition of the principles of +right and wrong, as having any relation to science. Yet, rightly +considered, there is no incongruity in such a citation. There +cannot well be a doubt that the adoption of those broad +principles of right and wrong which underlie the entire structure +of modern civilization was due to scientific induction,--in other +words, to the belief, based on observation and experience, that +the principles implied were essential to communal progress. He +who has scanned the pageant of history knows how often these +principles seem to be absent in the intercourse of men and +nations. Yet the ideal is always there as a standard by which all +deeds are judged. + + +It would appear, then, that the entire superstructure of later +science had its foundation in the knowledge and practice of +prehistoric man. The civilization of the historical period could +not have advanced as it has had there not been countless +generations of culture back of it. The new principles of science +could not have been evolved had there not been great basal +principles which ages of unconscious experiment had impressed +upon the mind of our race. Due meed of praise must be given, +then, to our primitive ancestor for his scientific +accomplishments; but justice demands that we should look a little +farther and consider the reverse side of the picture. We have had +to do, thus far, chiefly with the positive side of +accomplishment. We have pointed out what our primitive ancestor +knew, intimating, perhaps, the limitations of his knowledge; but +we have had little to say of one all-important feature of his +scientific theorizing. The feature in question is based on the +highly scientific desire and propensity to find explanations for +the phenomena of nature. Without such desire no progress could be +made. It is, as we have seen, the generalizing from experience +that constitutes real scientific progress; and yet, just as most +other good things can be overdone, this scientific propensity may +be carried to a disastrous excess. + +Primeval man did not escape this danger. He observed, he +reasoned, he found explanations; but he did not always +discriminate as to the logicality of his reasonings. He failed to +recognize the limitations of his knowledge. The observed +uniformity in the sequence of certain events impressed on his +mind the idea of cause and effect. Proximate causes known, he +sought remoter causes; childlike, his inquiring mind was always +asking, Why? and, childlike, he demanded an explicit answer. If +the forces of nature seemed to combat him, if wind and rain +opposed his progress and thunder and lightning seemed to menace +his existence, he was led irrevocably to think of those human +foes who warred with him, and to see, back of the warfare of the +elements, an inscrutable malevolent intelligence which took this +method to express its displeasure. But every other line of +scientific observation leads equally, following back a sequence +of events, to seemingly causeless beginnings. Modern science can +explain the lightning, as it can explain a great number of the +mysteries which the primeval intelligence could not penetrate. +But the primordial man could not wait for the revelations of +scientific investigation: he must vault at once to a final +solution of all scientific problems. He found his solution by +peopling the world with invisible forces, anthropomorphic in +their conception, like himself in their thought and action, +differing only in the limitations of their powers. His own dream +existence gave him seeming proof of the existence of an alter +ego, a spiritual portion of himself that could dissever itself +from his body and wander at will; his scientific inductions +seemed to tell him of a world of invisible beings, capable of +influencing him for good or ill. From the scientific exercise of +his faculties he evolved the all-encompassing generalizations of +invisible and all-powerful causes back of the phenomena of +nature. These generalizations, early developed and seemingly +supported by the observations of countless generations, came to +be among the most firmly established scientific inductions of our +primeval ancestor. They obtained a hold upon the mentality of our +race that led subsequent generations to think of them, sometimes +to speak of them, as "innate" ideas. The observations upon which +they were based are now, for the most part, susceptible of other +interpretations; but the old interpretations have precedent and +prejudice back of them, and they represent ideas that are more +difficult than almost any others to eradicate. Always, and +everywhere, superstitions based upon unwarranted early scientific +deductions have been the most implacable foes to the progress of +science. Men have built systems of philosophy around their +conception of anthropomorphic deities; they have linked to these +systems of philosophy the allied conception of the immutability +of man's spirit, and they have asked that scientific progress +should stop short at the brink of these systems of philosophy and +accept their dictates as final. Yet there is not to-day in +existence, and there never has been, one jot of scientific +evidence for the existence of these intangible anthropomorphic +powers back of nature that is not susceptible of scientific +challenge and of more logical interpretation. In despite of which +the superstitious beliefs are still as firmly fixed in the minds +of a large majority of our race as they were in the mind of our +prehistoric ancestor. The fact of this baleful heritage must not +be forgotten in estimating the debt of gratitude which historic +man owes to his barbaric predecessor. + + + +II. EGYPTIAN SCIENCE + +In the previous chapter we have purposely refrained from +referring to any particular tribe or race of historical man. Now, +however, we are at the beginnings of national existence, and we +have to consider the accomplishments of an individual race; or +rather, perhaps, of two or more races that occupied successively +the same geographical territory. But even now our studies must +for a time remain very general; we shall see little or nothing of +the deeds of individual scientists in the course of our study of +Egyptian culture. We are still, it must be understood, at the +beginnings of history; indeed, we must first bridge over the gap +from the prehistoric before we may find ourselves fairly on the +line of march of historical science. + +At the very outset we may well ask what constitutes the +distinction between prehistoric and historic epochs --a +distinction which has been constantly implied in much that we +have said. The reply savors somewhat of vagueness. It is a +distinction having to do, not so much with facts of human +progress as with our interpretation of these facts. When we speak +of the dawn of history we must not be understood to imply that, +at the period in question, there was any sudden change in the +intellectual status of the human race or in the status of any +individual tribe or nation of men. What we mean is that modern +knowledge has penetrated the mists of the past for the period we +term historical with something more of clearness and precision +than it has been able to bring to bear upon yet earlier periods. +New accessions of knowledge may thus shift from time to time the +bounds of the so-called historical period. The clearest +illustration of this is furnished by our interpretation of +Egyptian history. Until recently the biblical records of the +Hebrew captivity or service, together with the similar account of +Josephus, furnished about all that was known of Egyptian history +even of so comparatively recent a time as that of Ramses II. +(fifteenth century B.C.), and from that period on there was +almost a complete gap until the story was taken up by the Greek +historians Herodotus and Diodorus. It is true that the king-lists +of the Alexandrian historian, Manetho, were all along accessible +in somewhat garbled copies. But at best they seemed to supply +unintelligible lists of names and dates which no one was disposed +to take seriously. That they were, broadly speaking, true +historical records, and most important historical records at +that, was not recognized by modern scholars until fresh light had +been thrown on the subject from altogether new sources. + +These new sources of knowledge of ancient history demand a +moment's consideration. They are all-important because they have +been the means of extending the historical period of Egyptian +history (using the word history in the way just explained) by +three or four thousand years. As just suggested, that historical +period carried the scholarship of the early nineteenth century +scarcely beyond the fifteenth century B.C., but to-day's vision +extends with tolerable clearness to about the middle of the fifth +millennium B.C. This change has been brought about chiefly +through study of the Egyptian hieroglyphics. These hieroglyphics +constitute, as we now know, a highly developed system of writing; +a system that was practised for some thousands of years, but +which fell utterly into disuse in the later Roman period, and the +knowledge of which passed absolutely from the mind of man. For +about two thousand years no one was able to read, with any degree +of explicitness, a single character of this strange script, and +the idea became prevalent that it did not constitute a real +system of writing, but only a more or less barbaric system of +religious symbolism. The falsity of this view was shown early in +the nineteenth century when Dr. Thomas Young was led, through +study of the famous trilingual inscription of the Rosetta stone, +to make the first successful attempt at clearing up the mysteries +of the hieroglyphics. + +This is not the place to tell the story of his fascinating +discoveries and those of his successors. That story belongs to +nineteenth-century science, not to the science of the Egyptians. +Suffice it here that Young gained the first clew to a few of the +phonetic values of the Egyptian symbols, and that the work of +discovery was carried on and vastly extended by the Frenchman +Champollion, a little later, with the result that the firm +foundations of the modern science of Egyptology were laid. +Subsequently such students as Rosellini the Italian, Lepsius the +German, and Wilkinson the Englishman, entered the field, which in +due course was cultivated by De Rouge in France and Birch in +England, and by such distinguished latter-day workers as Chabas, +Mariette, Maspero, Amelineau, and De Morgan among the Frenchmen; +Professor Petrie and Dr. Budge in England; and Brugsch Pasha and +Professor Erman in Germany, not to mention a large coterie of +somewhat less familiar names. These men working, some of them in +the field of practical exploration, some as students of the +Egyptian language and writing, have restored to us a tolerably +precise knowledge of the history of Egypt from the time of the +first historical king, Mena, whose date is placed at about the +middle of the fifth century B.C. We know not merely the names of +most of the subsequent rulers, but some thing of the deeds of +many of them; and, what is vastly more important, we know, thanks +to the modern interpretation of the old literature, many things +concerning the life of the people, and in particular concerning +their highest culture, their methods of thought, and their +scientific attainments, which might well have been supposed to be +past finding out. Nor has modern investigation halted with the +time of the first kings; the recent explorations of such +archaeologists as Amelineau, De Morgan, and Petrie have brought +to light numerous remains of what is now spoken of as the +predynastic period--a period when the inhabitants of the Nile +Valley used implements of chipped stone, when their pottery was +made without the use of the potter's wheel, and when they buried +their dead in curiously cramped attitudes without attempt at +mummification. These aboriginal inhabitants of Egypt cannot +perhaps with strict propriety be spoken of as living within the +historical period, since we cannot date their relics with any +accuracy. But they give us glimpses of the early stages of +civilization upon which the Egyptians of the dynastic period were +to advance. + +It is held that the nascent civilization of these Egyptians of +the Neolithic, or late Stone Age, was overthrown by the invading +hosts of a more highly civilized race which probably came from +the East, and which may have been of a Semitic stock. The +presumption is that this invading people brought with it a +knowledge of the arts of war and peace, developed or adopted in +its old home. The introduction of these arts served to bridge +somewhat suddenly, so far as Egypt is concerned, that gap between +the prehistoric and the historic stage of culture to which we +have all along referred. The essential structure of that bridge, +let it now be clearly understood, consisted of a single element. +That element is the capacity to make written records: a knowledge +of the art of writing. Clearly understood, it is this element of +knowledge that forms the line bounding the historical period. +Numberless mementos are in existence that tell of the +intellectual activities of prehistoric man; such mementos as +flint implements, pieces of pottery, and fragments of bone, +inscribed with pictures that may fairly be spoken of as works of +art; but so long as no written word accompanies these records, so +long as no name of king or scribe comes down to us, we feel that +these records belong to the domain of archaeology rather than to +that of history. Yet it must be understood all along that these +two domains shade one into the other and, it has already been +urged, that the distinction between them is one that pertains +rather to modern scholarship than to the development of +civilization itself. Bearing this distinction still in mind, and +recalling that the historical period, which is to be the field of +our observation throughout the rest of our studies, extends for +Egypt well back into the fifth millennium B.C., let us briefly +review the practical phases of that civilization to which the +Egyptian had attained before the beginning of the dynastic +period. Since theoretical science is everywhere linked with the +mechanical arts, this survey will give us a clear comprehension +of the field that lies open for the progress of science in the +long stages of historical time upon which we are just entering. + +We may pass over such rudimentary advances in the direction of +civilization as are implied in the use of articulate language, +the application of fire to the uses of man, and the systematic +making of dwellings of one sort or another, since all of these +are stages of progress that were reached very early in the +prehistoric period. What more directly concerns us is to note +that a really high stage of mechanical development had been +reached before the dawnings of Egyptian history proper. All +manner of household utensils were employed; the potter's wheel +aided in the construction of a great variety of earthen vessels; +weaving had become a fine art, and weapons of bronze, including +axes, spears, knives, and arrow-heads, were in constant use. +Animals had long been domesticated, in particular the dog, the +cat, and the ox; the horse was introduced later from the East. +The practical arts of agriculture were practised almost as they +are at the present day in Egypt, there being, of course, the same +dependence then as now upon the inundations of the Nile. + +As to government, the Egyptian of the first dynasty regarded his +king as a demi-god to be actually deified after his death, and +this point of view was not changed throughout the stages of later +Egyptian history. In point of art, marvellous advances upon the +skill of the prehistoric man had been made, probably in part +under Asiatic influences, and that unique style of stilted yet +expressive drawing had come into vogue, which was to be +remembered in after times as typically Egyptian. More important +than all else, our Egyptian of the earliest historical period was +in possession of the art of writing. He had begun to make those +specific records which were impossible to the man of the Stone +Age, and thus he had entered fully upon the way of historical +progress which, as already pointed out, has its very foundation +in written records. From now on the deeds of individual kings +could find specific record. It began to be possible to fix the +chronology of remote events with some accuracy; and with this +same fixing of chronologies came the advent of true history. The +period which precedes what is usually spoken of as the first +dynasty in Egypt is one into which the present-day searcher is +still able to see but darkly. The evidence seems to suggest than +an invasion of relatively cultured people from the East +overthrew, and in time supplanted, the Neolithic civilization of +the Nile Valley. It is impossible to date this invasion +accurately, but it cannot well have been later than the year 5000 +B.C., and it may have been a great many centuries earlier than +this. Be the exact dates what they may, we find the Egyptian of +the fifth millennium B.C. in full possession of a highly +organized civilization. + +All subsequent ages have marvelled at the pyramids, some of which +date from about the year 4000 B.C., though we may note in passing +that these dates must not be taken too literally. The chronology +of ancient Egypt cannot as yet be fixed with exact accuracy, but +the disagreements between the various students of the subject +need give us little concern. For our present purpose it does not +in the least matter whether the pyramids were built three +thousand or four thousand years before the beginning of our era. +It suffices that they date back to a period long antecedent to +the beginnings of civilization in Western Europe. They prove that +the Egyptian of that early day had attained a knowledge of +practical mechanics which, even from the twentieth-century point +of view, is not to be spoken of lightly. It has sometimes been +suggested that these mighty pyramids, built as they are of great +blocks of stone, speak for an almost miraculous knowledge on the +part of their builders; but a saner view of the conditions gives +no warrant for this thought. Diodoras, the Sicilian, in his +famous World's History, written about the beginning of our era, +explains the building of the pyramids by suggesting that great +quantities of earth were piled against the side of the rising +structure to form an inclined plane up which the blocks of stone +were dragged. He gives us certain figures, based, doubtless, on +reports made to him by Egyptian priests, who in turn drew upon +the traditions of their country, perhaps even upon written +records no longer preserved. He says that one hundred and twenty +thousand men were employed in the construction of the largest +pyramid, and that, notwithstanding the size of this host of +workers, the task occupied twenty years. We must not place too +much dependence upon such figures as these, for the ancient +historians are notoriously given to exaggeration in recording +numbers; yet we need not doubt that the report given by Diodorus +is substantially accurate in its main outlines as to the method +through which the pyramids were constructed. A host of men +putting their added weight and strength to the task, with the aid +of ropes, pulleys, rollers, and levers, and utilizing the +principle of the inclined plane, could undoubtedly move and +elevate and place in position the largest blocks that enter into +the pyramids or--what seems even more wonderful--the most +gigantic obelisks, without the aid of any other kind of mechanism +or of any more occult power. The same hands could, as Diodorus +suggests, remove all trace of the debris of construction and +leave the pyramids and obelisks standing in weird isolation, as +if sprung into being through a miracle. + + +ASTRONOMICAL SCIENCE + +It has been necessary to bear in mind these phases of practical +civilization because much that we know of the purely scientific +attainments of the Egyptians is based upon modern observation of +their pyramids and temples. It was early observed, for example, +that the pyramids are obviously oriented as regards the direction +in which they face, in strict accordance with some astronomical +principle. Early in the nineteenth century the Frenchman Biot +made interesting studies in regard to this subject, and a hundred +years later, in our own time, Sir Joseph Norman Lockyer, +following up the work of various intermediary observers, has +given the subject much attention, making it the central theme of +his work on The Dawn of Astronomy.[1] Lockyer's researches make +it clear that in the main the temples of Egypt were oriented with +reference to the point at which the sun rises on the day of the +summer solstice. The time of the solstice had peculiar interest +for the Egyptians, because it corresponded rather closely with +the time of the rising of the Nile. The floods of that river +appear with very great regularity; the on-rushing tide reaches +the region of Heliopolis and Memphis almost precisely on the day +of the summer solstice. The time varies at different stages of +the river's course, but as the civilization of the early +dynasties centred at Memphis, observations made at this place had +widest vogue. + +Considering the all-essential character of the Nile +floods-without which civilization would be impossible in +Egypt--it is not strange that the time of their appearance should +be taken as marking the beginning of a new year. The fact that +their coming coincides with the solstice makes such a division of +the calendar perfectly natural. In point of fact, from the +earliest periods of which records have come down to us, the new +year of the Egyptians dates from the summer solstice. It is +certain that from the earliest historical periods the Egyptians +were aware of the approximate length of the year. It would be +strange were it otherwise, considering the ease with which a +record of days could be kept from Nile flood to Nile flood, or +from solstice to solstice. But this, of course, applies only to +an approximate count. There is some reason to believe that in the +earliest period the Egyptians made this count only 360 days. The +fact that their year was divided into twelve months of thirty +days each lends color to this belief; but, in any event, the +mistake was discovered in due time and a partial remedy was +applied through the interpolation of a "little month" of five +days between the end of the twelfth month and the new year. This +nearly but not quite remedied the matter. What it obviously +failed to do was to take account of that additional quarter of a +day which really rounds out the actual year. + +It would have been a vastly convenient thing for humanity had it +chanced that the earth had so accommodated its rotary motion with +its speed of transit about the sun as to make its annual flight +in precisely 360 days. Twelve lunar months of thirty days each +would then have coincided exactly with the solar year, and most +of the complexities of the calendar, which have so puzzled +historical students, would have been avoided; but, on the other +hand, perhaps this very simplicity would have proved detrimental +to astronomical science by preventing men from searching the +heavens as carefully as they have done. Be that as it may, the +complexity exists. The actual year of three hundred and +sixty-five and (about) one-quarter days cannot be divided evenly +into months, and some such expedient as the intercalation of days +here and there is essential, else the calendar will become +absolutely out of harmony with the seasons. + +In the case of the Egyptians, the attempt at adjustment was made, +as just noted, by the introduction of the five days, constituting +what the Egyptians themselves termed "the five days over and +above the year." These so-called epagomenal days were undoubtedly +introduced at a very early period. Maspero holds that they were +in use before the first Thinite dynasty, citing in evidence the +fact that the legend of Osiris explains these days as having been +created by the god Thot in order to permit Nuit to give birth to +all her children; this expedient being necessary to overcome a +ban which had been pronounced against Nuit, according to which +she could not give birth to children on any day of the year. But, +of course, the five additional days do not suffice fully to +rectify the calendar. There remains the additional quarter of a +day to be accounted for. This, of course, amounts to a full day +every fourth year. We shall see that later Alexandrian science +hit upon the expedient of adding a day to every fourth year; an +expedient which the Julian calendar adopted and which still gives +us our familiar leap-year. But, unfortunately, the ancient +Egyptian failed to recognize the need of this additional day, or +if he did recognize it he failed to act on his knowledge, and so +it happened that, starting somewhere back in the remote past with +a new year's day that coincided with the inundation of the Nile, +there was a constantly shifting maladjustment of calendar and +seasons as time went on. + +The Egyptian seasons, it should be explained, were three in +number: the season of the inundation, the season of the +seed-time, and the season of the harvest; each season being, of +course, four months in extent. Originally, as just mentioned, the +season of the inundations began and coincided with the actual +time of inundation. The more precise fixing of new year's day was +accomplished through observation of the time of the so-called +heliacal rising of the dog-star, Sirius, which bore the Egyptian +name Sothis. It chances that, as viewed from about the region of +Heliopolis, the sun at the time of the summer solstice occupies +an apparent position in the heavens close to the dog-star. Now, +as is well known, the Egyptians, seeing divinity back of almost +every phenomenon of nature, very naturally paid particular +reverence to so obviously influential a personage as the sun-god. +In particular they thought it fitting to do homage to him just as +he was starting out on his tour of Egypt in the morning; and that +they might know the precise moment of his coming, the Egyptian +astronomer priests, perched on the hill-tops near their temples, +were wont to scan the eastern horizon with reference to some star +which had been observed to precede the solar luminary. Of course +the precession of the equinoxes, due to that axial wobble in +which our clumsy earth indulges, would change the apparent +position of the fixed stars in reference to the sun, so that the +same star could not do service as heliacal messenger +indefinitely; but, on the other hand, these changes are so slow +that observations by many generations of astronomers would be +required to detect the shifting. It is believed by Lockyer, +though the evidence is not quite demonstrative, that the +astronomical observations of the Egyptians date back to a period +when Sothis, the dog-star, was not in close association with the +sun on the morning of the summer solstice. Yet, according to the +calculations of Biot, the heliacal rising of Sothis at the +solstice was noted as early as the year 3285 B.C., and it is +certain that this star continued throughout subsequent centuries +to keep this position of peculiar prestige. Hence it was that +Sothis came to be associated with Isis, one of the most important +divinities of Egypt, and that the day in which Sothis was first +visible in the morning sky marked the beginning of the new year; +that day coinciding, as already noted, with the summer solstice +and with the beginning of the Nile flow. + +But now for the difficulties introduced by that unreckoned +quarter of a day. Obviously with a calendar of 365 days only, at +the end of four years, the calendar year, or vague year, as the +Egyptians came to call it, had gained by one full day upon the +actual solar year-- that is to say, the heliacal rising of +Sothis, the dog- star, would not occur on new year's day of the +faulty calendar, but a day later. And with each succeeding period +of four years the day of heliacal rising, which marked the true +beginning of the year--and which still, of course, coincided with +the inundation--would have fallen another day behind the +calendar. In the course of 120 years an entire month would be +lost; and in 480 years so great would become the shifting that +the seasons would be altogether misplaced; the actual time of +inundations corresponding with what the calendar registered as +the seed-time, and the actual seed-time in turn corresponding +with the harvest-time of the calendar. + +At first thought this seems very awkward and confusing, but in +all probability the effects were by no means so much so in actual +practice. We need go no farther than to our own experience to +know that the names of seasons, as of months and days, come to +have in the minds of most of us a purely conventional +significance. Few of us stop to give a thought to the meaning of +the words January, February, etc., except as they connote certain +climatic conditions. If, then, our own calendar were so defective +that in the course of 120 years the month of February had shifted +back to occupy the position of the original January, the change +would have been so gradual, covering the period of two life-times +or of four or five average generations, that it might well escape +general observation. + +Each succeeding generation of Egyptians, then, may not improbably +have associated the names of the seasons with the contemporary +climatic conditions, troubling themselves little with the thought +that in an earlier age the climatic conditions for each period of +the calendar were quite different. We cannot well suppose, +however, that the astronomer priests were oblivious to the true +state of things. Upon them devolved the duty of predicting the +time of the Nile flood; a duty they were enabled to perform +without difficulty through observation of the rising of the +solstitial sun and its Sothic messenger. To these observers it +must finally have been apparent that the shifting of the seasons +was at the rate of one day in four years; this known, it required +no great mathematical skill to compute that this shifting would +finally effect a complete circuit of the calendar, so that after +(4 X 365 =) 1460 years the first day of the calendar year would +again coincide with the heliacal rising of Sothis and with the +coming of the Nile flood. In other words, 1461 vague years or +Egyptian calendar years Of 365 days each correspond to 1460 +actual solar years of 365 1/4 days each. This period, measured +thus by the heliacal rising of Sothis, is spoken of as the Sothic +cycle. + +To us who are trained from childhood to understand that the year +consists of (approximately) 365 1/4 days, and to know that the +calendar may be regulated approximately by the introduction of an +extra day every fourth year, this recognition of the Sothic cycle +seems simple enough. Yet if the average man of us will reflect +how little he knows, of his own knowledge, of the exact length of +the year, it will soon become evident that the appreciation of +the faults of the calendar and the knowledge of its periodical +adjustment constituted a relatively high development of +scientific knowledge on the part of the Egyptian astronomer. It +may be added that various efforts to reform the calendar were +made by the ancient Egyptians, but that they cannot be credited +with a satisfactory solution of the problem; for, of course, the +Alexandrian scientists of the Ptolemaic period (whose work we +shall have occasion to review presently) were not Egyptians in +any proper sense of the word, but Greeks. + +Since so much of the time of the astronomer priests was devoted +to observation of the heavenly bodies, it is not surprising that +they should have mapped out the apparent course of the moon and +the visible planets in their nightly tour of the heavens, and +that they should have divided the stars of the firmament into +more or less arbitrary groups or constellations. That they did so +is evidenced by various sculptured representations of +constellations corresponding to signs of the zodiac which still +ornament the ceilings of various ancient temples. Unfortunately +the decorative sense, which was always predominant with the +Egyptian sculptor, led him to take various liberties with the +distribution of figures in these representations of the +constellations, so that the inferences drawn from them as to the +exact map of the heavens as the Egyptians conceived it cannot be +fully relied upon. It appears, however, that the Egyptian +astronomer divided the zodiac into twenty-four decani, or +constellations. The arbitrary groupings of figures, with the aid +of which these are delineated, bear a close resemblance to the +equally arbitrary outlines which we are still accustomed to use +for the same purpose. + + +IDEAS OF COSMOLOGY + +In viewing this astronomical system of the Egyptians one cannot +avoid the question as to just what interpretation was placed upon +it as regards the actual mechanical structure of the universe. A +proximal answer to the question is supplied us with a good deal +of clearness. It appears that the Egyptian conceived the sky as a +sort of tangible or material roof placed above the world, and +supported at each of its four corners by a column or pillar, +which was later on conceived as a great mountain. The earth +itself was conceived to be a rectangular box, longer from north +to south than from east to west; the upper surface of this box, +upon which man lived, being slightly concave and having, of +course, the valley of the Nile as its centre. The pillars of +support were situated at the points of the compass; the northern +one being located beyond the Mediterranean Sea; the southern one +away beyond the habitable regions towards the source of the Nile, +and the eastern and western ones in equally inaccessible regions. +Circling about the southern side of the, world was a great river +suspended in mid-air on something comparable to mountain cliffs; +on which river the sun-god made his daily course in a boat, +fighting day by day his ever-recurring battle against Set, the +demon of darkness. The wide channel of this river enabled the +sun-god to alter his course from time to time, as he is observed +to do; in winter directing his bark towards the farther bank of +the channel; in summer gliding close to the nearer bank. As to +the stars, they were similar lights, suspended from the vault of +the heaven; but just how their observed motion of translation +across the heavens was explained is not apparent. It is more than +probable that no one explanation was, universally accepted. + +In explaining the origin of this mechanism of the heavens, the +Egyptian imagination ran riot. Each separate part of Egypt had +its own hierarchy of gods, and more or less its own explanations +of cosmogony. There does not appear to have been any one central +story of creation that found universal acceptance, any more than +there was one specific deity everywhere recognized as supreme +among the gods. Perhaps the most interesting of the cosmogonic +myths was that which conceived that Nuit, the goddess of night, +had been torn from the arms of her husband, Sibu the earth-god, +and elevated to the sky despite her protests and her husband's +struggles, there to remain supported by her four limbs, which +became metamorphosed into the pillars, or mountains, already +mentioned. The forcible elevation of Nuit had been effected on +the day of creation by a new god, Shu, who came forth from the +primeval waters. A painting on the mummy case of one Betuhamon, +now in the Turin Museum, illustrates, in the graphic manner so +characteristic of the Egyptians, this act of creation. As +Maspero[2] points out, the struggle of Sibu resulted in +contorted attitudes to which the irregularities of the earth's +surface are to be ascribed. + +In contemplating such a scheme of celestial mechanics as that +just outlined, one cannot avoid raising the question as to just +the degree of literalness which the Egyptians themselves put upon +it. We know how essentially eye-minded the Egyptian was, to use a +modern psychological phrase--that is to say, how essential to him +it seemed that all his conceptions should be visualized. The +evidences of this are everywhere: all his gods were made +tangible; he believed in the immortality of the soul, yet he +could not conceive of such immortality except in association with +an immortal body; he must mummify the body of the dead, else, as +he firmly believed, the dissolution of the spirit would take +place along with the dissolution of the body itself. His world +was peopled everywhere with spirits, but they were spirits +associated always with corporeal bodies; his gods found lodgment +in sun and moon and stars; in earth and water; in the bodies of +reptiles and birds and mammals. He worshipped all of these +things: the sun, the moon, water, earth, the spirit of the Nile, +the ibis, the cat, the ram, and apis the bull; but, so far as we +can judge, his imagination did not reach to the idea of an +absolutely incorporeal deity. Similarly his conception of the +mechanism of the heavens must be a tangibly mechanical one. He +must think of the starry firmament as a substantial entity which +could not defy the law of gravitation, and which, therefore, must +have the same manner of support as is required by the roof of a +house or temple. We know that this idea of the materiality of the +firmament found elaborate expression in those later cosmological +guesses which were to dominate the thought of Europe until the +time of Newton. We need not doubt, therefore, that for the +Egyptian this solid vault of the heavens had a very real +existence. If now and then some dreamer conceived the great +bodies of the firmament as floating in a less material +plenum--and such iconoclastic dreamers there are in all ages--no +record of his musings has come down to us, and we must freely +admit that if such thoughts existed they were alien to the +character of the Egyptian mind as a whole. + +While the Egyptians conceived the heavenly bodies as the +abiding-place of various of their deities, it does not appear +that they practised astrology in the later acceptance of that +word. This is the more remarkable since the conception of lucky +and unlucky days was carried by the Egyptians to the extremes of +absurdity. "One day was lucky or unlucky," says Erman,[3] +"according as a good or bad mythological incident took place on +that day. For instance, the 1st of Mechir, on which day the sky +was raised, and the 27th of Athyr, when Horus and, Set concluded +peace together and divided the world between them, were lucky +days; on the other hand, the 14th of Tybi, on which Isis and +Nephthys mourned for Osiris, was an unlucky day. With the unlucky +days, which, fortunately, were less in number than the lucky +days, they distinguished different degrees of ill-luck. Some were +very unlucky, others only threatened ill-luck, and many, like the +17th and the 27th Choiakh, were partly good and partly bad +according to the time of day. Lucky days might, as a rule, be +disregarded. At most it might be as well to visit some specially +renowned temple, or to 'celebrate a joyful day at home,' but no +particular precautions were really necessary; and, above all, it +was said, 'what thou also seest on the day is lucky.' It was +quite otherwise with the unlucky and dangerous days, which +imposed so many and such great limitations on people that those +who wished to be prudent were always obliged to bear them in mind +when determining on any course of action. Certain conditions were +easy to carry out. Music and singing were to be avoided on the +14th Tybi, the day of the mourning of Osiris, and no one was +allowed to wash on the 16th Tybi; whilst the name of Set might +not be pronounced on the 24th of Pharmuthi. Fish was forbidden on +certain days; and what was still more difficult in a country so +rich in mice, on the 12th of Tybi no mouse might be seen. The +most tiresome prohibitions, however, were those which occurred +not infrequently, namely, those concerning work and going out: +for instance, four times in Paophi the people had to 'do nothing +at all,' and five times to sit the whole day or half the day in +the house; and the same rule had to be observed each month. It +was impossible to rejoice if a child was born on the 23d of +Thoth; the parents knew it could not live. Those born on the 20th +of Choiakh would become blind, and those born on the 3d of +Choiakh, deaf." + + +CHARMS AND INCANTATIONS + +Where such conceptions as these pertained, it goes without saying +that charms and incantations intended to break the spell of the +unlucky omens were equally prevalent. Such incantations consisted +usually of the recitation of certain phrases based originally, it +would appear, upon incidents in the history of the gods. The +words which the god had spoken in connection with some lucky +incident would, it was thought, prove effective now in bringing +good luck to the human supplicant--that is to say, the magician +hoped through repeating the words of the god to exercise the +magic power of the god. It was even possible, with the aid of the +magical observances, partly to balk fate itself. Thus the person +predestined through birth on an unlucky day to die of a serpent +bite might postpone the time of this fateful visitation to +extreme old age. The like uncertainty attached to those spells +which one person was supposed to be able to exercise over +another. It was held, for example, that if something belonging to +an individual, such as a lock of hair or a paring of the nails, +could be secured and incorporated in a waxen figure, this figure +would be intimately associated with the personality of that +individual. An enemy might thus secure occult power over one; any +indignity practised upon the waxen figure would result in like +injury to its human prototype. If the figure were bruised or +beaten, some accident would overtake its double; if the image +were placed over a fire, the human being would fall into a fever, +and so on. But, of course, such mysterious evils as these would +be met and combated by equally mysterious processes; and so it +was that the entire art of medicine was closely linked with +magical practices. It was not, indeed, held, according to +Maspero, that the magical spells of enemies were the sole sources +of human ailments, but one could never be sure to what extent +such spells entered into the affliction; and so closely were the +human activities associated in the mind of the Egyptian with one +form or another of occult influences that purely physical +conditions were at a discount. In the later times, at any rate, +the physician was usually a priest, and there was a close +association between the material and spiritual phases of +therapeutics. Erman[4] tells us that the following formula had to +be recited at the preparation of all medicaments: "That Isis +might make free, make free. That Isis might make Horus free from +all evil that his brother Set had done to him when he slew his +father, Osiris. O Isis, great enchantress, free me, release me +from all evil red things, from the fever of the god, and the +fever of the goddess, from death and death from pain, and the +pain which comes over me; as thou hast freed, as thou hast +released thy son Horus, whilst I enter into the fire and come +forth from the water," etc. Again, when the invalid took the +medicine, an incantation had to be said which began thus: "Come +remedy, come drive it out of my heart, out of these limbs strong +in magic power with the remedy." He adds: "There may have been a +few rationalists amongst the Egyptian doctors, for the number of +magic formulae varies much in the different books. The book that +we have specially taken for a foundation for this account of +Egyptian medicine-- the great papyrus of the eighteenth dynasty +edited by Ebers[5]--contains, for instance, far fewer exorcisms +than some later writings with similar contents, probably because +the doctor who compiled this book of recipes from older sources +had very little liking for magic." + +It must be understood, however--indeed, what has just been said +implies as much--that the physician by no means relied upon +incantations alone; on the contrary, he equipped himself with an +astonishing variety of medicaments. He had a particular fondness +for what the modern physician speaks of as a "shot-gun" +prescription--one containing a great variety of ingredients. Not +only did herbs of many kinds enter into this, but such substances +as lizard's blood, the teeth of swine, putrid meat, the moisture +from pigs' ears, boiled horn, and numerous other even more +repellent ingredients. Whoever is familiar with the formulae +employed by European physicians even so recently as the +eighteenth century will note a striking similarity here. Erman +points out that the modern Egyptian even of this day holds +closely to many of the practices of his remote ancestor. In +particular, the efficacy of the beetle as a medicinal agent has +stood the test of ages of practice. "Against all kinds of +witchcraft," says an ancient formula, "a great scarabaeus beetle; +cut off his head and wings, boil him; put him in oil and lay him +out; then cook his head and wings, put them in snake fat, boil, +and let the patient drink the mixture." The modern Egyptian, says +Erman, uses almost precisely the same recipe, except that the +snake fat is replaced by modern oil. + +In evidence of the importance which was attached to practical +medicine in the Egypt of an early day, the names of several +physicians have come down to us from an age which has preserved +very few names indeed, save those of kings. In reference to this +Erman says[6]: "We still know the names of some of the early body +physicians of this time; Sechmetna'eonch, 'chief physician of the +Pharaoh,' and Nesmenan his chief, the 'superintendent of the +physicians of the Pharaoh.' The priests also of the +lioness-headed goddess Sechmet seem to have been famed for their +medical wisdom, whilst the son of this goddess, the demi-god +Imhotep, was in later times considered to be the creator of +medical knowledge. These ancient doctors of the New Empire do not +seem to have improved upon the older conceptions about the +construction of the human body." + +As to the actual scientific attainments of the Egyptian +physician, it is difficult to speak with precision. Despite the +cumbersome formulae and the grotesque incantations, we need not +doubt that a certain practical value attended his therapeutics. +He practised almost pure empiricism, however, and certainly it +must have been almost impossible to determine which ones, if any, +of the numerous ingredients of the prescription had real +efficacy. + +The practical anatomical knowledge of the physician, there is +every reason to believe, was extremely limited. At first thought +it might seem that the practice of embalming would have led to +the custom of dissecting human bodies, and that the Egyptians, as +a result of this, would have excelled in the knowledge of +anatomy. But the actual results were rather the reverse of this. +Embalming the dead, it must be recalled, was a purely religious +observance. It took place under the superintendence of the +priests, but so great was the reverence for the human body that +the priests themselves were not permitted to make the abdominal +incision which was a necessary preliminary of the process. This +incision, as we are informed by both Herodotus[7] and +Diodorus[8], was made by a special officer, whose status, if we +may believe the explicit statement of Diodorus, was quite +comparable to that of the modern hangman. The paraschistas, as he +was called, having performed his necessary but obnoxious +function, with the aid of a sharp Ethiopian stone, retired +hastily, leaving the remaining processes to the priests. These, +however, confined their observations to the abdominal viscera; +under no consideration did they make other incisions in the body. +It follows, therefore, that their opportunity for anatomical +observations was most limited. + +Since even the necessary mutilation inflicted on the corpse was +regarded with such horror, it follows that anything in the way of +dissection for a less sacred purpose was absolutely prohibited. +Probably the same prohibition extended to a large number of +animals, since most of these were held sacred in one part of +Egypt or another. Moreover, there is nothing in what we know of +the Egyptian mind to suggest the probability that any Egyptian +physician would make extensive anatomical observations for the +love of pure knowledge. All Egyptian science is eminently +practical. If we think of the Egyptian as mysterious, it is +because of the superstitious observances that we everywhere +associate with his daily acts; but these, as we have already +tried to make clear, were really based on scientific observations +of a kind, and the attempt at true inferences from these +observations. But whether or not the Egyptian physician desired +anatomical knowledge, the results of his inquiries were certainly +most meagre. The essentials of his system had to do with a series +of vessels, alleged to be twenty-two or twenty-four in number, +which penetrated the head and were distributed in pairs to the +various members of the body, and which were vaguely thought of as +carriers of water, air, excretory fluids, etc. Yet back of this +vagueness, as must not be overlooked, there was an all-essential +recognition of the heart as the central vascular organ. The heart +is called the beginning of all the members. Its vessels, we are +told, "lead to all the members; whether the doctor lays his +finger on the forehead, on the back of the head, on the hands, on +the place of the stomach (?), on the arms, or on the feet, +everywhere he meets with the heart, because its vessels lead to +all the members."[9] This recognition of the pulse must be +credited to the Egyptian physician as a piece of practical +knowledge, in some measure off-setting the vagueness of his +anatomical theories. + + +ABSTRACT SCIENCE + +But, indeed, practical knowledge was, as has been said over and +over, the essential characteristic of Egyptian science. Yet +another illustration of this is furnished us if we turn to the +more abstract departments of thought and inquire what were the +Egyptian attempts in such a field as mathematics. The answer does +not tend greatly to increase our admiration for the Egyptian +mind. We are led to see, indeed, that the Egyptian merchant was +able to perform all the computations necessary to his craft, but +we are forced to conclude that the knowledge of numbers scarcely +extended beyond this, and that even here the methods of reckoning +were tedious and cumbersome. Our knowledge of the subject rests +largely upon the so- called papyrus Rhind,[10] which is a sort of +mythological hand-book of the ancient Egyptians. Analyzing this +document, Professor Erman concludes that the knowledge of the +Egyptians was adequate to all practical requirements. Their +mathematics taught them "how in the exchange of bread for beer +the respective value was to be determined when converted into a +quantity of corn; how to reckon the size of a field; how to +determine how a given quantity of corn would go into a granary of +a certain size," and like every-day problems. Yet they were +obliged to make some of their simple computations in a very +roundabout way. It would appear, for example, that their mental +arithmetic did not enable them to multiply by a number larger +than two, and that they did not reach a clear conception of +complex fractional numbers. They did, indeed, recognize that each +part of an object divided into 10 pieces became 1/10 of that +object; they even grasped the idea of 2/3 this being a conception +easily visualized; but they apparently did not visualize such a +conception as 3/10 except in the crude form of 1/10 plus 1/10 +plus 1/10. Their entire idea of division seems defective. They +viewed the subject from the more elementary stand-point of +multiplication. Thus, in order to find out how many times 7 is +contained in 77, an existing example shows that the numbers +representing 1 times 7, 2 times 7, 4 times 7, 8 times 7 were set +down successively and various experimental additions made to find +out which sets of these numbers aggregated 77. + + --1 7 + --2 14 + --4 28 + --8 56 + +A line before the first, second, and fourth of these numbers +indicated that it is necessary to multiply 7 by 1 plus 2 plus +8--that is, by 11, in order to obtain 77; that is to say, 7 goes +11 times in 77. All this seems very cumbersome indeed, yet we +must not overlook the fact that the process which goes on in our +own minds in performing such a problem as this is precisely +similar, except that we have learned to slur over certain of the +intermediate steps with the aid of a memorized multiplication +table. In the last analysis, division is only the obverse side of +multiplication, and any one who has not learned his +multiplication table is reduced to some such expedient as that of +the Egyptian. Indeed, whenever we pass beyond the range of our +memorized multiplication table-which for most of us ends with the +twelves--the experimental character of the trial multiplication +through which division is finally effected does not so greatly +differ from the experimental efforts which the Egyptian was +obliged to apply to smaller numbers. + +Despite his defective comprehension of fractions, the Egyptian +was able to work out problems of relative complexity; for +example, he could determine the answer of such a problem as this: +a number together with its fifth part makes 21; what is the +number? The process by which the Egyptian solved this problem +seems very cumbersome to any one for whom a rudimentary knowledge +of algebra makes it simple, yet the method which we employ +differs only in that we are enabled, thanks to our hypothetical +x, to make a short cut, and the essential fact must not be +overlooked that the Egyptian reached a correct solution of the +problem. With all due desire to give credit, however, the fact +remains that the Egyptian was but a crude mathematician. Here, as +elsewhere, it is impossible to admire him for any high +development of theoretical science. First, last, and all the +time, he was practical, and there is nothing to show that the +thought of science for its own sake, for the mere love of +knowing, ever entered his head. + +In general, then, we must admit that the Egyptian had not +progressed far in the hard way of abstract thinking. He +worshipped everything about him because he feared the result of +failing to do so. He embalmed the dead lest the spirit of the +neglected one might come to torment him. Eye-minded as he was, he +came to have an artistic sense, to love decorative effects. But +he let these always take precedence over his sense of truth; as, +for example, when he modified his lists of kings at Abydos to fit +the space which the architect had left to be filled; he had no +historical sense to show to him that truth should take precedence +over mere decoration. And everywhere he lived in the same +happy-go-lucky way. He loved personal ease, the pleasures of the +table, the luxuries of life, games, recreations, festivals. He +took no heed for the morrow, except as the morrow might minister +to his personal needs. Essentially a sensual being, he scarcely +conceived the meaning of the intellectual life in the modern +sense of the term. He had perforce learned some things about +astronomy, because these were necessary to his worship of the +gods; about practical medicine, because this ministered to his +material needs; about practical arithmetic, because this aided +him in every-day affairs. The bare rudiments of an historical +science may be said to be crudely outlined in his defective lists +of kings. But beyond this he did not go. Science as science, and +for its own sake, was unknown to him. He had gods for all +material functions, and festivals in honor of every god; but +there was no goddess of mere wisdom in his pantheon. The +conception of Minerva was reserved for the creative genius of +another people. + + +III. SCIENCE OF BABYLONIA AND ASSYRIA + +Throughout classical antiquity Egyptian science was famous. We +know that Plato spent some years in Egypt in the hope of +penetrating the alleged mysteries of its fabled learning; and the +story of the Egyptian priest who patronizingly assured Solon that +the Greeks were but babes was quoted everywhere without +disapproval. Even so late as the time of Augustus, we find +Diodorus, the Sicilian, looking back with veneration upon the +Oriental learning, to which Pliny also refers with unbounded +respect. From what we have seen of Egyptian science, all this +furnishes us with a somewhat striking commentary upon the +attainments of the Greeks and Romans themselves. To refer at +length to this would be to anticipate our purpose; what now +concerns us is to recall that all along there was another nation, +or group of nations, that disputed the palm for scientific +attainments. This group of nations found a home in the valley of +the Tigris and Euphrates. Their land was named Mesopotamia by the +Greeks, because a large part of it lay between the two rivers +just mentioned. The peoples themselves are familiar to every one +as the Babylonians and the Assyrians. These peoples were of +Semitic stock--allied, therefore, to the ancient Hebrews and +Phoenicians and of the same racial stem with the Arameans and +Arabs. + +The great capital of the Babylonians during the later period of +their history was the famed city of Babylon itself; the most +famous capital of the Assyrians was Nineveh, that city to which, +as every Bible- student will recall, the prophet Jonah was +journeying when he had a much-exploited experience, the record of +which forms no part of scientific annals. It was the kings of +Assyria, issuing from their palaces in Nineveh, who dominated the +civilization of Western Asia during the heyday of Hebrew history, +and whose deeds are so frequently mentioned in the Hebrew +chronicles. Later on, in the year 606 B.C., Nineveh was +overthrown by the Medes[1] and Babylonians. The famous city was +completely destroyed, never to be rebuilt. Babylon, however, +though conquered subsequently by Cyrus and held in subjection by +Darius,[2] the Persian kings, continued to hold sway as a great +world-capital for some centuries. The last great historical event +that occurred within its walls was the death of Alexander the +Great, which took place there in the year 322 B.C. + +In the time of Herodotus the fame of Babylon was at its height, +and the father of history has left us a most entertaining account +of what he saw when he visited the wonderful capital. +Unfortunately, Herodotus was not a scholar in the proper +acceptance of the term. He probably had no inkling of the +Babylonian language, so the voluminous records of its literature +were entirely shut off from his observation. He therefore +enlightens us but little regarding the science of the +Babylonians, though his observations on their practical +civilization give us incidental references of no small +importance. Somewhat more detailed references to the scientific +attainments of the Babylonians are found in the fragments that +have come down to us of the writings of the great Babylonian +historian, Berosus,[3] who was born in Babylon about 330 B.C., +and who was, therefore, a contemporary of Alexander the Great. +But the writings of Berosus also, or at least such parts of them +as have come down to us, leave very much to be desired in point +of explicitness. They give some glimpses of Babylonian history, +and they detail at some length the strange mythical tales of +creation that entered into the Babylonian conception of +cosmogony--details which find their counterpart in the allied +recitals of the Hebrews. But taken all in all, the glimpses of +the actual state of Chaldean[4] learning, as it was commonly +called, amounted to scarcely more than vague wonder-tales. No one +really knew just what interpretation to put upon these tales +until the explorers of the nineteenth century had excavated the +ruins of the Babylonian and Assyrian cities, bringing to light +the relics of their wonderful civilization. But these relics +fortunately included vast numbers of written documents, inscribed +on tablets, prisms, and cylinders of terra-cotta. When +nineteenth-century scholarship had penetrated the mysteries of +the strange script, and ferreted out the secrets of an unknown +tongue, the world at last was in possession of authentic records +by which the traditions regarding the Babylonians and Assyrians +could be tested. Thanks to these materials, a new science +commonly spoken of as Assyriology came into being, and a most +important chapter of human history was brought to light. It +became apparent that the Greek ideas concerning Mesopotamia, +though vague in the extreme, were founded on fact. No one any +longer questions that the Mesopotamian civilization was fully on +a par with that of Egypt; indeed, it is rather held that +superiority lay with the Asiatics. Certainly, in point of purely +scientific attainments, the Babylonians passed somewhat beyond +their Egyptian competitors. All the evidence seems to suggest +also that the Babylonian civilization was even more ancient than +that of Egypt. The precise dates are here in dispute; nor for our +present purpose need they greatly concern us. But the +Assyrio-Babylonian records have much greater historical accuracy +as regards matters of chronology than have the Egyptian, and it +is believed that our knowledge of the early Babylonian history is +carried back, with some certainty, to King Sargon of Agade,[5] +for whom the date 3800 B.C. is generally accepted; while somewhat +vaguer records give us glimpses of periods as remote as the +sixth, perhaps even the seventh or eighth millenniums before our +era. + +At a very early period Babylon itself was not a capital and +Nineveh had not come into existence. The important cities, such +as Nippur and Shirpurla, were situated farther to the south. It +is on the site of these cities that the recent excavations have +been made, such as those of the University of Pennsylvania +expeditions at Nippur,[6] which are giving us glimpses into +remoter recesses of the historical period. + +Even if we disregard the more problematical early dates, we are +still concerned with the records of a civilization extending +unbroken throughout a period of about four thousand years; the +actual period is in all probability twice or thrice that. +Naturally enough, the current of history is not an unbroken +stream throughout this long epoch. It appears that at least two +utterly different ethnic elements are involved. A preponderance +of evidence seems to show that the earliest civilized inhabitants +of Mesopotamia were not Semitic, but an alien race, which is now +commonly spoken of as Sumerian. This people, of whom we catch +glimpses chiefly through the records of its successors, appears +to have been subjugated or overthrown by Semitic invaders, who, +coming perhaps from Arabia (their origin is in dispute), took +possession of the region of the Tigris and Euphrates, learned +from the Sumerians many of the useful arts, and, partly perhaps +because of their mixed lineage, were enabled to develop the most +wonderful civilization of antiquity. Could we analyze the details +of this civilization from its earliest to its latest period we +should of course find the same changes which always attend racial +progress and decay. We should then be able, no doubt, to speak of +certain golden epochs and their periods of decline. To a certain +meagre extent we are able to do this now. We know, for example, +that King Khammurabi, who lived about 2200 B.C., was a great +law-giver, the ancient prototype of Justinian; and the epochs of +such Assyrian kings as Sargon II., Asshurnazirpal, Sennacherib, +and Asshurbanapal stand out with much distinctness. Yet, as a +whole, the record does not enable us to trace with clearness the +progress of scientific thought. At best we can gain fewer +glimpses in this direction than in almost any other, for it is +the record of war and conquest rather than of the peaceful arts +that commanded the attention of the ancient scribe. So in dealing +with the scientific achievements of these peoples, we shall +perforce consider their varied civilizations as a unity, and +attempt, as best we may, to summarize their achievements as a +whole. For the most part, we shall not attempt to discriminate as +to what share in the final product was due to Sumerian, what to +Babylonian, and what to Assyrian. We shall speak of Babylonian +science as including all these elements; and drawing our +information chiefly from the relatively late Assyrian and +Babylonian sources, which, therefore, represent the culminating +achievements of all these ages of effort, we shall attempt to +discover what was the actual status of Mesopotamian science at +its climax. In so far as we succeed, we shall be able to judge +what scientific heritage Europe received from the Orient; for in +the records of Babylonian science we have to do with the Eastern +mind at its best. Let us turn to the specific inquiry as to the +achievements of the Chaldean scientist whose fame so dazzled the +eyes of his contemporaries of the classic world. + + +BABYLONIAN ASTRONOMY + +Our first concern naturally is astronomy, this being here, as in +Egypt, the first-born and the most important of the sciences. The +fame of the Chaldean astronomer was indeed what chiefly commanded +the admiration of the Greeks, and it was through the results of +astronomical observations that Babylonia transmitted her most +important influences to the Western world. "Our division of time +is of Babylonian origin," says Hornmel;[7] "to Babylonia we owe +the week of seven days, with the names of the planets for the +days of the week, and the division into hours and months." Hence +the almost personal interest which we of to-day must needs feel +in the efforts of the Babylonian star-gazer. + +It must not be supposed, however, that the Chaldean astronomer +had made any very extraordinary advances upon the knowledge of +the Egyptian "watchers of the night." After all, it required +patient observation rather than any peculiar genius in the +observer to note in the course of time such broad astronomical +conditions as the regularity of the moon's phases, and the +relation of the lunar periods to the longer periodical +oscillations of the sun. Nor could the curious wanderings of the +planets escape the attention of even a moderately keen observer. +The chief distinction between the Chaldean and Egyptian +astronomers appears to have consisted in the relative importance +they attached to various of the phenomena which they both +observed. The Egyptian, as we have seen, centred his attention +upon the sun. That luminary was the abode of one of his most +important gods. His worship was essentially solar. The +Babylonian, on the other hand, appears to have been peculiarly +impressed with the importance of the moon. He could not, of +course, overlook the attention-compelling fact of the solar year; +but his unit of time was the lunar period of thirty days, and his +year consisted of twelve lunar periods, or 360 days. He was +perfectly aware, however, that this period did not coincide with +the actual year; but the relative unimportance which he ascribed +to the solar year is evidenced by the fact that he interpolated +an added month to adjust the calendar only once in six years. +Indeed, it would appear that the Babylonians and Assyrians did +not adopt precisely the same method of adjusting the calendar, +since the Babylonians had two intercular months called Elul and +Adar, whereas the Assyrians had only a single such month, called +the second Adar.[8] (The Ve'Adar of the Hebrews.) This diversity +further emphasizes the fact that it was the lunar period which +received chief attention, the adjustment of this period with the +solar seasons being a necessary expedient of secondary +importance. It is held that these lunar periods have often been +made to do service for years in the Babylonian computations and +in the allied computations of the early Hebrews. The lives of the +Hebrew patriarchs, for example, as recorded in the Bible, are +perhaps reckoned in lunar "years." Divided by twelve, the "years" +of Methuselah accord fairly with the usual experience of mankind. + +Yet, on the other hand, the convenience of the solar year in +computing long periods of time was not unrecognized, since this +period is utilized in reckoning the reigns of the Assyrian kings. +It may be added that the reign of a king "was not reckoned from +the day of his accession, but from the Assyrian new year's day, +either before or after the day of accession. There does not +appear to have been any fixed rule as to which new year's day +should be chosen; but from the number of known cases, it appears +to have been the general practice to count the reigning years +from the new year's day nearest the accession, and to call the +period between the accession day and the first new year's day +'the beginning of the reign,' when the year from the new year's +day was called the first year, and the following ones were +brought successively from it. Notwithstanding, in the dates of +several Assyrian and Babylonian sovereigns there are cases of the +year of accession being considered as the first year, thus giving +two reckonings for the reigns of various monarchs, among others, +Shalmaneser, Sennacherib, Nebuchadrezzar."[9] This uncertainty as +to the years of reckoning again emphasizes the fact that the +solar year did not have for the Assyrian chronology quite the +same significance that it has for us. + +The Assyrian month commenced on the evening when the new moon was +first observed, or, in case the moon was not visible, the new +month started thirty days after the last month. Since the actual +lunar period is about twenty-nine and one-half days, a practical +adjustment was required between the months themselves, and this +was probably effected by counting alternate months as Only 29 +days in length. Mr. R. Campbell Thompson[10] is led by his +studies of the astrological tablets to emphasize this fact. He +believes that "the object of the astrological reports which +related to the appearance of the moon and sun was to help +determine and foretell the length of the lunar month." Mr. +Thompson believes also that there is evidence to show that the +interculary month was added at a period less than six years. In +point of fact, it does not appear to be quite clearly established +as to precisely how the adjustment of days with the lunar months, +and lunar months with the solar year, was effected. It is clear, +however, according to Smith, "that the first 28 days of every +month were divided into four weeks of seven days each; the +seventh, fourteenth, twenty-first, twenty-eighth days +respectively being Sabbaths, and that there was a general +prohibition of work on these days." Here, of course, is the +foundation of the Hebrew system of Sabbatical days which we have +inherited. The sacredness of the number seven itself--the belief +in which has not been quite shaken off even to this day --was +deduced by the Assyrian astronomer from his observation of the +seven planetary bodies--namely, Sin (the moon), Samas (the sun), +Umunpawddu (Jupiter), Dilbat (Venus), Kaimanu (Saturn), Gudud +(Mercury), Mustabarru-mutanu (Mars).[11] Twelve lunar periods, +making up approximately the solar year, gave peculiar importance +to the number twelve also. Thus the zodiac was divided into +twelve signs which astronomers of all subsequent times have +continued to recognize; and the duodecimal system of counting +took precedence with the Babylonian mathematicians over the more +primitive and, as it seems to us, more satisfactory decimal +system. + +Another discrepancy between the Babylonian and Egyptian years +appears in the fact that the Babylonian new year dates from about +the period of the vernal equinox and not from the solstice. +Lockyer associates this with the fact that the periodical +inundation of the Tigris and Euphrates occurs about the +equinoctial period, whereas, as we have seen, the Nile flood +comes at the time of the solstice. It is but natural that so +important a phenomenon as the Nile flood should make a strong +impression upon the minds of a people living in a valley. The +fact that occasional excessive inundations have led to most +disastrous results is evidenced in the incorporation of stories +of the almost total destruction of mankind by such floods among +the myth tales of all peoples who reside in valley countries. The +flooding of the Tigris and Euphrates had not, it is true, quite +the same significance for the Mesopotamians that the Nile flood +had for the Egyptians. Nevertheless it was a most important +phenomenon, and may very readily be imagined to have been the +most tangible index to the seasons. But in recognizing the time +of the inundations and the vernal equinox, the Assyrians did not +dethrone the moon from its accustomed precedence, for the year +was reckoned as commencing not precisely at the vernal equinox, +but at the new moon next before the equinox. + + +ASTROLOGY + +Beyond marking the seasons, the chief interests that actuated the +Babylonian astronomer in his observations were astrological. +After quoting Diodorus to the effect that the Babylonian priests +observed the position of certain stars in order to cast +horoscopes, Thompson tells us that from a very early day the very +name Chaldean became synonymous with magician. He adds that "from +Mesopotamia, by way of Greece and Rome, a certain amount of +Babylonian astrology made its way among the nations of the west, +and it is quite probable that many superstitions which we +commonly record as the peculiar product of western civilization +took their origin from those of the early dwellers on the +alluvial lands of Mesopotamia. One Assurbanipal, king of Assyria +B.C. 668-626, added to the royal library at Nineveh his +contribution of tablets, which included many series of documents +which related exclusively to the astrology of the ancient +Babylonians, who in turn had borrowed it with modifications from +the Sumerian invaders of the country. Among these must be +mentioned the series which was commonly called 'the Day of Bel,' +and which was decreed by the learned to have been written in the +time of the great Sargon I., king of Agade, 3800 B.C. With such +ancient works as these to guide them, the profession of deducing +omens from daily events reached such a pitch of importance in the +last Assyrian Empire that a system of making periodical reports +came into being. By these the king was informed of all the +occurrences in the heavens and on earth, and the results of +astrological studies in respect to after events. The heads of the +astrological profession were men of high rank and position, and +their office was hereditary. The variety of information contained +in these reports is best gathered from the fact that they were +sent from cities as far removed from each other as Assur in the +north and Erech in the south, and it can only be assumed that +they were despatched by runners, or men mounted on swift horses. +As reports also came from Dilbat, Kutba, Nippur, and Bursippa, +all cities of ancient foundation, the king was probably well +acquainted with the general course of events in his empire."[12] + +From certain passages in the astrological tablets, Thompson draws +the interesting conclusion that the Chaldean astronomers were +acquainted with some kind of a machine for reckoning time. He +finds in one of the tablets a phrase which he interprets to mean +measure-governor, and he infers from this the existence of a kind +of a calculator. He calls attention also to the fact that Sextus +Empiricus[13] states that the clepsydra was known to the +Chaldeans, and that Herodotus asserts that the Greeks borrowed +certain measures of time from the Babylonians. He finds further +corroboration in the fact that the Babylonians had a time-measure +by which they divided the day and the night; a measure called +kasbu, which contained two hours. In a report relating to the day +of the vernal equinox, it is stated that there are six kasbu of +the day and six kasbu of the night. + +While the astrologers deduced their omens from all the celestial +bodies known to them, they chiefly gave attention to the moon, +noting with great care the shape of its horns, and deducing such +a conclusion as that "if the horns are pointed the king will +overcome whatever he goreth," and that "when the moon is low at +its appearance, the submission (of the people) of a far country +will come."[14] The relations of the moon and sun were a source +of constant observation, it being noted whether the sun and moon +were seen together above the horizon; whether one set as the +other rose, and the like. And whatever the phenomena, there was +always, of course, a direct association between such phenomena +and the well-being of human kind--in particular the king, at +whose instance, and doubtless at whose expense, the observations +were carried out. + +From omens associated with the heavenly bodies it is but a step +to omens based upon other phenomena of nature, and we, shall see +in a moment that the Babylonian prophets made free use of their +opportunities in this direction also. But before we turn from the +field of astronomy, it will be well to inform ourselves as to +what system the Chaldean astronomer had invented in explanation +of the mechanics of the universe. Our answer to this inquiry is +not quite as definite as could be desired, the vagueness of the +records, no doubt, coinciding with the like vagueness in the +minds of the Chaldeans themselves. So far as we can interpret the +somewhat mystical references that have come down to us, however, +the Babylonian cosmology would seem to have represented the earth +as a circular plane surrounded by a great circular river, beyond +which rose an impregnable barrier of mountains, and resting upon +an infinite sea of waters. The material vault of the heavens was +supposed to find support upon the outlying circle of mountains. +But the precise mechanism through which the observed revolution +of the heavenly bodies was effected remains here, as with the +Egyptian cosmology, somewhat conjectural. The simple fact would +appear to be that, for the Chaldeans as for the Egyptians, +despite their most careful observations of the tangible phenomena +of the heavens, no really satisfactory mechanical conception of +the cosmos was attainable. We shall see in due course by what +faltering steps the European imagination advanced from the crude +ideas of Egypt and Babylonia to the relatively clear vision of +Newton and Laplace. + + +CHALDEAN MAGIC + +We turn now from the field of the astrologer to the closely +allied province of Chaldean magic--a province which includes the +other; which, indeed, is so all- encompassing as scarcely to +leave any phase of Babylonian thought outside its bounds. + +The tablets having to do with omens, exorcisms, and the like +magic practices make up an astonishingly large proportion of the +Babylonian records. In viewing them it is hard to avoid the +conclusion that the superstitions which they evidenced absolutely +dominated the life of the Babylonians of every degree. Yet it +must not be forgotten that the greatest inconsistencies +everywhere exist between the superstitious beliefs of a people +and the practical observances of that people. No other problem is +so difficult for the historian as that which confronts him when +he endeavors to penetrate the mysteries of an alien religion; and +when, as in the present case, the superstitions involved have +been transmitted from generation to generation, their exact +practical phases as interpreted by any particular generation must +be somewhat problematical. The tablets upon which our knowledge +of these omens is based are many of them from the libraries of +the later kings of Nineveh; but the omens themselves are, in such +cases, inscribed in the original Accadian form in which they have +come down from remote ages, accompanied by an Assyrian +translation. Thus the superstitions involved had back of them +hundreds of years, even thousands of years, of precedent; and we +need not doubt that the ideas with which they are associated were +interwoven with almost every thought and deed of the life of the +people. Professor Sayce assures us that the Assyrians and +Babylonians counted no fewer than three hundred spirits of +heaven, and six hundred spirits of earth. "Like the Jews of the +Talmud," he says, "they believed that the world was swarming with +noxious spirits, who produced the various diseases to which man +is liable, and might be swallowed with the food and drink which +support life." Fox Talbot was inclined to believe that exorcisms +were the exclusive means used to drive away the tormenting +spirits. This seems unlikely, considering the uniform association +of drugs with the magical practices among their people. Yet there +is certainly a strange silence of the tablets in regard to +medicine. Talbot tells us that sometimes divine images were +brought into the sick-chamber, and written texts taken from holy +books were placed on the walls and bound around the sick man's +members. If these failed, recourse was had to the influence of +the mamit, which the evil powers were unable to resist. On a +tablet, written in the Accadian language only, the Assyrian +version being taken, however, was found the following: + + 1. Take a white cloth. In it place the mamit, + 2. in the sick man's right hand. + 3. Take a black cloth, + 4. wrap it around his left hand. + 5. Then all the evil spirits (a long list of them is given) + 6. and the sins which he has committed + 7. shall quit their hold of him + 8. and shall never return. + + +The symbolism of the black cloth in the left hand seems evident. +The dying man repents of his former evil deeds, and he puts his +trust in holiness, symbolized by the white cloth in his right +hand. Then follow some obscure lines about the spirits: + + 1. Their heads shall remove from his head. + 2. Their heads shall let go his hands. + 3. Their feet shall depart from his feet. + +Which perhaps may be explained thus: we learn from another tablet +that the various classes of evil spirits troubled different parts +of the body; some injured the head, some the hands and the feet, +etc., therefore the passage before may mean "the spirits whose +power is over the hand shall loose their hands from his," etc. +"But," concludes Talbot, "I can offer no decided opinion upon +such obscure points of their superstition."[15] + +In regard to evil spirits, as elsewhere, the number seven had a +peculiar significance, it being held that that number of spirits +might enter into a man together. Talbot has translated[16] a +"wild chant" which he names "The Song of the Seven Spirits." + + 1. There are seven! There are seven! + 2. In the depths of the ocean there are seven! + 3. In the heights of the heaven there are seven! + 4. In the ocean stream in a palace they were born. + 5. Male they are not: female they are not! + 6. Wives they have not! Children are not born to them! + 7. Rules they have not! Government they know not! + 8. Prayers they hear not! + 9. There are seven! There are seven! Twice over there are +seven! + +The tablets make frequent allusion to these seven spirits. One +starts thus: + + 1. The god (---) shall stand by his bedside; + 2. These seven evil spirits he shall root out and shall expel +them from his body, + 3. and these seven shall never return to the sick man +again.[17] + + +Altogether similar are the exorcisms intended to ward off +disease. Professor Sayce has published translations of some of +these.[18] Each of these ends with the same phrase, and they +differ only in regard to the particular maladies from which +freedom is desired. One reads: + +"From wasting, from want of health, from the evil spirit of the +ulcer, from the spreading quinsy of the gullet, from the violent +ulcer, from the noxious ulcer, may the king of heaven preserve, +may the king of earth preserve." + +Another is phrased thus: + +"From the cruel spirit of the head, from the strong spirit of the +head, from the head spirit that departs not, from the head spirit +that comes not forth, from the head spirit that will not go, from +the noxious head spirit, may the king of heaven preserve, may the +king of earth preserve." + +As to omens having to do with the affairs of everyday life the +number is legion. For example, Moppert has published, in the +Journal Asiatique,[19] the translation of a tablet which contains +on its two sides several scores of birth-portents, a few of which +maybe quoted at random: + +"When a woman bears a child and it has the ears of a lion, a +strong king is in the country." "When a woman bears a child and +it has a bird's beak, that country is oppressed." "When a woman +bears a child and its right hand is wanting, that country goes to +destruction." "When a woman bears a child and its feet are +wanting, the roads of the country are cut; that house is +destroyed." "When a woman bears a child and at the time of its +birth its beard is grown, floods are in the country." "When a +woman bears a child and at the time of its birth its mouth is +open and speaks, there is pestilence in the country, the Air-god +inundates the crops of the country, injury in the country is +caused." + +Some of these portents, it will be observed, are not in much +danger of realization, and it is curious to surmise by what +stretch of the imagination they can have been invented. There is, +for example, on the same tablet just quoted, one reference which +assures us that "when a sheep bears a lion the forces march +multitudinously; the king has not a rival." There are other +omens, however, that are so easy of realization as to lead one to +suppose that any Babylonian who regarded all the superstitious +signs must have been in constant terror. Thus a tablet translated +by Professor Sayce[20] gives a long list of omens furnished by +dogs, in which we are assured that: + + 1. If a yellow dog enters into the palace, exit from that +palace will be baleful. + 2. If a dog to the palace goes, and on a throne lies down, that +palace is burned. + 3. if a black dog into a temple enters, the foundation of that +temple is not stable. + 4. If female dogs one litter bear, destruction to the city. + +It is needless to continue these citations, since they but +reiterate endlessly the same story. It is interesting to recall, +however, that the observations of animate nature, which were +doubtless superstitious in their motive, had given the +Babylonians some inklings of a knowledge of classification. Thus, +according to Menant,[21] some of the tablets from Nineveh, which +are written, as usual, in both the Sumerian and Assyrian +languages, and which, therefore, like practically all Assyrian +books, draw upon the knowledge of old Babylonia, give lists of +animals, making an attempt at classification. The dog, lion, and +wolf are placed in one category; the ox, sheep, and goat in +another; the dog family itself is divided into various races, as +the domestic dog, the coursing dog, the small dog, the dog of +Elan, etc. Similar attempts at classification of birds are found. +Thus, birds of rapid flight, sea-birds, and marsh-birds are +differentiated. Insects are classified according to habit; those +that attack plants, animals, clothing, or wood. Vegetables seem +to be classified according to their usefulness. One tablet +enumerates the uses of wood according to its adaptability for +timber-work of palaces, or construction of vessels, the making of +implements of husbandry, or even furniture. Minerals occupy a +long series in these tablets. They are classed according to their +qualities, gold and silver occupying a division apart; precious +stones forming another series. Our Babylonians, then, must be +credited with the development of a rudimentary science of natural +history. + + +BABYLONIAN MEDICINE + +We have just seen that medical practice in the Babylonian world +was strangely under the cloud of superstition. But it should be +understood that our estimate, through lack of correct data, +probably does much less than justice to the attainments of the +physician of the time. As already noted, the existing tablets +chance not to throw much light on the subject. It is known, +however, that the practitioner of medicine occupied a position of +some, authority and responsibility. The proof of this is found in +the clauses relating to the legal status of the physician which +are contained in the now famous code[22] of the Babylonian King +Khamurabi, who reigned about 2300 years before our era. These +clauses, though throwing no light on the scientific attainments +of the physician of the period, are too curious to be omitted. +They are clauses 215 to 227 of the celebrated code, and are as +follows: + +215. If a doctor has treated a man for a severe wound with a +lancet of bronze and has cured the man, or has opened a tumor +with a bronze lancet and has cured the man's eye, he shall +receive ten shekels of silver. + +216. If it was a freedman, he shall receive five shekels of +silver. + +217. If it was a man's slave, the owner of the slave shall give +the doctor two shekels of silver. + +218. If a physician has treated a free-born man for a severe +wound with a lancet of bronze and has caused the man to die, or +has opened a tumor of the man with a lancet of bronze and has +destroyed his eye, his hands one shall cut off. + +219. If the doctor has treated the slave of a freedman for a +severe wound with a bronze lancet and has caused him to die, he +shall give back slave for slave. + +220. If he has opened his tumor with a bronze lancet and has +ruined his eye, he shall pay the half of his price in money. + +221. If a doctor has cured the broken limb of a man, or has +healed his sick body, the patient shall pay the doctor five +shekels of silver. + +222. If it was a freedman, he shall give three shekels of silver. + +223. If it was a man's slave, the owner of the slave shall give +two shekels of silver to the doctor. + +224. If the doctor of oxen and asses has treated an ox or an ass +for a grave wound and has cured it, the owner of the ox or the +ass shall give to the doctor as his pay one-sixth of a shekel of +silver. + +225. If he has treated an ox or an ass for a severe wound and has +caused its death, he shall pay one-fourth of its price to the +owner of the ox or the ass. + +226. If a barber-surgeon, without consent of the owner of a +slave, has branded the slave with an indelible mark, one shall +cut off the hands of that barber. + +227. If any one deceive the surgeon-barber and make him brand a +slave with an indelible mark, one shall kill that man and bury +him in his house. The barber shall swear, "I did not mark him +wittingly," and he shall be guiltless. + + +ESTIMATES OF BABYLONIAN SCIENCE + +Before turning from the Oriental world it is perhaps worth while +to attempt to estimate somewhat specifically the world-influence +of the name, Babylonian science. Perhaps we cannot better gain an +idea as to the estimate put upon that science by the classical +world than through a somewhat extended quotation from a classical +author. Diodorus Siculus, who, as already noted, lived at about +the time of Augustus, and who, therefore, scanned in perspective +the entire sweep of classical Greek history, has left us a +striking summary which is doubly valuable because of its +comparisons of Babylonian with Greek influence. Having viewed the +science of Babylonia in the light of the interpretations made +possible by the recent study of original documents, we are +prepared to draw our own conclusions from the statements of the +Greek historian. Here is his estimate in the words of the quaint +translation made by Philemon Holland in the year 1700:[23] + + +"They being the most ancient Babylonians, hold the same station +and dignity in the Common-wealth as the Egyptian Priests do in +Egypt: For being deputed to Divine Offices, they spend all their +Time in the study of Philosophy, and are especially famous for +the Art of Astrology. They are mightily given to Divination, and +foretel future Events, and imploy themselves either by +Purifications, Sacrifices, or other Inchantments to avert Evils, +or procure good Fortune and Success. They are skilful likewise in +the Art of Divination, by the flying of Birds, and interpreting +of Dreams and Prodigies: And are reputed as true Oracles (in +declaring what will come to pass) by their exact and diligent +viewing the Intrals of the Sacrifices. But they attain not to +this Knowledge in the same manner as the Grecians do; for the +Chaldeans learn it by Tradition from their Ancestors, the Son +from the Father, who are all in the mean time free from all other +publick Offices and Attendances; and because their Parents are +their Tutors, they both learn every thing without Envy, and rely +with more confidence upon the truth of what is taught them; and +being train'd up in this Learning, from their very Childhood, +they become most famous Philosophers, (that Age being most +capable of Learning, wherein they spend much of their time). But +the Grecians for the most part come raw to this study, unfitted +and unprepar'd, and are long before they attain to the Knowledge +of this Philosophy: And after they have spent some small time in +this Study, they are many times call'd off and forc'd to leave +it, in order to get a Livelihood and Subsistence. And although +some, few do industriously apply themselves to Philosophy, yet +for the sake of Gain, these very Men are opinionative, and ever +and anon starting new and high Points, and never fix in the steps +of their Ancestors. But the Barbarians keeping constantly close +to the same thing, attain to a perfect and distinct Knowledge in +every particular. + +"But the Grecians, cunningly catching at all Opportunities of +Gain, make new Sects and Parties, and by their contrary Opinions +wrangling and quarelling concerning the chiefest Points, lead +their Scholars into a Maze; and being uncertain and doubtful what +to pitch upon for certain truth, their Minds are fluctuating and +in suspence all the days of their Lives, and unable to give a +certain assent unto any thing. For if any Man will but examine +the most eminent Sects of the Philosophers, he shall find them +much differing among themselves, and even opposing one another in +the most weighty parts of their Philosophy. But to return to the +Chaldeans, they hold that the World is eternal, which had neither +any certain Beginning, nor shall have any End; but all agree, +that all things are order'd, and this beautiful Fabrick is +supported by a Divine Providence, and that the Motions of the +Heavens are not perform'd by chance and of their own accord, but +by a certain and determinate Will and Appointment of the Gods. + +"Therefore from a long observation of the Stars, and an exact +Knowledge of the motions and influences of every one of them, +wherein they excel all others, they fortel many things that are +to come to pass. + +"They say that the Five Stars which some call Planets, but they +Interpreters, are most worthy of Consideration, both for their +motions and their remarkable influences, especially that which +the Grecians call Saturn. The brightest of them all, and which +often portends many and great Events, they call Sol, the other +Four they name Mars, Venus, Mercury, and Jupiter, with our own +Country Astrologers. They give the Name of Interpreters to these +Stars, because these only by a peculiar Motion do portend things +to come, and instead of Jupiters, do declare to Men before-hand +the good- will of the Gods; whereas the other Stars (not being of +the number of the Planets) have a constant ordinary motion. +Future Events (they say) are pointed at sometimes by their +Rising, and sometimes by their Setting, and at other times by +their Colour, as may be experienc'd by those that will diligently +observe it; sometimes foreshewing Hurricanes, at other times +Tempestuous Rains, and then again exceeding Droughts. By these, +they say, are often portended the appearance of Comets, Eclipses +of the Sun and Moon, Earthquakes and all other the various +Changes and remarkable effects in the Air, boding good and bad, +not only to Nations in general, but to Kings and Private Persons +in particular. Under the course of these Planets, they say are +Thirty Stars, which they call Counselling Gods, half of whom +observe what is done under the Earth, and the other half take +notice of the actions of Men upon the Earth, and what is +transacted in the Heavens. Once every Ten Days space (they say) +one of the highest Order of these Stars descends to them that are +of the lowest, like a Messenger sent from them above; and then +again another ascends from those below to them above, and that +this is their constant natural motion to continue for ever. The +chief of these Gods, they say, are Twelve in number, to each of +which they attribute a Month, and one Sign of the Twelve in the +Zodiack. + +"Through these Twelve Signs the Sun, Moon, and the other Five +Planets run their Course. The Sun in a Years time, and the Moon +in the space of a Month. To every one of the Planets they assign +their own proper Courses, which are perform'd variously in lesser +or shorter time according as their several motions are quicker or +slower. These Stars, they say, have a great influence both as to +good and bad in Mens Nativities; and from the consideration of +their several Natures, may be foreknown what will befal Men +afterwards. As they foretold things to come to other Kings +formerly, so they did to Alexander who conquer'd Darius, and to +his Successors Antigonus and Seleucus Nicator; and accordingly +things fell out as they declar'd; which we shall relate +particularly hereafter in a more convenient time. They tell +likewise private Men their Fortunes so certainly, that those who +have found the thing true by Experience, have esteem'd it a +Miracle, and above the reach of man to perform. Out of the Circle +of the Zodiack they describe Four and Twenty Stars, Twelve +towards the North Pole, and as many to the South. + +"Those which we see, they assign to the living; and the other +that do not appear, they conceive are Constellations for the +Dead; and they term them Judges of all things. The Moon, they +say, is in the lowest Orb; and being therefore next to the Earth +(because she is so small), she finishes her Course in a little +time, not through the swiftness of her Motion, but the shortness +of her Sphear. In that which they affirm (that she has but a +borrow'd light, and that when she is eclips'd, it's caus'd by the +interposition of the shadow of the Earth) they agree with the +Grecians. + +"Their Rules and Notions concerning the Eclipses of the Sun are +but weak and mean, which they dare not positively foretel, nor +fix a certain time for them. They have likewise Opinions +concerning the Earth peculiar to themselves, affirming it to +resemble a Boat, and to be hollow, to prove which, and other +things relating to the frame of the World, they abound in +Arguments; but to give a particular Account of 'em, we conceive +would be a thing foreign to our History. But this any Man may +justly and truly say, That the Chaldeans far exceed all other Men +in the Knowledge of Astrology, and have study'd it most of any +other Art or Science: But the number of years during which the +Chaldeans say, those of their Profession have given themselves to +the study of this natural Philosophy, is incredible; for when +Alexander was in Asia, they reckon'd up Four Hundred and Seventy +Thousand Years since they first began to observe the Motions of +the Stars." + + +Let us now supplement this estimate of Babylonian influence with +another estimate written in our own day, and quoted by one of the +most recent historians of Babylonia and Assyria.[24] The estimate +in question is that of Canon Rawlinson in his Great Oriental +Monarchies.[25] Of Babylonia he says: + +"Hers was apparently the genius which excogitated an alphabet; +worked out the simpler problems of arithmetic; invented +implements for measuring the lapse of time; conceived the idea of +raising enormous structures with the poorest of all materials, +clay; discovered the art of polishing, boring, and engraving +gems; reproduced with truthfulness the outlines of human and +animal forms; attained to high perfection in textile fabrics; +studied with success the motions of the heavenly bodies; +conceived of grammar as a science; elaborated a system of law; +saw the value of an exact chronology--in almost every branch of +science made a beginning, thus rendering it comparatively easy +for other nations to proceed with the superstructure.... It was +from the East, not from Egypt, that Greece derived her +architecture, her sculpture, her science, her philosophy, her +mathematical knowledge--in a word, her intellectual life. And +Babylon was the source to which the entire stream of Eastern +civilization may be traced. It is scarcely too much to say that, +but for Babylon, real civilization might not yet have dawned upon +the earth." + + +Considering that a period of almost two thousand years separates +the times of writing of these two estimates, the estimates +themselves are singularly in unison. They show that the greatest +of Oriental nations has not suffered in reputation at the hands +of posterity. It is indeed almost impossible to contemplate the +monuments of Babylonian and Assyrian civilization that are now +preserved in the European and American museums without becoming +enthusiastic. That certainly was a wonderful civilization which +has left us the tablets on which are inscribed the laws of a +Khamurabi on the one hand, and the art treasures of the palace of +an Asshurbanipal on the other. Yet a candid consideration of the +scientific attainments of the Babylonians and Assyrians can +scarcely arouse us to a like enthusiasm. In considering the +subject we have seen that, so far as pure science is concerned, +the efforts of the Babylonians and Assyrians chiefly centred +about the subjects of astrology and magic. With the records of +their ghost-haunted science fresh in mind, one might be forgiven +for a momentary desire to take issue with Canon Rawlinson's +words. We are assured that the scientific attainments of Europe +are almost solely to be credited to Babylonia and not to Egypt, +but we should not forget that Plato, the greatest of the Greek +thinkers, went to Egypt and not to Babylonia to pursue his +studies when he wished to penetrate the secrets of Oriental +science and philosophy. Clearly, then, classical Greece did not +consider Babylonia as having a monopoly of scientific knowledge, +and we of to-day, when we attempt to weigh the new evidence that +has come to us in recent generations with the Babylonian records +themselves, find that some, at least, of the heritages for which +Babylonia has been praised are of more than doubtful value. +Babylonia, for example, gave us our seven-day week and our system +of computing by twelves. But surely the world could have got on +as well without that magic number seven; and after some hundreds +of generations we are coming to feel that the decimal system of +the Egyptians has advantages over the duodecimal system of the +Babylonians. Again, the Babylonians did not invent the alphabet; +they did not even accept it when all the rest of the world had +recognized its value. In grammar and arithmetic, as with +astronomy, they seemed not to have advanced greatly, if at all, +upon the Egyptians. One field in which they stand out in +startling pre- eminence is the field of astrology; but this, in +the estimate of modern thought, is the very negation of science. +Babylonia impressed her superstitions on the Western world, and +when we consider the baleful influence of these superstitions, we +may almost question whether we might not reverse Canon +Rawlinson's estimate and say that perhaps but for Babylonia real +civilization, based on the application of true science, might +have dawned upon the earth a score of centuries before it did. +Yet, after all, perhaps this estimate is unjust. Society, like an +individual organism, must creep before it can walk, and perhaps +the Babylonian experiments in astrology and magic, which European +civilization was destined to copy for some three or four thousand +years, must have been made a part of the necessary evolution of +our race in one place or in another. That thought, however, need +not blind us to the essential fact, which the historian of +science must needs admit, that for the Babylonian, despite his +boasted culture, science spelled superstition. + + + +IV. THE DEVELOPMENT OF THE ALPHABET + +Before we turn specifically to the new world of the west, it +remains to take note of what may perhaps be regarded as the very +greatest achievement of ancient science. This was the analysis of +speech sounds, and the resulting development of a system of +alphabetical writing. To comprehend the series of scientific +inductions which led to this result, we must go back in +imagination and trace briefly the development of the methods of +recording thought by means of graphic symbols. In other words, we +must trace the evolution of the art of writing. In doing so we +cannot hold to national lines as we have done in the preceding +two chapters, though the efforts of the two great scientific +nations just considered will enter prominently into the story. + +The familiar Greek legend assures us that a Phoenician named +Kadmus was the first to bring a knowledge of letters into Europe. +An elaboration of the story, current throughout classical times, +offered the further explanation that the Phoenicians had in turn +acquired the art of writing from the Egyptians or Babylonians. +Knowledge as to the true origin and development of the art of +writing did not extend in antiquity beyond such vagaries as +these. Nineteenth-century studies gave the first real clews to an +understanding of the subject. These studies tended to +authenticate the essential fact on which the legend of Kadmus was +founded; to the extent, at least, of making it probable that the +later Grecian alphabet was introduced from Phoenicia--though not, +of course, by any individual named Kadmus, the latter being, +indeed, a name of purely Greek origin. Further studies of the +past generation tended to corroborate the ancient belief as to +the original source of the Phoenician alphabet, but divided +scholars between two opinions: the one contending that the +Egyptian hieroglyphics were the source upon which the Phoenicians +drew; and the other contending with equal fervor that the +Babylonian wedge character must be conceded that honor. + +But, as has often happened in other fields after years of +acrimonious controversy, a new discovery or two may suffice to +show that neither contestant was right. After the Egyptologists +of the school of De Rouge[1] thought they had demonstrated that +the familiar symbols of the Phoenician alphabet had been copied +from that modified form of Egyptian hieroglyphics known as the +hieratic writing, the Assyriologists came forward to prove that +certain characters of the Babylonian syllabary also show a +likeness to the alphabetical characters that seemingly could not +be due to chance. And then, when a settlement of the dispute +seemed almost hopeless, it was shown through the Egyptian +excavations that characters even more closely resembling those in +dispute had been in use all about the shores of the +Mediterranean, quite independently of either Egyptian or Assyrian +writings, from periods so ancient as to be virtually prehistoric. + +Coupled with this disconcerting discovery are the revelations +brought to light by the excavations at the sites of Knossos and +other long-buried cities of the island of Crete.[2] These +excavations, which are still in progress, show that the art of +writing was known and practised independently in Crete before +that cataclysmic overthrow of the early Greek civilization which +archaeologists are accustomed to ascribe to the hypothetical +invasion of the Dorians. The significance of this is that the art +of writing was known in Europe long before the advent of the +mythical Kadmus. But since the early Cretan scripts are not to be +identified with the scripts used in Greece in historical times, +whereas the latter are undoubtedly of lineal descent from the +Phoenician alphabet, the validity of the Kadmus legend, in a +modified form, must still be admitted. + +As has just been suggested, the new knowledge, particularly that +which related to the great antiquity of characters similar to the +Phoenician alphabetical signs, is somewhat disconcerting. Its +general trend, however, is quite in the same direction with most +of the new archaeological knowledge of recent decades---that is +to say, it tends to emphasize the idea that human civilization in +most of its important elaborations is vastly older than has +hitherto been supposed. It may be added, however, that no +definite clews are as yet available that enable us to fix even an +approximate date for the origin of the Phoenician alphabet. The +signs, to which reference has been made, may well have been in +existence for thousands of years, utilized merely as property +marks, symbols for counting and the like, before the idea of +setting them aside as phonetic symbols was ever conceived. +Nothing is more certain, in the judgment of the present-day +investigator, than that man learned to write by slow and painful +stages. It is probable that the conception of such an analysis of +speech sounds as would make the idea of an alphabet possible came +at a very late stage of social evolution, and as the culminating +achievement of a long series of improvements in the art of +writing. The precise steps that marked this path of intellectual +development can for the most part be known only by inference; yet +it is probable that the main chapters of the story may be +reproduced with essential accuracy. + + +FIRST STEPS + +For the very first chapters of the story we must go back in +imagination to the prehistoric period. Even barbaric man feels +the need of self-expression, and strives to make his ideas +manifest to other men by pictorial signs. The cave-dwellers +scratched pictures of men and animals on the surface of a +reindeer horn or mammoth tusk as mementos of his prowess. The +American Indian does essentially the same thing to-day, making +pictures that crudely record his successes in war and the chase. +The Northern Indian had got no farther than this when the white +man discovered America; but the Aztecs of the Southwest and the +Maya people of Yucatan had carried their picture- making to a +much higher state of elaboration.[3] They had developed systems +of pictographs or hieroglyphics that would doubtless in the +course of generations have been elaborated into alphabetical +systems, had not the Europeans cut off the civilization of which +they were the highest exponents. + +What the Aztec and Maya were striving towards in the sixteenth +century A.D., various Oriental nations had attained at least five +or six thousand years earlier. In Egypt at the time of the +pyramid-builders, and in Babylonia at the same epoch, the people +had developed systems of writing that enabled them not merely to +present a limited range of ideas pictorially, but to express in +full elaboration and with finer shades of meaning all the ideas +that pertain to highly cultured existence. The man of that time +made records of military achievements, recorded the transactions +of every-day business life, and gave expression to his moral and +spiritual aspirations in a way strangely comparable to the manner +of our own time. He had perfected highly elaborate systems of +writing. + + +EGYPTIAN WRITING + +Of the two ancient systems of writing just referred to as being +in vogue at the so-called dawnings of history, the more +picturesque and suggestive was the hieroglyphic system of the +Egyptians. This is a curiously conglomerate system of writing, +made up in part of symbols reminiscent of the crudest stages of +picture-writing, in part of symbols having the phonetic value of +syllables, and in part of true alphabetical letters. In a word, +the Egyptian writing represents in itself the elements of the +various stages through which the art of writing has developed.[4] +We must conceive that new features were from time to time added +to it, while the old features, curiously enough, were not given +up. + +Here, for example, in the midst of unintelligible lines and +pot-hooks, are various pictures that are instantly recognizable +as representations of hawks, lions, ibises, and the like. It can +hardly be questioned that when these pictures were first used +calligraphically they were meant to represent the idea of a bird +or animal. In other words, the first stage of picture-writing did +not go beyond the mere representation of an eagle by the picture +of an eagle. But this, obviously, would confine the presentation +of ideas within very narrow limits. In due course some inventive +genius conceived the thought of symbolizing a picture. To him the +outline of an eagle might represent not merely an actual bird, +but the thought of strength, of courage, or of swift progress. +Such a use of symbols obviously extends the range of utility of a +nascent art of writing. Then in due course some wonderful +psychologist--or perhaps the joint efforts of many generations of +psychologists--made the astounding discovery that the human +voice, which seems to flow on in an unbroken stream of endlessly +varied modulations and intonations, may really be analyzed into a +comparatively limited number of component sounds--into a few +hundreds of syllables. That wonderful idea conceived, it was only +a matter of time until it would occur to some other enterprising +genius that by selecting an arbitrary symbol to represent each +one of these elementary sounds it would be possible to make a +written record of the words of human speech which could be +reproduced--rephonated--by some one who had never heard the words +and did not know in advance what this written record contained. +This, of course, is what every child learns to do now in the +primer class, but we may feel assured that such an idea never +occurred to any human being until the peculiar forms of +pictographic writing just referred to had been practised for many +centuries. Yet, as we have said, some genius of prehistoric Egypt +conceived the idea and put it into practical execution, and the +hieroglyphic writing of which the Egyptians were in full +possession at the very beginning of what we term the historical +period made use of this phonetic system along with the +ideographic system already described. + +So fond were the Egyptians of their pictorial symbols used +ideographically that they clung to them persistently throughout +the entire period of Egyptian history. They used symbols as +phonetic equivalents very frequently, but they never learned to +depend upon them exclusively. The scribe always interspersed his +phonetic signs with some other signs intended as graphic aids. +After spelling a word out in full, he added a picture, sometimes +even two or three pictures, representative of the individual +thing, or at least of the type of thing to which the word +belongs. Two or three illustrations will make this clear. + +Thus qeften, monkey, is spelled out in full, but the picture of a +monkey is added as a determinative; second, qenu, cavalry, after +being spelled, is made unequivocal by the introduction of a +picture of a horse; third, temati, wings, though spelled +elaborately, has pictures of wings added; and fourth, tatu, +quadrupeds, after being spelled, has a picture of a quadruped, +and then the picture of a hide, which is the usual determinative +of a quadruped, followed by three dashes to indicate the plural +number. + +It must not be supposed, however, that it was a mere whim which +led the Egyptians to the use of this system of determinatives. +There was sound reason back of it. It amounted to no more than +the expedient we adopt when we spell "to," "two," or "too," in +indication of a single sound with three different meanings. The +Egyptian language abounds in words having more than one meaning, +and in writing these it is obvious that some means of distinction +is desirable. The same thing occurs even more frequently in the +Chinese language, which is monosyllabic. The Chinese adopt a more +clumsy expedient, supplying a different symbol for each of the +meanings of a syllable; so that while the actual word-sounds of +their speech are only a few hundreds in number, the characters of +their written language mount high into the thousands. + + +BABYLONIAN WRITING + +While the civilization of the Nile Valley was developing this +extraordinary system of hieroglyphics, the inhabitants of +Babylonia were practising the art of writing along somewhat +different lines. It is certain that they began with +picture-making, and that in due course they advanced to the +development of the syllabary; but, unlike their Egyptian cousins, +the men of Babylonia saw fit to discard the old system when they +had perfected a better one.[5] So at a very early day their +writing--as revealed to us now through the recent +excavations--had ceased to have that pictorial aspect which +distinguishes the Egyptian script. What had originally been +pictures of objects--fish, houses, and the like--had come to be +represented by mere aggregations of wedge-shaped marks. As the +writing of the Babvlonians was chiefly inscribed on soft clay, +the adaptation of this wedge-shaped mark in lieu of an ordinary +line was probably a mere matter of convenience, since the +sharp-cornered implement used in making the inscription naturally +made a wedge-shaped impression in the clay. That, however, is a +detail. The essential thing is that the Babylonian had so fully +analyzed the speech-sounds that he felt entire confidence in +them, and having selected a sufficient number of conventional +characters--each made up of wedge-shaped lines--to represent all +the phonetic sounds of his language, spelled the words out in +syllables and to some extent dispensed with the determinative +signs which, as we have seen, played so prominent a part in the +Egyptian writing. His cousins the Assyrians used habitually a +system of writing the foundation of which was an elaborate +phonetic syllabary; a system, therefore, far removed from the old +crude pictograph, and in some respects much more developed than +the complicated Egyptian method; yet, after all, a system that +stopped short of perfection by the wide gap that separates the +syllabary from the true alphabet. + +A brief analysis of speech sounds will aid us in understanding +the real nature of the syllabary. Let us take for consideration +the consonantal sound represented by the letter b. A moment's +consideration will make it clear that this sound enters into a +large number of syllables. There are, for example, at least +twenty vowel sounds in the English language, not to speak of +certain digraphs; that is to say, each of the important vowels +has from two to six sounds. Each of these vowel sounds may enter +into combination with the b sound alone to form three syllables; +as ba, ab, bal, be, eb, bel, etc. Thus there are at least sixty +b-sound syllables. But this is not the end, for other consonantal +sounds may be associated in the syllables in such combinations as +bad, bed, bar, bark, cab, etc. As each of the other twenty odd +consonantal sounds may enter into similar combinations, it is +obvious that there are several hundreds of fundamental syllables +to be taken into account in any syllabic system of writing. For +each of these syllables a symbol must be set aside and held in +reserve as the representative of that particular sound. A perfect +syllabary, then, would require some hundred or more of symbols to +represent b sounds alone; and since the sounds for c, d, f, and +the rest are equally varied, the entire syllabary would run into +thousands of characters, almost rivalling in complexity the +Chinese system. But in practice the most perfect syllabary, Such +as that of the Babylonians, fell short of this degree of +precision through ignoring the minor shades of sound; just as our +own alphabet is content to represent some thirty vowel sounds by +five letters, ignoring the fact that a, for example, has really +half a dozen distinct phonetic values. By such slurring of sounds +the syllabary is reduced far below its ideal limits; yet even so +it retains three or four hundred characters. + +In point of fact, such a work as Professor Delitzsch's Assyrian +Grammar[6] presents signs for three hundred and thirty-four +syllables, together with sundry alternative signs and +determinatives to tax the memory of the would-be reader of +Assyrian. Let us take for example a few of the b sounds. It has +been explained that the basis of the Assyrian written character +is a simple wedge-shaped or arrow-head mark. Variously repeated +and grouped, these marks make up the syllabic characters. + +To learn some four hundred such signs as these was the task set, +as an equivalent of learning the a b c's, to any primer class in +old Assyria in the long generations when that land was the +culture Centre of the world. Nor was the task confined to the +natives of Babylonia and Assyria alone. About the fifteenth +century B.C., and probably for a long time before and after that +period, the exceedingly complex syllabary of the Babylonians was +the official means of communication throughout western Asia and +between Asia and Egypt, as we know from the chance discovery of a +collection of letters belonging to the Egyptian king Khun-aten, +preserved at Tel-el-Amarna. In the time of Ramses the Great the +Babylonian writing was in all probability considered by a +majority of the most highly civilized people in the world to be +the most perfect script practicable. Doubtless the average scribe +of the time did not in the least realize the waste of energy +involved in his labors, or ever suspect that there could be any +better way of writing. + +Yet the analysis of any one of these hundreds of syllables into +its component phonetic elements--had any one been genius enough +to make such analysis-- ould have given the key to simpler and +better things. But such an analysis was very hard to make, as the +sequel shows. Nor is the utility of such an analysis +self-evident, as the experience of the Egyptians proved. The +vowel sound is so intimately linked with the consonant--the +con-sonant, implying this intimate relation in its very +name--that it seemed extremely difficult to give it individual +recognition. To set off the mere labial beginning of the sound by +itself, and to recognize it as an all-essential element of +phonation, was the feat at which human intelligence so long +balked. The germ of great things lay in that analysis. It was a +process of simplification, and all art development is from the +complex to the simple. Unfortunately, however, it did not seem a +simplification, but rather quite the reverse. We may well suppose +that the idea of wresting from the syllabary its secret of +consonants and vowels, and giving to each consonantal sound a +distinct sign, seemed a most cumbersome and embarrassing +complication to the ancient scholars--that is to say, after the +time arrived when any one gave such an idea expression. We can +imagine them saying: "You will oblige us to use four signs +instead of one to write such an elementary syllable as 'bard,' +for example. Out upon such endless perplexity!" Nor is such a +suggestion purely gratuitous, for it is an historical fact that +the old syllabary continued to be used in Babylon hundreds of +years after the alphabetical system had been introduced.[7] +Custom is everything in establishing our prejudices. The Japanese +to-day rebel against the introduction of an alphabet, thinking it +ambiguous. + +Yet, in the end, conservatism always yields, and so it was with +opposition to the alphabet. Once the idea of the consonant had +been firmly grasped, the old syllabary was doomed, though +generations of time might be required to complete the +obsequies--generations of time and the influence of a new nation. +We have now to inquire how and by whom this advance was made. + + +THE ALPHABET ACHIEVED + +We cannot believe that any nation could have vaulted to the final +stage of the simple alphabetical writing without tracing the +devious and difficult way of the pictograph and the syllabary. It +is possible, however, for a cultivated nation to build upon the +shoulders of its neighbors, and, profiting by the experience of +others, to make sudden leaps upward and onward. And this is +seemingly what happened in the final development of the art of +writing. For while the Babylonians and Assyrians rested content +with their elaborate syllabary, a nation on either side of them, +geographically speaking, solved the problem, which they perhaps +did not even recognize as a problem; wrested from their syllabary +its secret of consonants and vowels, and by adopting an arbitrary +sign for each consonantal sound, produced that most wonderful of +human inventions, the alphabet. + +The two nations credited with this wonderful achievement are the +Phoenicians and the Persians. But it is not usually conceded that +the two are entitled to anything like equal credit. The Persians, +probably in the time of Cyrus the Great, used certain characters +of the Babylonian script for the construction of an alphabet; but +at this time the Phoenician alphabet had undoubtedly been in use +for some centuries, and it is more than probable that the Persian +borrowed his idea of an alphabet from a Phoenician source. And +that, of course, makes all the difference. Granted the idea of an +alphabet, it requires no great reach of constructive genius to +supply a set of alphabetical characters; though even here, it may +be added parenthetically, a study of the development of alphabets +will show that mankind has all along had a characteristic +propensity to copy rather than to invent. + +Regarding the Persian alphabet-maker, then, as a copyist rather +than a true inventor, it remains to turn attention to the +Phoenician source whence, as is commonly believed, the original +alphabet which became "the mother of all existing alphabets" came +into being. It must be admitted at the outset that evidence for +the Phoenician origin of this alphabet is traditional rather than +demonstrative. The Phoenicians were the great traders of +antiquity; undoubtedly they were largely responsible for the +transmission of the alphabet from one part of the world to +another, once it had been invented. Too much credit cannot be +given them for this; and as the world always honors him who makes +an idea fertile rather than the originator of the idea, there can +be little injustice in continuing to speak of the Phoenicians as +the inventors of the alphabet. But the actual facts of the case +will probably never be known. For aught we know, it may have been +some dreamy-eyed Israelite, some Babylonian philosopher, some +Egyptian mystic, perhaps even some obscure Cretan, who gave to +the hard-headed Phoenician trader this conception of a +dismembered syllable with its all-essential, elemental, +wonder-working consonant. But it is futile now to attempt even to +surmise on such unfathomable details as these. Suffice it that +the analysis was made; that one sign and no more was adopted for +each consonantal sound of the Semitic tongue, and that the entire +cumbersome mechanism of the Egyptian and Babylonian writing +systems was rendered obsolescent. These systems did not yield at +once, to be sure; all human experience would have been set at +naught had they done so. They held their own, and much more than +held their own, for many centuries. After the Phoenicians as a +nation had ceased to have importance; after their original script +had been endlessly modified by many alien nations; after the +original alphabet had made the conquest of all civilized Europe +and of far outlying portions of the Orient--the Egyptian and +Babylonian scribes continued to indite their missives in the same +old pictographs and syllables. + +The inventive thinker must have been struck with amazement when, +after making the fullest analysis of speech-sounds of which he +was capable, he found himself supplied with only a score or so of +symbols. Yet as regards the consonantal sounds he had exhausted +the resources of the Semitic tongue. As to vowels, he scarcely +considered them at all. It seemed to him sufficient to use one +symbol for each consonantal sound. This reduced the hitherto +complex mechanism of writing to so simple a system that the +inventor must have regarded it with sheer delight. On the other +hand, the conservative scholar doubtless thought it distinctly +ambiguous. In truth, it must be admitted that the system was +imperfect. It was a vast improvement on the old syllabary, but it +had its drawbacks. Perhaps it had been made a bit too simple; +certainly it should have had symbols for the vowel sounds as well +as for the consonants. Nevertheless, the vowel-lacking alphabet +seems to have taken the popular fancy, and to this day Semitic +people have never supplied its deficiencies save with certain +dots and points. + +Peoples using the Aryan speech soon saw the defect, and the +Greeks supplied symbols for several new sounds at a very early +day.[8] But there the matter rested, and the alphabet has +remained imperfect. For the purposes of the English language +there should certainly have been added a dozen or more new +characters. It is clear, for example, that, in the interest of +explicitness, we should have a separate symbol for the vowel +sound in each of the following syllables: bar, bay, bann, ball, +to cite a single illustration. + +There is, to be sure, a seemingly valid reason for not extending +our alphabet, in the fact that in multiplying syllables it would +be difficult to select characters at once easy to make and +unambiguous. Moreover, the conservatives might point out, with +telling effect, that the present alphabet has proved admirably +effective for about three thousand years. Yet the fact that our +dictionaries supply diacritical marks for some thirty vowels +sounds to indicate the pronunciation of the words of our +every-day speech, shows how we let memory and guessing do the +work that might reasonably be demanded of a really complete +alphabet. But, whatever its defects, the existing alphabet is a +marvellous piece of mechanism, the result of thousands of years +of intellectual effort. It is, perhaps without exception, the +most stupendous invention of the human intellect within +historical times--an achievement taking rank with such great +prehistoric discoveries as the use of articulate speech, the +making of a fire, and the invention of stone implements, of the +wheel and axle, and of picture-writing. It made possible for the +first time that education of the masses upon which all later +progress of civilization was so largely to depend. + + + +V. THE BEGINNINGS OF GREEK SCIENCE + +Herodotus, the Father of History, tells us that once upon a +time--which time, as the modern computator shows us, was about +the year 590 B.C. --a war had risen between the Lydians and the +Medes and continued five years. "In these years the Medes often +discomfited the Lydians and the Lydians often discomfited the +Medes (and among other things they fought a battle by night); and +yet they still carried on the war with equally balanced +fortitude. In the sixth year a battle took place in which it +happened, when the fight had begun, that suddenly the day became +night. And this change of the day Thales, the Milesian, had +foretold to the Ionians, laying down as a limit this very year in +which the change took place. The Lydians, however, and the Medes, +when they saw that it had become night instead of day, ceased +from their fighting and were much more eager, both of them, that +peace should be made between them." + +This memorable incident occurred while Alyattus, father of +Croesus, was king of the Lydians. The modern astronomer, +reckoning backward, estimates this eclipse as occurring probably +May 25th, 585 B.C. The date is important as fixing a mile-stone +in the chronology of ancient history, but it is doubly memorable +because it is the first recorded instance of a predicted eclipse. +Herodotus, who tells the story, was not born until about one +hundred years after the incident occurred, but time had not +dimmed the fame of the man who had performed the necromantic feat +of prophecy. Thales, the Milesian, thanks in part at least to +this accomplishment, had been known in life as first on the list +of the Seven Wise Men of Greece, and had passed into history as +the father of Greek philosophy. We may add that he had even found +wider popular fame through being named by Hippolytus, and then by +Father aesop, as the philosopher who, intent on studying the +heavens, fell into a well; "whereupon," says Hippolytus, "a +maid-servant named Thratta laughed at him and said, 'In his +search for things in the sky he does not see what is at his +feet.' " + +Such citations as these serve to bring vividly to mind the fact +that we are entering a new epoch of thought. Hitherto our studies +have been impersonal. Among Egyptians and Babylonians alike we +have had to deal with classes of scientific records, but we have +scarcely come across a single name. Now, however, we shall begin +to find records of the work of individual investigators. In +general, from now on, we shall be able to trace each great idea, +if not to its originator, at least to some one man of genius who +was prominent in bringing it before the world. The first of these +vitalizers of thought, who stands out at the beginnings of Greek +history, is this same Thales, of Miletus. His is not a very +sharply defined personality as we look back upon it, and we can +by no means be certain that all the discoveries which are +ascribed to him are specifically his. Of his individuality as a +man we know very little. It is not even quite certain as to where +he was born; Miletus is usually accepted as his birthplace, but +one tradition makes him by birth a Phenician. It is not at all in +question, however, that by blood he was at least in part an +Ionian Greek. It will be recalled that in the seventh century +B.C., when Thales was born--and for a long time thereafter--the +eastern shores of the aegean Sea were quite as prominently the +centre of Greek influence as was the peninsula of Greece itself. +Not merely Thales, but his followers and disciples, Anaximander +and Anaximenes, were born there. So also was Herodotas, the +Father of History, not to extend the list. There is nothing +anomalous, then, in the fact that Thales, the father of Greek +thought, was born and passed his life on soil that was not +geographically a part of Greece; but the fact has an important +significance of another kind. Thanks to his environment, Thales +was necessarily brought more or less in contact with Oriental +ideas. There was close commercial contact between the land of his +nativity and the great Babylonian capital off to the east, as +also with Egypt. Doubtless this association was of influence in +shaping the development of Thales's mind. Indeed, it was an +accepted tradition throughout classical times that the Milesian +philosopher had travelled in Egypt, and had there gained at least +the rudiments of his knowledge of geometry. In the fullest sense, +then, Thales may be regarded as representing a link in the chain +of thought connecting the learning of the old Orient with the +nascent scholarship of the new Occident. Occupying this position, +it is fitting that the personality of Thales should partake +somewhat of mystery; that the scene may not be shifted too +suddenly from the vague, impersonal East to the individualism of +Europe. + +All of this, however, must not be taken as casting any doubt upon +the existence of Thales as a real person. Even the dates of his +life--640 to 546 B.C.--may be accepted as at least approximately +trustworthy; and the specific discoveries ascribed to him +illustrate equally well the stage of development of Greek +thought, whether Thales himself or one of his immediate disciples +were the discoverer. We have already mentioned the feat which was +said to have given Thales his great reputation. That Thales was +universally credited with having predicted the famous eclipse is +beyond question. That he actually did predict it in any precise +sense of the word is open to doubt. At all events, his prediction +was not based upon any such precise knowledge as that of the +modern astronomer. There is, indeed, only one way in which he +could have foretold the eclipse, and that is through knowledge of +the regular succession of preceding eclipses. But that knowledge +implies access on the part of some one to long series of records +of practical observations of the heavens. Such records, as we +have seen, existed in Egypt and even more notably in Babylonia. +That these records were the source of the information which +established the reputation of Thales is an unavoidable inference. +In other words, the magical prevision of the father of Greek +thought was but a reflex of Oriental wisdom. Nevertheless, it +sufficed to establish Thales as the father of Greek astronomy. In +point of fact, his actual astronomical attainments would appear +to have been meagre enough. There is nothing to show that he +gained an inkling of the true character of the solar system. He +did not even recognize the sphericity of the earth, but held, +still following the Oriental authorities, that the world is a +flat disk. Even his famous cosmogonic guess, according to which +water is the essence of all things and the primordial element out +of which the earth was developed, is but an elaboration of the +Babylonian conception. + +When we turn to the other field of thought with which the name of +Thales is associated--namely, geometry--we again find evidence of +the Oriental influence. The science of geometry, Herodotus +assures us, was invented in Egypt. It was there an eminently +practical science, being applied, as the name literally suggests, +to the measurement of the earth's surface. Herodotus tells us +that the Egyptians were obliged to cultivate the science because +the periodical inundations washed away the boundary-lines between +their farms. The primitive geometer, then, was a surveyor. The +Egyptian records, as now revealed to us, show that the science +had not been carried far in the land of its birth. The Egyptian +geometer was able to measure irregular pieces of land only +approximately. He never fully grasped the idea of the +perpendicular as the true index of measurement for the triangle, +but based his calculations upon measurements of the actual side +of that figure. Nevertheless, he had learned to square the circle +with a close approximation to the truth, and, in general, his +measurement sufficed for all his practical needs. Just how much +of the geometrical knowledge which added to the fame of Thales +was borrowed directly from the Egyptians, and how much he +actually created we cannot be sure. Nor is the question raised in +disparagement of his genius. Receptivity is the first +prerequisite to progressive thinking, and that Thales reached out +after and imbibed portions of Oriental wisdom argues in itself +for the creative character of his genius. Whether borrower of +originator, however, Thales is credited with the expression of +the following geometrical truths: + +1. That the circle is bisected by its diameter. + +2. That the angles at the base of an isosceles triangle are +equal. + +3. That when two straight lines cut each other the vertical +opposite angles are equal. + +4. That the angle in a semicircle is a right angle. + +5. That one side and one acute angle of a right-angle triangle +determine the other sides of the triangle. + +It was by the application of the last of these principles that +Thales is said to have performed the really notable feat of +measuring the distance of a ship from the shore, his method being +precisely the same in principle as that by which the guns are +sighted on a modern man-of-war. Another practical demonstration +which Thales was credited with making, and to which also his +geometrical studies led him, was the measurement of any tall +object, such as a pyramid or building or tree, by means of its +shadow. The method, though simple enough, was ingenious. It +consisted merely in observing the moment of the day when a +perpendicular stick casts a shadow equal to its own length. +Obviously the tree or monument would also cast a shadow equal to +its own height at the same moment. It remains then but to measure +the length of this shadow to determine the height of the object. +Such feats as this evidence the practicality of the genius of +Thales. They suggest that Greek science, guided by imagination, +was starting on the high-road of observation. We are told that +Thales conceived for the first time the geometry of lines, and +that this, indeed, constituted his real advance upon the +Egyptians. We are told also that he conceived the eclipse of the +sun as a purely natural phenomenon, and that herein lay his +advance upon the Chaldean point of view. But if this be true +Thales was greatly in advance of his time, for it will be +recalled that fully two hundred years later the Greeks under +Nicias before Syracuse were so disconcerted by the appearance of +an eclipse, which was interpreted as a direct omen and warning, +that Nicias threw away the last opportunity to rescue his army. +Thucydides, it is true, in recording this fact speaks +disparagingly of the superstitious bent of the mind of Nicias, +but Thucydides also was a man far in advance of his time. + +All that we know of the psychology of Thales is summed up in the +famous maxim, "Know thyself," a maxim which, taken in connection +with the proven receptivity of the philosopher's mind, suggests +to us a marvellously rounded personality. + +The disciples or successors of Thales, Anaximander and +Anaximenes, were credited with advancing knowledge through the +invention or introduction of the sundial. We may be sure, +however, that the gnomon, which is the rudimentary sundial, had +been known and used from remote periods in the Orient, and the +most that is probable is that Anaximander may have elaborated +some special design, possibly the bowl- shaped sundial, through +which the shadow of the gnomon would indicate the time. The same +philosopher is said to have made the first sketch of a +geographical map, but this again is a statement which modern +researches have shown to be fallacious, since a Babylonian +attempt at depicting the geography of the world is still +preserved to us on a clay tablet. Anaximander may, however, have +been the first Greek to make an attempt of this kind. Here again +the influence of Babylonian science upon the germinating Western +thought is suggested. + +It is said that Anaximander departed from Thales's conception of +the earth, and, it may be added, from the Babylonian conception +also, in that he conceived it as a cylinder, or rather as a +truncated cone, the upper end of which is the habitable portion. +This conception is perhaps the first of these guesses through +which the Greek mind attempted to explain the apparent fixity of +the earth. To ask what supports the earth in space is most +natural, but the answer given by Anaximander, like that more +familiar Greek solution which transformed the cone, or cylinder, +into the giant Atlas, is but another illustration of that +substitution of unwarranted inference for scientific induction +which we have already so often pointed out as characteristic of +the primitive stages of thought. + +Anaximander held at least one theory which, as vouched for by +various copyists and commentators, entitles him to be considered +perhaps the first teacher of the idea of organic evolution. +According to this idea, man developed from a fishlike ancestor, +"growing up as sharks do until able to help himself and then +coming forth on dry land."[1] The thought here expressed finds +its germ, perhaps, in the Babylonian conception that everything +came forth from a chaos of waters. Yet the fact that the thought +of Anaximander has come down to posterity through such various +channels suggests that the Greek thinker had got far enough away +from the Oriental conception to make his view seem to his +contemporaries a novel and individual one. Indeed, nothing we +know of the Oriental line of thought conveys any suggestion of +the idea of transformation of species, whereas that idea is +distinctly formulated in the traditional views of Anaximander. + + + +VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +Diogenes Laertius tells a story about a youth who, clad in a +purple toga, entered the arena at the Olympian games and asked to +compete with the other youths in boxing. He was derisively denied +admission, presumably because he was beyond the legitimate age +for juvenile contestants. Nothing daunted, the youth entered the +lists of men, and turned the laugh on his critics by coming off +victor. The youth who performed this feat was named Pythagoras. +He was the same man, if we may credit the story, who afterwards +migrated to Italy and became the founder of the famous Crotonian +School of Philosophy; the man who developed the religion of the +Orphic mysteries; who conceived the idea of the music of the +spheres; who promulgated the doctrine of metempsychosis; who +first, perhaps, of all men clearly conceived the notion that this +world on which we live is a ball which moves in space and which +may be habitable on every side. + +A strange development that for a stripling pugilist. But we must +not forget that in the Greek world athletics held a peculiar +place. The chief winner of Olympian games gave his name to an +epoch (the ensuing Olympiad of four years), and was honored +almost before all others in the land. A sound mind in a sound +body was the motto of the day. To excel in feats of strength and +dexterity was an accomplishment that even a philosopher need not +scorn. It will be recalled that aeschylus distinguished himself +at the battle of Marathon; that Thucydides, the greatest of Greek +historians, was a general in the Peloponnesian War; that +Xenophon, the pupil and biographer of Socrates, was chiefly famed +for having led the Ten Thousand in the memorable campaign of +Cyrus the Younger; that Plato himself was credited with having +shown great aptitude in early life as a wrestler. If, then, +Pythagoras the philosopher was really the Pythagoras who won the +boxing contest, we may suppose that in looking back upon this +athletic feat from the heights of his priesthood--for he came to +be almost deified--he regarded it not as an indiscretion of his +youth, but as one of the greatest achievements of his life. Not +unlikely he recalled with pride that he was credited with being +no less an innovator in athletics than in philosophy. At all +events, tradition credits him with the invention of "scientific" +boxing. Was it he, perhaps, who taught the Greeks to strike a +rising and swinging blow from the hip, as depicted in the famous +metopes of the Parthenon? If so, the innovation of Pythagoras was +as little heeded in this regard in a subsequent age as was his +theory of the motion of the earth; for to strike a swinging blow +from the hip, rather than from the shoulder, is a trick which the +pugilist learned anew in our own day. + +But enough of pugilism and of what, at best, is a doubtful +tradition. Our concern is with another "science" than that of the +arena. We must follow the purple-robed victor to Italy--if, +indeed, we be not over-credulous in accepting the tradition--and +learn of triumphs of a different kind that have placed the name +of Pythagoras high on the list of the fathers of Grecian thought. +To Italy? Yes, to the western limits of the Greek world. Here it +was, beyond the confines of actual Greek territory, that Hellenic +thought found its second home, its first home being, as we have +seen, in Asia Minor. Pythagoras, indeed, to whom we have just +been introduced, was born on the island of Samos, which lies near +the coast of Asia Minor, but he probably migrated at an early day +to Crotona, in Italy. There he lived, taught, and developed his +philosophy until rather late in life, when, having incurred the +displeasure of his fellow-citizens, he suffered the not unusual +penalty of banishment. + +Of the three other great Italic leaders of thought of the early +period, Xenophanes came rather late in life to Elea and founded +the famous Eleatic School, of which Parmenides became the most +distinguished ornament. These two were Ionians, and they lived in +the sixth century before our era. Empedocles, the Sicilian, was +of Doric origin. He lived about the middle of the fifth century +B.C., at a time, therefore, when Athens had attained a position +of chief glory among the Greek states; but there is no evidence +that Empedocles ever visited that city, though it was rumored +that he returned to the Peloponnesus to die. The other great +Italic philosophers just named, living, as we have seen, in the +previous century, can scarcely have thought of Athens as a centre +of Greek thought. Indeed, the very fact that these men lived in +Italy made that peninsula, rather than the mother-land of Greece, +the centre of Hellenic influence. But all these men, it must +constantly be borne in mind, were Greeks by birth and language, +fully recognized as such in their own time and by posterity. Yet +the fact that they lived in a land which was at no time a part of +the geographical territory of Greece must not be forgotten. They, +or their ancestors of recent generations, had been pioneers among +those venturesome colonists who reached out into distant portions +of the world, and made homes for themselves in much the same +spirit in which colonists from Europe began to populate America +some two thousand years later. In general, colonists from the +different parts of Greece localized themselves somewhat +definitely in their new homes; yet there must naturally have been +a good deal of commingling among the various families of +pioneers, and, to a certain extent, a mingling also with the +earlier inhabitants of the country. This racial mingling, +combined with the well-known vitalizing influence of the pioneer +life, led, we may suppose, to a more rapid and more varied +development than occurred among the home-staying Greeks. In proof +of this, witness the remarkable schools of philosophy which, as +we have seen, were thus developed at the confines of the Greek +world, and which were presently to invade and, as it were, take +by storm the mother-country itself. + +As to the personality of these pioneer philosophers of the West, +our knowledge is for the most part more or less traditional. What +has been said of Thales may be repeated, in the main, regarding +Pythagoras, Parmenides, and Empedocles. That they were real +persons is not at all in question, but much that is merely +traditional has come to be associated with their names. +Pythagoras was the senior, and doubtless his ideas may have +influenced the others more or less, though each is usually spoken +of as the founder of an independent school. Much confusion has +all along existed, however, as to the precise ideas which were to +be ascribed to each of the leaders. Numberless commentators, +indeed, have endeavored to pick out from among the traditions of +antiquity, aided by such fragments, of the writing of the +philosophers as have come down to us, the particular ideas that +characterized each thinker, and to weave these ideas into +systems. But such efforts, notwithstanding the mental energy that +has been expended upon them, were, of necessity, futile, since, +in the first place, the ancient philosophers themselves did not +specialize and systematize their ideas according to modern +notions, and, in the second place, the records of their +individual teachings have been too scantily preserved to serve +for the purpose of classification. It is freely admitted that +fable has woven an impenetrable mesh of contradictions about the +personalities of these ancient thinkers, and it would be folly to +hope that this same artificer had been less busy with their +beliefs and theories. When one reads that Pythagoras advocated an +exclusively vegetable diet, yet that he was the first to train +athletes on meat diet; that he sacrificed only inanimate things, +yet that he offered up a hundred oxen in honor of his great +discovery regarding the sides of a triangle, and such like +inconsistencies in the same biography, one gains a realizing +sense of the extent to which diverse traditions enter into the +story as it has come down to us. And yet we must reflect that +most men change their opinions in the course of a long lifetime, +and that the antagonistic reports may both be true. + +True or false, these fables have an abiding interest, since they +prove the unique and extraordinary character of the personality +about which they are woven. The alleged witticisms of a Whistler, +in our own day, were doubtless, for the most part, quite unknown +to Whistler himself, yet they never would have been ascribed to +him were they not akin to witticisms that he did originate--were +they not, in short, typical expressions of his personality. And +so of the heroes of the past. "It is no ordinary man," said +George Henry Lewes, speaking of Pythagoras, "whom fable exalts +into the poetic region. Whenever you find romantic or miraculous +deeds attributed, be certain that the hero was great enough to +maintain the weight of the crown of this fabulous glory."[1] We +may not doubt, then, that Pythagoras, Parmenides, and Empedocles, +with whose names fable was so busy throughout antiquity, were men +of extraordinary personality. We are here chiefly concerned, +however, neither with the personality of the man nor yet with the +precise doctrines which each one of them taught. A knowledge of +the latter would be interesting were it attainable, but in the +confused state of the reports that have come down to us we cannot +hope to be able to ascribe each idea with precision to its proper +source. At best we can merely outline, even here not too +precisely, the scientific doctrines which the Italic philosophers +as a whole seem to have advocated. + +First and foremost, there is the doctrine that the earth is a +sphere. Pythagoras is said to have been the first advocate of +this theory; but, unfortunately, it is reported also that +Parmenides was its author. This rivalship for the discovery of an +important truth we shall see repeated over and over in more +recent times. Could we know the whole truth, it would perhaps +appear that the idea of the sphericity of the earth was +originated long before the time of the Greek philosophers. But it +must be admitted that there is no record of any sort to give +tangible support to such an assumption. So far as we can +ascertain, no Egyptian or Babylonian astronomer ever grasped the +wonderful conception that the earth is round. That the Italic +Greeks should have conceived that idea was perhaps not so much +because they were astronomers as because they were practical +geographers and geometers. Pythagoras, as we have noted, was born +at Samos, and, therefore, made a relatively long sea voyage in +passing to Italy. Now, as every one knows, the most simple and +tangible demonstration of the convexity of the earth's surface is +furnished by observation of an approaching ship at sea. On a +clear day a keen eye may discern the mast and sails rising +gradually above the horizon, to be followed in due course by the +hull. Similarly, on approaching the shore, high objects become +visible before those that lie nearer the water. It is at least a +plausible supposition that Pythagoras may have made such +observations as these during the voyage in question, and that +therein may lie the germ of that wonderful conception of the +world as a sphere. + +To what extent further proof, based on the fact that the earth's +shadow when the moon is eclipsed is always convex, may have been +known to Pythagoras we cannot say. There is no proof that any of +the Italic philosophers made extensive records of astronomical +observations as did the Egyptians and Babylonians; but we must +constantly recall that the writings of classical antiquity have +been almost altogether destroyed. The absence of astronomical +records is, therefore, no proof that such records never existed. +Pythagoras, it should be said, is reported to have travelled in +Egypt, and he must there have gained an inkling of astronomical +methods. Indeed, he speaks of himself specifically, in a letter +quoted by Diogenes, as one who is accustomed to study astronomy. +Yet a later sentence of the letter, which asserts that the +philosopher is not always occupied about speculations of his own +fancy, suggesting, as it does, the dreamer rather than the +observer, gives us probably a truer glimpse into the +philosopher's mind. There is, indeed, reason to suppose that the +doctrine of the sphericity of the earth appealed to Pythagoras +chiefly because it accorded with his conception that the sphere +is the most perfect solid, just as the circle is the most perfect +plane surface. Be that as it may, the fact remains that we have +here, as far as we can trace its origin, the first expression of +the scientific theory that the earth is round. Had the Italic +philosophers accomplished nothing more than this, their +accomplishment would none the less mark an epoch in the progress +of thought. + +That Pythagoras was an observer of the heavens is further +evidenced by the statement made by Diogenes, on the authority of +Parmenides, that Pythagoras was the first person who discovered +or asserted the identity of Hesperus and Lucifer--that is to say, +of the morning and the evening star. This was really a remarkable +discovery, and one that was no doubt instrumental later on in +determining that theory of the mechanics of the heavens which we +shall see elaborated presently. To have made such a discovery +argues again for the practicality of the mind of Pythagoras. His, +indeed, would seem to have been a mind in which practical +common-sense was strangely blended with the capacity for wide and +imaginative generalization. As further evidence of his +practicality, it is asserted that he was the first person who +introduced measures and weights among the Greeks, this assertion +being made on the authority of Aristoxenus. It will be observed +that he is said to have introduced, not to have invented, weights +and measures, a statement which suggests a knowledge on the part +of the Greeks that weights and measures were previously employed +in Egypt and Babylonia. + +The mind that could conceive the world as a sphere and that +interested itself in weights and measures was, obviously, a mind +of the visualizing type. It is characteristic of this type of +mind to be interested in the tangibilities of geometry, hence it +is not surprising to be told that Pythagoras "carried that +science to perfection." The most famous discovery of Pythagoras +in this field was that the square of the hypotenuse of a +right-angled triangle is equal to the squares of the other sides +of the triangle. We have already noted the fable that his +enthusiasm over this discovery led him to sacrifice a hecatomb. +Doubtless the story is apocryphal, but doubtless, also, it +expresses the truth as to the fervid joy with which the +philosopher must have contemplated the results of his creative +imagination. + +No line alleged to have been written by Pythagoras has come down +to us. We are told that he refrained from publishing his +doctrines, except by word of mouth. "The Lucanians and the +Peucetians, and the Messapians and the Romans," we are assured, +"flocked around him, coming with eagerness to hear his +discourses; no fewer than six hundred came to him every night; +and if any one of them had ever been permitted to see the master, +they wrote of it to their friends as if they had gained some +great advantage." Nevertheless, we are assured that until the +time of Philolaus no doctrines of Pythagoras were ever published, +to which statement it is added that "when the three celebrated +books were published, Plato wrote to have them purchased for him +for a hundred minas."[2] But if such books existed, they are lost +to the modern world, and we are obliged to accept the assertions +of relatively late writers as to the theories of the great +Crotonian. + +Perhaps we cannot do better than quote at length from an +important summary of the remaining doctrines of Pythagoras, which +Diogenes himself quoted from the work of a predecessor.[3] +Despite its somewhat inchoate character, this summary is a most +remarkable one, as a brief analysis of its contents will show. It +should be explained that Alexander (whose work is now lost) is +said to have found these dogmas set down in the commentaries of +Pythagoras. If this assertion be accepted, we are brought one +step nearer the philosopher himself. The summary is as follows: + + +"That the monad was the beginning of everything. From the monad +proceeds an indefinite duad, which is subordinate to the monad as +to its cause. That from the monad and the indefinite duad proceed +numbers. And from numbers signs. And from these last, lines of +which plane figures consist. And from plane figures are derived +solid bodies. And from solid bodies sensible bodies, of which +last there are four elements--fire, water, earth, and air. And +that the world, which is indued with life and intellect, and +which is of a spherical figure, having the earth, which is also +spherical, and inhabited all over in its centre,[4] results from +a combination of these elements, and derives its motion from +them; and also that there are antipodes, and that what is below, +as respects us, is above in respect of them. + +"He also taught that light and darkness, and cold and heat, and +dryness and moisture, were equally divided in the world; and that +while heat was predominant it was summer; while cold had the +mastery, it was winter; when dryness prevailed, it was spring; +and when moisture preponderated, winter. And while all these +qualities were on a level, then was the loveliest season of the +year; of which the flourishing spring was the wholesome period, +and the season of autumn the most pernicious one. Of the day, he +said that the flourishing period was the morning, and the fading +one the evening; on which account that also was the least healthy +time. + +"Another of his theories was that the air around the earth was +immovable and pregnant with disease, and that everything in it +was mortal; but that the upper air was in perpetual motion, and +pure and salubrious, and that everything in that was immortal, +and on that account divine. And that the sun and the moon and the +stars were all gods; for in them the warm principle predominates +which is the cause of life. And that the moon derives its light +from the sun. And that there is a relationship between men and +the gods, because men partake of the divine principle; on which +account, also, God exercises his providence for our advantage. +Also, that Fate is the cause of the arrangement of the world both +generally and particularly. Moreover, that a ray from the sun +penetrated both the cold aether and the dense aether; and they +call the air the cold aether, and the sea and moisture they call +the dense aether. And this ray descends into the depths, and in +this way vivifies everything. And everything which partakes of +the principle of heat lives, on which account, also, plants are +animated beings; but that all living things have not necessarily +souls. And that the soul is a something tom off from the aether, +both warm and cold, from its partaking of the cold aether. And +that the soul is something different from life. Also, that it is +immortal, because that from which it has been detached is +immortal. + +"Also, that animals are born from one another by seeds, and that +it is impossible for there to be any spontaneous production by +the earth. And that seed is a drop from the brain which contains +in itself a warm vapor; and that when this is applied to the womb +it transmits virtue and moisture and blood from the brain, from +which flesh and sinews and bones and hair and the whole body are +produced. And from the vapor is produced the soul, and also +sensation. And that the infant first becomes a solid body at the +end of forty days; but, according to the principles of harmony, +it is not perfect till seven, or perhaps nine, or at most ten +months, and then it is brought forth. And that it contains in +itself all the principles of life, which are all connected +together, and by their union and combination form a harmonious +whole, each of them developing itself at the appointed time. + +"The senses in general, and especially the sight, are a vapor of +excessive warmth, and on this account a man is said to see +through air and through water. For the hot principle is opposed +by the cold one; since, if the vapor in the eyes were cold, it +would have the same temperature as the air, and so would be +dissipated. As it is, in some passages he calls the eyes the +gates of the sun; and he speaks in a similar manner of hearing +and of the other senses. + +"He also says that the soul of man is divided into three parts: +into intuition and reason and mind, and that the first and last +divisions are found also in other animals, but that the middle +one, reason, is only found in man. And that the chief abode of +the soul is in those parts of the body which are between the +heart and the brain. And that that portion of it which is in the +heart is the mind; but that deliberation and reason reside in the +brain. + +Moreover, that the senses are drops from them; and that the +reasoning sense is immortal, but the others are mortal. And that +the soul is nourished by the blood; and that reasons are the +winds of the soul. That it is invisible, and so are its reasons, +since the aether itself is invisible. That the links of the soul +are the veins and the arteries and the nerves. But that when it +is vigorous, and is by itself in a quiescent state, then its +links are words and actions. That when it is cast forth upon the +earth it wanders about, resembling the body. Moreover, that +Mercury is the steward of the souls, and that on this account he +has the name of Conductor, and Commercial, and Infernal, since it +is he who conducts the souls from their bodies, and from earth +and sea; and that he conducts the pure souls to the highest +region, and that he does not allow the impure ones to approach +them, nor to come near one another, but commits them to be bound +in indissoluble fetters by the Furies. The Pythagoreans also +assert that the whole air is full of souls, and that these are +those which are accounted daemons and heroes. Also, that it is by +them that dreams are sent among men, and also the tokens of +disease and health; these last, too, being sent not only to men, +but to sheep also, and other cattle. Also that it is they who are +concerned with purifications and expiations and all kinds of +divination and oracular predictions, and things of that kind."[5] + + +A brief consideration of this summary of the doctrines of +Pythagoras will show that it at least outlines a most +extraordinary variety of scientific ideas. (1) There is suggested +a theory of monads and the conception of the development from +simple to more complex bodies, passing through the stages of +lines, plain figures, and solids to sensible bodies. (2) The +doctrine of the four elements--fire, water, earth, and air--as +the basis of all organisms is put forward. (3) The idea, not +merely of the sphericity of the earth, but an explicit conception +of the antipodes, is expressed. (4) A conception of the sanitary +influence of the air is clearly expressed. (5) An idea of the +problems of generation and heredity is shown, together with a +distinct disavowal of the doctrine of spontaneous generation-- a +doctrine which, it may be added, remained in vogue, nevertheless, +for some twenty-four hundred years after the time of Pythagoras. +(6) A remarkable analysis of mind is made, and a distinction +between animal minds and the human mind is based on this +analysis. The physiological doctrine that the heart is the organ +of one department of mind is offset by the clear statement that +the remaining factors of mind reside in the brain. This early +recognition of brain as the organ of mind must not be forgotten +in our later studies. It should be recalled, however, that a +Crotonian physician, Alemaean, a younger contemporary of +Pythagoras, is also credited with the same theory. (7) A +knowledge of anatomy is at least vaguely foreshadowed in the +assertion that veins, arteries, and nerves are the links of the +soul. In this connection it should be recalled that Pythagoras +was a practical physician. + +As against these scientific doctrines, however, some of them +being at least remarkable guesses at the truth, attention must be +called to the concluding paragraph of our quotation, in which the +old familiar daemonology is outlined, quite after the Oriental +fashion. We shall have occasion to say more as to this phase of +the subject later on. Meantime, before leaving Pythagoras, let us +note that his practical studies of humanity led him to assert the +doctrine that "the property of friends is common, and that +friendship is equality." His disciples, we are told, used to put +all their possessions together in one store and use them in +common. Here, then, seemingly, is the doctrine of communism put +to the test of experiment at this early day. If it seem that +reference to this carries us beyond the bounds of science, it may +be replied that questions such as this will not lie beyond the +bounds of the science of the near future. + + +XENOPHANES AND PARMENIDES + +There is a whimsical tale about Pythagoras, according to which +the philosopher was wont to declare that in an earlier state he +had visited Hades, and had there seen Homer and Hesiod tortured +because of the absurd things they had said about the gods. +Apocrypbal or otherwise, the tale suggests that Pythagoras was an +agnostic as regards the current Greek religion of his time. The +same thing is perhaps true of most of the great thinkers of this +earliest period. But one among them was remembered in later times +as having had a peculiar aversion to the anthropomorphic +conceptions of his fellows. This was Xenophanes, who was born at +Colophon probably about the year 580 B.C., and who, after a life +of wandering, settled finally in Italy and became the founder of +the so-called Eleatic School. + +A few fragments of the philosophical poem in which Xenophanes +expressed his views have come down to us, and these fragments +include a tolerably definite avowal of his faith. "God is one +supreme among gods and men, and not like mortals in body or in +mind," says Xenophanes. Again he asserts that "mortals suppose +that the gods are born (as they themselves are), that they wear +man's clothing and have human voice and body; but," he continues, +"if cattle or lions had hands so as to paint with their hands and +produce works of art as men do, they would paint their gods and +give them bodies in form like their own--horses like horses, +cattle like cattle." Elsewhere he says, with great acumen: "There +has not been a man, nor will there be, who knows distinctly what +I say about the gods or in regard to all things. For even if one +chance for the most part to say what is true, still he would not +know; but every one thinks that he knows."[6] + +In the same spirit Xenophanes speaks of the battles of Titans, of +giants, and of centaurs as "fictions of former ages." All this +tells of the questioning spirit which distinguishes the +scientific investigator. Precisely whither this spirit led him we +do not know, but the writers of a later time have preserved a +tradition regarding a belief of Xenophanes that perhaps entitles +him to be considered the father of geology. Thus Hippolytus +records that Xenophanes studied the fossils to be found in +quarries, and drew from their observation remarkable conclusions. +His words are as follows: "Xenophanes believes that once the +earth was mingled with the sea, but in the course of time it +became freed from moisture; and his proofs are such as these: +that shells are found in the midst of the land and among the +mountains, that in the quarries of Syracuse the imprints of a +fish and of seals had been found, and in Paros the imprint of an +anchovy at some depth in the stone, and in Melite shallow +impressions of all sorts of sea products. He says that these +imprints were made when everything long ago was covered with mud, +and then the imprint dried in the mud. Further, he says that all +men will be destroyed when the earth sinks into the sea and +becomes mud, and that the race will begin anew from the +beginning; and this transformation takes place for all +worlds."[7] Here, then, we see this earliest of paleontologists +studying the fossil-bearing strata of the earth, and drawing from +his observations a marvellously scientific induction. Almost two +thousand years later another famous citizen of Italy, Leonardo da +Vinci, was independently to think out similar conclusions from +like observations. But not until the nineteenth century of our +era, some twenty-four hundred years after the time of Xenophanes, +was the old Greek's doctrine to be accepted by the scientific +world. The ideas of Xenophanes were known to his contemporaries +and, as we see, quoted for a few centuries by his successors, +then they were ignored or quite forgotten; and if any philosopher +of an ensuing age before the time of Leonardo championed a like +rational explanation of the fossils, we have no record of the +fact. The geological doctrine of Xenophanes, then, must be listed +among those remarkable Greek anticipations of nineteenth -century +science which suffered almost total eclipse in the intervening +centuries. + +Among the pupils of Xenophanes was Parmenides, the thinker who +was destined to carry on the work of his master along the same +scientific lines, though at the same time mingling his scientific +conceptions with the mysticism of the poet. We have already had +occasion to mention that Parmenides championed the idea that the +earth is round; noting also that doubts exist as to whether he or +Pythagoras originated this doctrine. No explicit answer to this +question can possibly be hoped for. It seems clear, however, that +for a long time the Italic School, to which both these +philosophers belonged, had a monopoly of the belief in question. +Parmenides, like Pythagoras, is credited with having believed in +the motion of the earth, though the evidence furnished by the +writings of the philosopher himself is not as demonstrative as +one could wish. Unfortunately, the copyists of a later age were +more concerned with metaphysical speculations than with more +tangible things. But as far as the fragmentary references to the +ideas of Parmenides may be accepted, they do not support the idea +of the earth's motion. Indeed, Parmenides is made to say +explicitly, in preserved fragments, that "the world is immovable, +limited, and spheroidal in form."[8] + +Nevertheless, some modern interpreters have found an opposite +meaning in Parmenides. Thus Ritter interprets him as supposing +"that the earth is in the centre spherical, and maintained in +rotary motion by its equiponderance; around it lie certain rings, +the highest composed of the rare element fire, the next lower a +compound of light and darkness, and lowest of all one wholly of +night, which probably indicated to his mind the surface of the +earth, the centre of which again he probably considered to be +fire."[9] But this, like too many interpretations of ancient +thought, appears to read into the fragments ideas which the words +themselves do not warrant. There seems no reason to doubt, +however, that Parmenides actually held the doctrine of the +earth's sphericity. Another glimpse of his astronomical doctrines +is furnished us by a fragment which tells us that he conceived +the morning and the evening stars to be the same, a doctrine +which, as we have seen, was ascribed also to Pythagoras. Indeed, +we may repeat that it is quite impossible to distinguish between +the astronomical doctrines of these two philosophers. + +The poem of Parmenides in which the cosmogonic speculations occur +treats also of the origin of man. The author seems to have had a +clear conception that intelligence depends on bodily organism, +and that the more elaborately developed the organism the higher +the intelligence. But in the interpretation of this thought we +are hampered by the characteristic vagueness of expression, which +may best be evidenced by putting before the reader two English +translations of the same stanza. Here is Ritter's rendering, as +made into English by his translator, Morrison: + + "For exactly as each has the state of his limbs many-jointed, +So invariably stands it with men in their mind and their +reason; For the system of limbs is that which thinketh in +mankind Alike in all and in each: for thought is the +fulness."[10] + +The same stanza is given thus by George Henry Lewes: + + "Such as to each man is the nature of his many-jointed limbs, +Such also is the intelligence of each man; for it is The nature +of limbs (organization) which thinketh in men, Both in one and +in all; for the highest degree of organization gives the +highest degree of thought."[11] + + +Here it will be observed that there is virtual agreement between +the translators except as to the last clause, but that clause is +most essential. The Greek phrase is <gr to gar pleon esti nohma>. +Ritter, it will be observed, renders this, "for thought is the +fulness." Lewes paraphrases it, "for the highest degree of +organization gives the highest degree of thought." The difference +is intentional, since Lewes himself criticises the translation of +Ritter. Ritter's translation is certainly the more literal, but +the fact that such diversity is possible suggests one of the +chief elements of uncertainty that hamper our interpretation of +the thought of antiquity. Unfortunately, the mind of the +commentator has usually been directed towards such subtleties, +rather than towards the expression of precise knowledge. Hence it +is that the philosophers of Greece are usually thought of as mere +dreamers, and that their true status as scientific discoverers is +so often overlooked. With these intangibilities we have no +present concern beyond this bare mention; for us it suffices to +gain as clear an idea as we may of the really scientific +conceptions of these thinkers, leaving the subtleties of their +deductive reasoning for the most part untouched. + + +EMPEDOCLES + +The latest of the important pre-Socratic philosophers of the +Italic school was Empedocles, who was born about 494 B.C. and +lived to the age of sixty. These dates make Empedocles strictly +contemporary with Anaxagoras, a fact which we shall do well to +bear in mind when we come to consider the latter's philosophy in +the succeeding chapter. Like Pythagoras, Empedocles is an +imposing figure. Indeed, there is much of similarity between the +personalities, as between the doctrines, of the two men. +Empedocles, like Pythagoras, was a physician; like him also he +was the founder of a cult. As statesman, prophet, physicist, +physician, reformer, and poet he showed a versatility that, +coupled with profundity, marks the highest genius. In point of +versatility we shall perhaps hardly find his equal at a later +day--unless, indeed, an exception be made of Eratosthenes. The +myths that have grown about the name of Empedocles show that he +was a remarkable personality. He is said to have been an +awe-inspiring figure, clothing himself in Oriental splendor and +moving among mankind as a superior being. Tradition has it that +he threw himself into the crater of a volcano that his otherwise +unexplained disappearance might lead his disciples to believe +that he had been miraculously translated; but tradition goes on +to say that one of the brazen slippers of the philosopher was +thrown up by the volcano, thus revealing his subterfuge. Another +tradition of far more credible aspect asserts that Empedocles +retreated from Italy, returning to the home of his fathers in +Peloponnesus to die there obscurely. It seems odd that the facts +regarding the death of so great a man, at so comparatively late a +period, should be obscure; but this, perhaps, is in keeping with +the personality of the man himself. His disciples would hesitate +to ascribe a merely natural death to so inspired a prophet. + +Empedocles appears to have been at once an observer and a +dreamer. He is credited with noting that the pressure of air will +sustain the weight of water in an inverted tube; with divining, +without the possibility of proof, that light has actual motion in +space; and with asserting that centrifugal motion must keep the +heavens from falling. He is credited with a great sanitary feat +in the draining of a marsh, and his knowledge of medicine was +held to be supernatural. Fortunately, some fragments of the +writings of Empedocles have come down to us, enabling us to judge +at first hand as to part of his doctrines; while still more is +known through the references made to him by Plato, Aristotle, and +other commentators. Empedocles was a poet whose verses stood the +test of criticism. In this regard he is in a like position with +Parmenides; but in neither case are the preserved fragments +sufficient to enable us fully to estimate their author's +scientific attainments. Philosophical writings are obscure enough +at the best, and they perforce become doubly so when expressed in +verse. Yet there are certain passages of Empedocles that are +unequivocal and full of interest. Perhaps the most important +conception which the works of Empedocles reveal to us is the +denial of anthropomorphism as applied to deity. We have seen how +early the anthropomorphic conception was developed and how +closely it was all along clung to; to shake the mind free from it +then was a remarkable feat, in accomplishing which Empedocles +took a long step in the direction of rationalism. His conception +is paralleled by that of another physician, Alcmaeon, of Proton, +who contended that man's ideas of the gods amounted to mere +suppositions at the very most. A rationalistic or sceptical +tendency has been the accompaniment of medical training in all +ages. + +The words in which Empedocles expresses his conception of deity +have been preserved and are well worth quoting: "It is not +impossible," he says, "to draw near (to god) even with the eyes +or to take hold of him with our hands, which in truth is the best +highway of persuasion in the mind of man; for he has no human +head fitted to a body, nor do two shoots branch out from the +trunk, nor has he feet, nor swift legs, nor hairy parts, but he +is sacred and ineffable mind alone, darting through the whole +world with swift thoughts."[8] + +How far Empedocles carried his denial of anthropomorphism is +illustrated by a reference of Aristotle, who asserts "that +Empedocles regards god as most lacking in the power of +perception; for he alone does not know one of the elements, +Strife (hence), of perishable things." It is difficult to avoid +the feeling that Empedocles here approaches the modern +philosophical conception that God, however postulated as +immutable, must also be postulated as unconscious, since +intelligence, as we know it, is dependent upon the transmutations +of matter. But to urge this thought would be to yield to that +philosophizing tendency which has been the bane of interpretation +as applied to the ancient thinkers. + +Considering for a moment the more tangible accomplishments of +Empedocles, we find it alleged that one of his "miracles" +consisted of the preservation of a dead body without putrefaction +for some weeks after death. We may assume from this that he had +gained in some way a knowledge of embalming. As he was +notoriously fond of experiment, and as the body in question +(assuming for the moment the authenticity of the legend) must +have been preserved without disfigurement, it is conceivable even +that he had hit upon the idea of injecting the arteries. This, of +course, is pure conjecture; yet it finds a certain warrant, both +in the fact that the words of Pythagoras lead us to believe that +the arteries were known and studied, and in the fact that +Empedocles' own words reveal him also as a student of the +vascular system. Thus Plutarch cites Empedocles as believing +"that the ruling part is not in the head or in the breast, but in +the blood; wherefore in whatever part of the body the more of +this is spread in that part men excel."[13] And Empedocles' own +words, as preserved by Stobaeus, assert "(the heart) lies in seas +of blood which dart in opposite directions, and there most of all +intelligence centres for men; for blood about the heart is +intelligence in the case of man." All this implies a really +remarkable appreciation of the dependence of vital activities +upon the blood. + +This correct physiological conception, however, was by no means +the most remarkable of the ideas to which Empedoeles was led by +his anatomical studies. His greatest accomplishment was to have +conceived and clearly expressed an idea which the modern +evolutionist connotes when he speaks of homologous parts--an idea +which found a famous modern expositor in Goethe, as we shall see +when we come to deal with eighteenth-century science. Empedocles +expresses the idea in these words: "Hair, and leaves, and thick +feathers of birds, are the same thing in origin, and reptile +scales too on strong limbs. But on hedgehogs sharp-pointed hair +bristles on their backs."[14] That the idea of transmutation of +parts, as well as of mere homology, was in mind is evidenced by a +very remarkable sentence in which Aristotle asserts, "Empedocles +says that fingernails rise from sinew from hardening." Nor is +this quite all, for surely we find the germ of the Lamarckian +conception of evolution through the transmission of acquired +characters in the assertion that "many characteristics appear in +animals because it happened to be thus in their birth, as that +they have such a spine because they happen to be descended from +one that bent itself backward."[15] Aristotle, in quoting this +remark, asserts, with the dogmatism which characterizes the +philosophical commentators of every age, that "Empedocles is +wrong," in making this assertion; but Lamarck, who lived +twenty-three hundred years after Empedocles, is famous in the +history of the doctrine of evolution for elaborating this very +idea. + +It is fair to add, however, that the dreamings of Empedocles +regarding the origin of living organisms led him to some +conceptions that were much less luminous. On occasion, Empedocles +the poet got the better of Empedocles the scientist, and we are +presented with a conception of creation as grotesque as that +which delighted the readers of Paradise Lost at a later day. +Empedocles assures us that "many heads grow up without necks, and +arms were wandering about, necks bereft of shoulders, and eyes +roamed about alone with no foreheads."[16] This chaotic +condition, so the poet dreamed, led to the union of many +incongruous parts, producing "creatures with double faces, +offspring of oxen with human faces, and children of men with oxen +heads." But out of this chaos came, finally, we are led to infer, +a harmonious aggregation of parts, producing ultimately the +perfected organisms that we see. Unfortunately the preserved +portions of the writings of Empedocles do not enlighten us as to +the precise way in which final evolution was supposed to be +effected; although the idea of endless experimentation until +natural selection resulted in survival of the fittest seems not +far afield from certain of the poetical assertions. Thus: "As +divinity was mingled yet more with divinity, these things (the +various members) kept coming together in whatever way each might +chance." Again: "At one time all the limbs which form the body +united into one by love grew vigorously in the prime of life; but +yet at another time, separated by evil Strife, they wander each +in different directions along the breakers of the sea of life. +Just so is it with plants, and with fishes dwelling in watery +halls, and beasts whose lair is in the mountains, and birds borne +on wings."[17] + +All this is poetry rather than science, yet such imaginings could +come only to one who was groping towards what we moderns should +term an evolutionary conception of the origins of organic life; +and however grotesque some of these expressions may appear, it +must be admitted that the morphological ideas of Empedocles, as +above quoted, give the Sicilian philosopher a secure place among +the anticipators of the modern evolutionist. + + + +VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +We have travelled rather far in our study of Greek science, and +yet we have not until now come to Greece itself. And even now, +the men whose names we are to consider were, for the most part, +born in out- lying portions of the empire; they differed from the +others we have considered only in the fact that they were drawn +presently to the capital. The change is due to a most interesting +sequence of historical events. In the day when Thales and his +immediate successors taught in Miletus, when the great men of the +Italic school were in their prime, there was no single undisputed +Centre of Greek influence. The Greeks were a disorganized company +of petty nations, welded together chiefly by unity of speech; but +now, early in the fifth century B.C., occurred that famous attack +upon the Western world by the Persians under Darius and his son +and successor Xerxes. A few months of battling determined the +fate of the Western world. The Orientals were hurled back; the +glorious memories of Marathon, Salamis, and Plataea stimulated +the patriotism and enthusiasm of all children of the Greek race. +The Greeks, for the first time, occupied the centre of the +historical stage; for the brief interval of about half a century +the different Grecian principalities lived together in relative +harmony. One city was recognized as the metropolis of the loosely +bound empire; one city became the home of culture and the Mecca +towards which all eyes turned; that city, of course, was Athens. +For a brief time all roads led to Athens, as, at a later date, +they all led to Rome. The waterways which alone bound the widely +scattered parts of Hellas into a united whole led out from Athens +and back to Athens, as the spokes of a wheel to its hub. Athens +was the commercial centre, and, largely for that reason, it +became the centre of culture and intellectual influence also. The +wise men from the colonies visited the metropolis, and the wise +Athenians went out to the colonies. Whoever aspired to become a +leader in politics, in art, in literature, or in philosophy, made +his way to the capital, and so, with almost bewildering +suddenness, there blossomed the civilization of the age of +Pericles; the civilization which produced aeschylus, Sophocles, +Euripides, Herodotus, and Thucydides; the civilization which made +possible the building of the Parthenon. + + +ANAXAGORAS + +Sometime during the early part of this golden age there came to +Athens a middle-aged man from Clazomenae, who, from our present +stand-point, was a more interesting personality than perhaps any +other in the great galaxy of remarkable men assembled there. The +name of this new-comer was Anaxagoras. It was said in after-time, +we know not with what degree of truth, that he had been a pupil +of Anaximenes. If so, he was a pupil who departed far from the +teachings of his master. What we know for certain is that +Anaxagoras was a truly original thinker, and that he became a +close friend--in a sense the teacher--of Pericles and of +Euripides. Just how long he remained at Athens is not certain; +but the time came when he had made himself in some way +objectionable to the Athenian populace through his teachings. +Filled with the spirit of the investigator, he could not accept +the current conceptions as to the gods. He was a sceptic, an +innovator. Such men are never welcome; they are the chief factors +in the progress of thought, but they must look always to +posterity for recognition of their worth; from their +contemporaries they receive, not thanks, but persecution. +Sometimes this persecution takes one form, sometimes another; to +the credit of the Greeks be it said, that with them it usually +led to nothing more severe than banishment. In the case of +Anaxagoras, it is alleged that the sentence pronounced was death; +but that, thanks to the influence of Pericles, this sentence was +commuted to banishment. In any event, the aged philosopher was +sent away from the city of his adoption. He retired to Lampsacus. +"It is not I that have lost the Athenians," he said; "it is the +Athenians that have lost me." + +The exact position which Anaxagoras had among his contemporaries, +and his exact place in the development of philosophy, have always +been somewhat in dispute. It is not known, of a certainty, that +he even held an open school at Athens. Ritter thinks it doubtful +that he did. It was his fate to be misunderstood, or +underestimated, by Aristotle; that in itself would have sufficed +greatly to dim his fame--might, indeed, have led to his almost +entire neglect had he not been a truly remarkable thinker. With +most of the questions that have exercised the commentators we +have but scant concern. Following Aristotle, most historians of +philosophy have been metaphysicians; they have concerned +themselves far less with what the ancient thinkers really knew +than with what they thought. A chance using of a verbal quibble, +an esoteric phrase, the expression of a vague mysticism--these +would suffice to call forth reams of exposition. It has been the +favorite pastime of historians to weave their own anachronistic +theories upon the scanty woof of the half- remembered thoughts of +the ancient philosophers. To make such cloth of the imagination +as this is an alluring pastime, but one that must not divert us +here. Our point of view reverses that of the philosophers. We are +chiefly concerned, not with some vague saying of Anaxagoras, but +with what he really knew regarding the phenomena of nature; with +what he observed, and with the comprehensible deductions that he +derived from his observations. In attempting to answer these +inquiries, we are obliged, in part, to take our evidence at +second-hand; but, fortunately, some fragments of writings of +Anaxagoras have come down to us. We are told that he wrote only a +single book. It was said even (by Diogenes) that he was the first +man that ever wrote a work in prose. The latter statement would +not bear too close an examination, yet it is true that no +extensive prose compositions of an earlier day than this have +been preserved, though numerous others are known by their +fragments. Herodotus, "the father of prose," was a slightly +younger contemporary of the Clazomenaean philosopher; not +unlikely the two men may have met at Athens. + +Notwithstanding the loss of the greater part of the writings of +Anaxagoras, however, a tolerably precise account of his +scientific doctrines is accessible. Diogenes Laertius expresses +some of them in very clear and precise terms. We have already +pointed out the uncertainty that attaches to such evidence as +this, but it is as valid for Anaxagoras as for another. If we +reject such evidence, we shall often have almost nothing left; in +accepting it we may at least feel certain that we are viewing the +thinker as his contemporaries and immediate successors viewed +him. Following Diogenes, then, we shall find some remarkable +scientific opinions ascribed to Anaxagoras. "He asserted," we are +told, "that the sun was a mass of burning iron, greater than +Peloponnesus, and that the moon contained houses and also hills +and ravines." In corroboration of this, Plato represents him as +having conjectured the right explanation of the moon's light, and +of the solar and lunar eclipses. He had other astronomical +theories that were more fanciful; thus "he said that the stars +originally moved about in irregular confusion, so that at first +the pole-star, which is continually visible, always appeared in +the zenith, but that afterwards it acquired a certain +declination, and that the Milky Way was a reflection of the light +of the sun when the stars did not appear. The comets he +considered to be a concourse of planets emitting rays, and the +shooting- stars he thought were sparks, as it were, leaping from +the firmament." + +Much of this is far enough from the truth, as we now know it, yet +all of it shows an earnest endeavor to explain the observed +phenomena of the heavens on rational principles. To have +predicated the sun as a great molten mass of iron was indeed a +wonderful anticipation of the results of the modern spectroscope. +Nor can it be said that this hypothesis of Anaxagoras was a +purely visionary guess. It was in all probability a scientific +deduction from the observed character of meteoric stones. +Reference has already been made to the alleged prediction of the +fall of the famous meteor at aegespotomi by Anaxagoras. The +assertion that he actually predicted this fall in any proper +sense of the word would be obviously absurd. Yet the fact that +his name is associated with it suggests that he had studied +similar meteorites, or else that he studied this particular one, +since it is not quite clear whether it was before or after this +fall that he made the famous assertion that space is full of +falling stones. We should stretch the probabilities were we to +assert that Anaxagoras knew that shooting-stars and meteors were +the same, yet there is an interesting suggestiveness in his +likening the shooting-stars to sparks leaping from the firmament, +taken in connection with his observation on meteorites. Be this +as it may, the fact that something which falls from heaven as a +blazing light turns out to be an iron-like mass may very well +have suggested to the most rational of thinkers that the great +blazing light called the sun has the same composition. This idea +grasped, it was a not unnatural extension to conceive the other +heavenly bodies as having the same composition. + +This led to a truly startling thought. Since the heavenly bodies +are of the same composition as the earth, and since they are +observed to be whirling about the earth in space, may we not +suppose that they were once a part of the earth itself, and that +they have been thrown off by the force of a whirling motion? Such +was the conclusion which Anaxagoras reached; such his explanation +of the origin of the heavenly bodies. It was a marvellous guess. +Deduct from it all that recent science has shown to be untrue; +bear in mind that the stars are suns, compared with which the +earth is a mere speck of dust; recall that the sun is parent, not +daughter, of the earth, and despite all these deductions, the +cosmogonic guess of Anaxagoras remains, as it seems to us, one of +the most marvellous feats of human intelligence. It was the first +explanation of the cosmic bodies that could be called, in any +sense, an anticipation of what the science of our own day accepts +as a true explanation of cosmic origins. Moreover, let us urge +again that this was no mere accidental flight of the imagination; +it was a scientific induction based on the only data available; +perhaps it is not too much to say that it was the only scientific +induction which these data would fairly sustain. Of course it is +not for a moment to be inferred that Anaxagoras understood, in +the modern sense, the character of that whirling force which we +call centrifugal. About two thousand years were yet to elapse +before that force was explained as elementary inertia; and even +that explanation, let us not forget, merely sufficed to push back +the barriers of mystery by one other stage; for even in our day +inertia is a statement of fact rather than an explanation. + +But however little Anaxagoras could explain the centrifugal force +on mechanical principles, the practical powers of that force were +sufficiently open to his observation. The mere experiment of +throwing a stone from a sling would, to an observing mind, be +full of suggestiveness. It would be obvious that by whirling the +sling about, the stone which it held would be sustained in its +circling path about the hand in seeming defiance of the earth's +pull, and after the stone had left the sling, it could fly away +from the earth to a distance which the most casual observation +would prove to be proportionate to the speed of its flight. +Extremely rapid motion, then, might project bodies from the +earth's surface off into space; a sufficiently rapid whirl would +keep them there. Anaxagoras conceived that this was precisely +what had occurred. His imagination even carried him a step +farther--to a conception of a slackening of speed, through which +the heavenly bodies would lose their centrifugal force, and, +responding to the perpetual pull of gravitation, would fall back +to the earth, just as the great stone at aegespotomi had been +observed to do. + +Here we would seem to have a clear conception of the idea of +universal gravitation, and Anaxagoras stands before us as the +anticipator of Newton. Were it not for one scientific maxim, we +might exalt the old Greek above the greatest of modern natural +philosophers; but that maxim bids us pause. It is phrased thus, +"He discovers who proves." Anaxagoras could not prove; his +argument was at best suggestive, not demonstrative. He did not +even know the laws which govern falling bodies; much less could +he apply such laws, even had he known them, to sidereal bodies at +whose size and distance he could only guess in the vaguest terms. +Still his cosmogonic speculation remains as perhaps the most +remarkable one of antiquity. How widely his speculation found +currency among his immediate successors is instanced in a passage +from Plato, where Socrates is represented as scornfully answering +a calumniator in these terms: "He asserts that I say the sun is a +stone and the moon an earth. Do you think of accusing Anaxagoras, +Miletas, and have you so low an opinion of these men, and think +them so unskilled in laws, as not to know that the books of +Anaxagoras the Clazomenaean are full of these doctrines. And +forsooth the young men are learning these matters from me which +sometimes they can buy from the orchestra for a drachma, at the +most, and laugh at Socrates if he pretends they are +his-particularly seeing they are so strange." + +The element of error contained in these cosmogonic speculations +of Anaxagoras has led critics to do them something less than +justice. But there is one other astronomical speculation for +which the Clazomenaean philosopher has received full credit. It +is generally admitted that it was he who first found out the +explanation of the phases of the moon; a knowledge that that body +shines only by reflected light, and that its visible forms, +waxing and waning month by month from crescent to disk and from +disk to crescent, merely represent our shifting view of its +sun-illumined face. It is difficult to put ourselves in the place +of the ancient observer and realize how little the appearances +suggest the actual fact. That a body of the same structure as the +earth should shine with the radiance of the moon merely because +sunlight is reflected from it, is in itself a supposition +seemingly contradicted by ordinary experience. It required the +mind of a philosopher, sustained, perhaps, by some experimental +observations, to conceive the idea that what seems so obviously +bright may be in reality dark. The germ of the conception of what +the philosopher speaks of as the noumena, or actualities, back of +phenomena or appearances, had perhaps this crude beginning. +Anaxagoras could surely point to the moon in support of his +seeming paradox that snow, being really composed of water, which +is dark, is in reality black and not white--a contention to which +we shall refer more at length in a moment. + +But there is yet another striking thought connected with this new +explanation of the phases of the moon. The explanation implies +not merely the reflection of light by a dark body, but by a dark +body of a particular form. Granted that reflections are in +question, no body but a spherical one could give an appearance +which the moon presents. The moon, then, is not merely a mass of +earth, it is a spherical mass of earth. Here there were no flaws +in the reasoning of Anaxagoras. By scientific induction he passed +from observation to explanation. A new and most important element +was added to the science of astronomy. + +Looking back from the latter-day stand-point, it would seem as if +the mind of the philosopher must have taken one other step: the +mind that had conceived sun, moon, stars, and earth to be of one +substance might naturally, we should think, have reached out to +the further induction that, since the moon is a sphere, the other +cosmic bodies, including the earth, must be spheres also. But +generalizer as he was, Anaxagoras was too rigidly scientific a +thinker to make this assumption. The data at his command did not, +as he analyzed them, seem to point to this conclusion. We have +seen that Pythagoras probably, and Parmenides surely, out there +in Italy had conceived the idea of the earth's rotundity, but the +Pythagorean doctrines were not rapidly taken up in the mother- +country, and Parmenides, it must be recalled, was a strict +contemporary of Anaxagoras himself. It is no reproach, therefore, +to the Clazomenaean philosopher that he should have held to the +old idea that the earth is flat, or at most a convex disk--the +latter being the Babylonian conception which probably dominated +that Milesian school to which Anaxagoras harked back. + +Anaxagoras may never have seen an eclipse of the moon, and even +if he had he might have reflected that, from certain directions, +a disk may throw precisely the same shadow as a sphere. Moreover, +in reference to the shadow cast by the earth, there was, so +Anaxagoras believed, an observation open to him nightly which, we +may well suppose, was not without influence in suggesting to his +mind the probable shape of the earth. The Milky Way, which +doubtless had puzzled astronomers from the beginnings of history +and which was to continue to puzzle them for many centuries after +the day of Anaxagoras, was explained by the Clazomenaean +philosopher on a theory obviously suggested by the theory of the +moon's phases. Since the earth- like moon shines by reflected +light at night, and since the stars seem obviously brighter on +dark nights, Anaxagoras was but following up a perfectly logical +induction when he propounded the theory that the stars in the +Milky Way seem more numerous and brighter than those of any other +part of the heavens, merely because the Milky Way marks the +shadow of the earth. Of course the inference was wrong, so far as +the shadow of the earth is concerned; yet it contained a part +truth, the force of which was never fully recognized until the +time of Galileo. This consists in the assertion that the +brightness of the Milky Way is merely due to the glow of many +stars. The shadow- theory of Anaxagoras would naturally cease to +have validity so soon as the sphericity of the earth was proved, +and with it, seemingly, fell for the time the companion theory +that the Milky Way is made up of a multitude of stars. + +It has been said by a modern critic[1] that the shadow-theory was +childish in that it failed to note that the Milky Way does not +follow the course of the ecliptic. But this criticism only holds +good so long as we reflect on the true character of the earth as +a symmetrical body poised in space. It is quite possible to +conceive a body occupying the position of the earth with +reference to the sun which would cast a shadow having such a +tenuous form as the Milky Way presents. Such a body obviously +would not be a globe, but a long-drawn-out, attenuated figure. +There is, to be sure, no direct evidence preserved to show that +Anaxagoras conceived the world to present such a figure as this, +but what we know of that philosopher's close-reasoning, logical +mind gives some warrant to the assumption--gratuitous though in a +sense it be-- that the author of the theory of the moon's phases +had not failed to ask himself what must be the form of that +terrestrial body which could cast the tenuous shadow of the Milky +Way. Moreover, we must recall that the habitable earth, as known +to the Greeks of that day, was a relatively narrow band of +territory, stretching far to the east and to the west. + + +Anaxagoras as Meteorologist + +The man who had studied the meteorite of aegospotami, and been +put by it on the track of such remarkable inductions, was, +naturally, not oblivious to the other phenomena of the +atmosphere. Indeed, such a mind as that of Anaxagoras was sure to +investigate all manner of natural phenomena, and almost equally +sure to throw new light on any subject that it investigated. +Hence it is not surprising to find Anaxagoras credited with +explaining the winds as due to the rarefactions of the atmosphere +produced by the sun. This explanation gives Anaxagoras full right +to be called "the father of meteorology," a title which, it may +be, no one has thought of applying to him, chiefly because the +science of meteorology did not make its real beginnings until +some twenty-four hundred years after the death of its first great +votary. Not content with explaining the winds, this prototype of +Franklin turned his attention even to the tipper atmosphere. +"Thunder," he is reputed to have said, "was produced by the +collision of the clouds, and lightning by the rubbing together of +the clouds." We dare not go so far as to suggest that this +implies an association in the mind of Anaxagoras between the +friction of the clouds and the observed electrical effects +generated by the friction of such a substance as amber. To make +such a suggestion doubtless would be to fall victim to the old +familiar propensity to read into Homer things that Homer never +knew. Yet the significant fact remains that Anaxagoras ascribed +to thunder and to lightning their true position as strictly +natural phenomena. For him it was no god that menaced humanity +with thundering voice and the flash of his divine fires from the +clouds. Little wonder that the thinker whose science carried him +to such scepticism as this should have felt the wrath of the +superstitious Athenians. + + +Biological Speculations + +Passing from the phenomena of the air to those of the earth +itself, we learn that Anaxagoras explained an earthquake as being +produced by the returning of air into the earth. We cannot be +sure as to the exact meaning here, though the idea that gases are +imprisoned in the substance of the earth seems not far afield. +But a far more remarkable insight than this would imply was shown +by Anaxagoras when he asserted that a certain amount of air is +contained in water, and that fishes breathe this air. The passage +of Aristotle in which this opinion is ascribed to Anaxagoras is +of sufficient interest to be quoted at length: + +"Democritus, of Abdera," says Aristotle, "and some others, that +have spoken concerning respiration, have determined nothing +concerning other animals, but seem to have supposed that all +animals respire. But Anaxagoras and Diogenes (Apolloniates), who +say that all animals respire, have also endeavored to explain how +fishes, and all those animals that have a hard, rough shell, such +as oysters, mussels, etc., respire. And Anaxagoras, indeed, says +that fishes, when they emit water through their gills, attract +air from the mouth to the vacuum in the viscera from the water +which surrounds the mouth; as if air was inherent in the +water."[2] + +It should be recalled that of the three philosophers thus +mentioned as contending that all animals respire, Anaxagoras was +the elder; he, therefore, was presumably the originator of the +idea. It will be observed, too, that Anaxagoras alone is held +responsible for the idea that fishes respire air through their +gills, "attracting" it from the water. This certainly was one of +the shrewdest physiological guesses of any age, if it be regarded +as a mere guess. With greater justice we might refer to it as a +profound deduction from the principle of the uniformity of +nature. + +In making such a deduction, Anaxagoras was far in advance of his +time as illustrated by the fact that Aristotle makes the citation +we have just quoted merely to add that "such things are +impossible," and to refute these "impossible" ideas by means of +metaphysical reasonings that seemed demonstrative not merely to +himself, but to many generations of his followers. + +We are told that Anaxagoras alleged that all animals were +originally generated out of moisture, heat, and earth particles. +Just what opinion he held concerning man's development we are not +informed. Yet there is one of his phrases which +suggests--without, perhaps, quite proving--that he was an +evolutionist. This phrase asserts, with insight that is fairly +startling, that man is the most intelligent of animals because he +has hands. The man who could make that assertion must, it would +seem, have had in mind the idea of the development of +intelligence through the use of hands-- an idea the full force of +which was not evident to subsequent generations of thinkers until +the time of Darwin. + + +Physical Speculations + +Anaxagoras is cited by Aristotle as believing that "plants are +animals and feel pleasure and pain, inferring this because they +shed their leaves and let them grow again." The idea is fanciful, +yet it suggests again a truly philosophical conception of the +unity of nature. The man who could conceive that idea was but +little hampered by traditional conceptions. He was exercising a +rare combination of the rigidly scientific spirit with the +poetical imagination. He who possesses these gifts is sure not to +stop in his questionings of nature until he has found some +thinkable explanation of the character of matter itself. +Anaxagoras found such an explanation, and, as good luck would +have it, that explanation has been preserved. Let us examine his +reasoning in some detail. We have already referred to the claim +alleged to have been made by Anaxagoras that snow is not really +white, but black. The philosopher explained his paradox, we are +told, by asserting that snow is really water, and that water is +dark, when viewed under proper conditions--as at the bottom of a +well. That idea contains the germ of the Clazomenaean +philosopher's conception of the nature of matter. Indeed, it is +not unlikely that this theory of matter grew out of his +observation of the changing forms of water. He seems clearly to +have grasped the idea that snow on the one hand, and vapor on the +other, are of the same intimate substance as the water from which +they are derived and into which they may be again transformed. +The fact that steam and snow can be changed back into water, and +by simple manipulation cannot be changed into any other +substance, finds, as we now believe, its true explanation in the +fact that the molecular structure, as we phrase it--that is to +say, the ultimate particle of which water is composed, is not +changed, and this is precisely the explanation which Anaxagoras +gave of the same phenomena. For him the unit particle of water +constituted an elementary body, uncreated, unchangeable, +indestructible. This particle, in association with like +particles, constitutes the substance which we call water. The +same particle in association with particles unlike itself, might +produce totally different substances--as, for example, when water +is taken up by the roots of a plant and becomes, seemingly, a +part of the substance of the plant. But whatever the changed +association, so Anaxagoras reasoned, the ultimate particle of +water remains a particle of water still. And what was true of +water was true also, so he conceived, of every other substance. +Gold, silver, iron, earth, and the various vegetables and animal +tissues--in short, each and every one of all the different +substances with which experience makes us familiar, is made up of +unit particles which maintain their integrity in whatever +combination they may be associated. This implies, obviously, a +multitude of primordial particles, each one having an +individuality of its own; each one, like the particle of water +already cited, uncreated, unchangeable, and indestructible. + +Fortunately, we have the philosopher's own words to guide us as +to his speculations here. The fragments of his writings that have +come down to us (chiefly through the quotations of Simplicius) +deal almost exclusively with these ultimate conceptions of his +imagination. In ascribing to him, then, this conception of +diverse, uncreated, primordial elements, which can never be +changed, but can only be mixed together to form substances of the +material world, we are not reading back post-Daltonian knowledge +into the system of Anaxagoras. Here are his words: "The Greeks do +not rightly use the terms 'coming into being' and 'perishing.' +For nothing comes into being, nor, yet, does anything perish; but +there is mixture and separation of things that are. So they would +do right in calling 'coming into being' 'mixture' and 'perishing' +'separation.' For how could hair come from what is not hair? Or +flesh from what is not flesh?" + +Elsewhere he tells us that (at one stage of the world's +development) "the dense, the moist, the cold, the dark, collected +there where now is earth; the rare, the warm, the dry, the +bright, departed towards the further part of the aether. The +earth is condensed out of these things that are separated, for +water is separated from the clouds, and earth from the water; and +from the earth stones are condensed by the cold, and these are +separated farther from the water." Here again the influence of +heat and cold in determining physical qualities is kept +pre-eminently in mind. The dense, the moist, the cold, the dark +are contrasted with the rare, the warm, the dry, and bright; and +the formation of stones is spoken of as a specific condensation +due to the influence of cold. Here, then, we have nearly all the +elements of the Daltonian theory of atoms on the one hand, and +the nebular hypothesis of Laplace on the other. But this is not +quite all. In addition to such diverse elementary particles as +those of gold, water, and the rest, Anaxagoras conceived a +species of particles differing from all the others, not merely as +they differ from one another, but constituting a class by +themselves; particles infinitely smaller than the others; +particles that are described as infinite, self-powerful, mixed +with nothing, but existing alone. That is to say (interpreting +the theory in the only way that seems plausible), these most +minute particles do not mix with the other primordial particles +to form material substances in the same way in which these mixed +with one another. But, on the other hand, these "infinite, +self-powerful, and unmixed" particles commingle everywhere and in +every substance whatever with the mixed particles that go to make +up the substances. + +There is a distinction here, it will be observed, which at once +suggests the modern distinction between physical processes and +chemical processes, or, putting it otherwise, between molecular +processes and atomic processes; but the reader must be guarded +against supposing that Anaxagoras had any such thought as this in +mind. His ultimate mixable particles can be compared only with +the Daltonian atom, not with the molecule of the modern +physicist, and his "infinite, self- powerful, and unmixable" +particles are not comparable with anything but the ether of the +modern physicist, with which hypothetical substance they have +many points of resemblance. But the "infinite, self- powerful, +and unmixed" particles constituting thus an ether-like plenum +which permeates all material structures, have also, in the mind +of Anaxagoras, a function which carries them perhaps a stage +beyond the province of the modern ether. For these "infinite, +self powerful, and unmixed" particles are imbued with, and, +indeed, themselves constitute, what Anaxagoras terms nous, a word +which the modern translator has usually paraphrased as "mind." +Neither that word nor any other available one probably conveys an +accurate idea of what Anaxagoras meant to imply by the word nous. +For him the word meant not merely "mind" in the sense of +receptive and comprehending intelligence, but directive and +creative intelligence as well. Again let Anaxagoras speak for +himself: "Other things include a portion of everything, but nous +is infinite, and self-powerful, and mixed with nothing, but it +exists alone, itself by itself. For if it were not by itself, but +were mixed with anything else, it would include parts of all +things, if it were mixed with anything; for a portion of +everything exists in every thing, as has been said by me before, +and things mingled with it would prevent it from having power +over anything in the same way that it does now that it is alone +by itself. For it is the most rarefied of all things and the +purest, and it has all knowledge in regard to everything and the +greatest power; over all that has life, both greater and less, +nous rules. And nous ruled the rotation of the whole, so that it +set it in rotation in the beginning. First it began the rotation +from a small beginning, then more and more was included in the +motion, and yet more will be included. Both the mixed and the +separated and distinct, all things nous recognized. And whatever +things were to be, and whatever things were, as many as are now, +and whatever things shall be, all these nous arranged in order; +and it arranged that rotation, according to which now rotate +stars and sun and moon and air and aether, now that they are +separated. Rotation itself caused the separation, and the dense +is separated from the rare, the warm from the cold, the bright +from the dark, the dry from the moist. And when nous began to set +things in motion, there was separation from everything that was +in motion, all this was made distinct. The rotation of the things +that were moved and made distinct caused them to be yet more +distinct."[3] + +Nous, then, as Anaxagoras conceives it, is "the most rarefied of +all things, and the purest, and it has knowledge in regard to +everything and the greatest power; over all that has life, both +greater and less, it rules." But these are postulants of +omnipresence and omniscience. In other words, nous is nothing +less than the omnipotent artificer of the material universe. It +lacks nothing of the power of deity, save only that we are not +assured that it created the primordial particles. The creation of +these particles was a conception that for Anaxagoras, as for the +modern Spencer, lay beyond the range of imagination. Nous is the +artificer, working with "uncreated" particles. Back of nous and +the particles lies, for an Anaxagoras as for a Spencer, the +Unknowable. But nous itself is the equivalent of that universal +energy of motion which science recognizes as operating between +the particles of matter, and which the theologist personifies as +Deity. It is Pantheistic deity as Anaxagoras conceives it; his +may be called the first scientific conception of a non- +anthropomorphic god. In elaborating this conception Anaxagoras +proved himself one of the most remarkable scientific dreamers of +antiquity. To have substituted for the Greek Pantheon of +anthropomorphic deities the conception of a non-anthropomorphic +immaterial and ethereal entity, of all things in the world "the +most rarefied and the purest," is to have performed a feat which, +considering the age and the environment in which it was +accomplished, staggers the imagination. As a strictly scientific +accomplishment the great thinker's conception of primordial +elements contained a germ of the truth which was to lie dormant +for 2200 years, but which then, as modified and vitalized by the +genius of Dalton, was to dominate the new chemical science of the +nineteenth century. If there are intimations that the primordial +element of Anaxagoras and of Dalton may turn out in the near +future to be itself a compound, there will still remain the yet +finer particles of the nous of Anaxagoras to baffle the most +subtle analysis of which to-day's science gives us any +pre-vision. All in all, then, the work of Anaxagoras must stand +as that of perhaps the most far-seeing scientific imagination of +pre-Socratic antiquity. + + +LEUCIPPUS AND DEMOCRITUS + +But we must not leave this alluring field of speculation as to +the nature of matter without referring to another scientific +guess, which soon followed that of Anaxagoras and was destined to +gain even wider fame, and which in modern times has been somewhat +unjustly held to eclipse the glory of the other achievement. We +mean, of course, the atomic theory of Leucippus and Democritus. +This theory reduced all matter to primordial elements, called +atoms <gr atoma> because they are by hypothesis incapable of +further division. These atoms, making up the entire material +universe, are in this theory conceived as qualitatively +identical, differing from one another only in size and perhaps in +shape. The union of different-sized atoms in endless combinations +produces the diverse substances with which our senses make us +familiar. + +Before we pass to a consideration of this alluring theory, and +particularly to a comparison of it with the theory of Anaxagoras, +we must catch a glimpse of the personality of the men to whom the +theory owes its origin. One of these, Leucippus, presents so +uncertain a figure as to be almost mythical. Indeed, it was long +questioned whether such a man had actually lived, or whether be +were not really an invention of his alleged disciple, Democritus. +Latterday scholarship, however, accepts him as a real personage, +though knowing scarcely more of him than that he was the author +of the famous theory with which his name was associated. It is +suggested that he was a wanderer, like most philosophers of his +time, and that later in life he came to Abdera, in Thrace, and +through this circumstance became the teacher of Democritus. This +fable answers as well as another. What we really know is that +Democritus himself, through whose writings and teachings the +atomic theory gained vogue, was born in Abdera, about the year +460 B.C.--that is to say, just about the time when his great +precursor, Anaxagoras, was migrating to Athens. Democritus, like +most others of the early Greek thinkers, lives in tradition as a +picturesque figure. It is vaguely reported that he travelled for +a time, perhaps in the East and in Egypt, and that then he +settled down to spend the remainder of his life in Abdera. +Whether or not he visited Athens in the course of his wanderings +we do not know. At Abdera he was revered as a sage, but his +influence upon the practical civilization of the time was not +marked. He was pre-eminently a dreamer and a writer. Like his +confreres of the epoch, he entered all fields of thought. He +wrote voluminously, but, unfortunately, his writings have, for +the most part, perished. The fables and traditions of a later day +asserted that Democritus had voluntarily put out his own eyes +that he might turn his thoughts inward with more concentration. +Doubtless this is fiction, yet, as usual with such fictions, it +contains a germ of truth; for we may well suppose that the +promulgator of the atomic theory was a man whose mind was +attracted by the subtleties of thought rather than by the +tangibilities of observation. Yet the term "laughing +philosopher," which seems to have been universally applied to +Democritus, suggests a mind not altogether withdrawn from the +world of practicalities. + +So much for Democritus the man. Let us return now to his theory +of atoms. This theory, it must be confessed, made no very great +impression upon his contemporaries. It found an expositor, a +little later, in the philosopher Epicurus, and later still the +poet Lucretius gave it popular expression. But it seemed scarcely +more than the dream of a philosopher or the vagary of a poet +until the day when modern science began to penetrate the +mysteries of matter. When, finally, the researches of Dalton and +his followers had placed the atomic theory on a surer footing as +the foundation of modern chemistry, the ideas of the old laughing +philosopher of Abdera, which all along had been half derisively +remembered, were recalled with a new interest. Now it appeared +that these ideas had curiously foreshadowed nineteenth-century +knowledge. It appeared that away back in the fifth century B.C. a +man had dreamed out a conception of the ultimate nature of matter +which had waited all these centuries for corroboration. And now +the historians of philosophy became more than anxious to do +justice to the memory of Democritus. + +It is possible that this effort at poetical restitution has +carried the enthusiast too far. There is, indeed, a curious +suggestiveness in the theory of Democritus; there is +philosophical allurement in his reduction of all matter to a +single element; it contains, it may be, not merely a germ of the +science of the nineteenth-century chemistry, but perhaps the +germs also of the yet undeveloped chemistry of the twentieth +century. Yet we dare suggest that in their enthusiasm for the +atomic theory of Democritus the historians of our generation have +done something less than justice to that philosopher's precursor, +Anaxagoras. And one suspects that the mere accident of a name has +been instrumental in producing this result. Democritus called his +primordial element an atom; Anaxagoras, too, conceived a +primordial element, but he called it merely a seed or thing; he +failed to christen it distinctively. Modern science adopted the +word atom and gave it universal vogue. It owed a debt of +gratitude to Democritus for supplying it the word, but it +somewhat overpaid the debt in too closely linking the new meaning +of the word with its old original one. For, let it be clearly +understood, the Daltonian atom is not precisely comparable with +the atom of Democritus. The atom, as Democritus conceived it, was +monistic; all atoms, according to this hypothesis, are of the +same substance; one atom differs from another merely in size and +shape, but not at all in quality. But the Daltonian hypothesis +conceived, and nearly all the experimental efforts of the +nineteenth century seemed to prove, that there are numerous +classes of atoms, each differing in its very essence from the +others. + +As the case stands to-day the chemist deals with seventy-odd +substances, which he calls elements. Each one of these substances +is, as he conceives it, made up of elementary atoms having a +unique personality, each differing in quality from all the +others. As far as experiment has thus far safely carried us, the +atom of gold is a primordial element which remains an atom of +gold and nothing else, no matter with what other atoms it is +associated. So, too, of the atom of silver, or zinc, or +sodium--in short, of each and every one of the seventy-odd +elements. There are, indeed, as we shall see, experiments that +suggest the dissolution of the atom--that suggest, in short, that +the Daltonian atom is misnamed, being a structure that may, under +certain conditions, be broken asunder. But these experiments +have, as yet, the warrant rather of philosophy than of pure +science, and to-day we demand that the philosophy of science +shall be the handmaid of experiment. + +When experiment shall have demonstrated that the Daltonian atom +is a compound, and that in truth there is but a single true atom, +which, combining with its fellows perhaps in varying numbers and +in different special relations, produces the Daltonian atoms, +then the philosophical theory of monism will have the +experimental warrant which to-day it lacks; then we shall be a +step nearer to the atom of Democritus in one direction, a step +farther away in the other. We shall be nearer, in that the +conception of Democritus was, in a sense, monistic; farther away, +in that all the atoms of Democritus, large and small alike, were +considered as permanently fixed in size. Democritus postulated +all his atoms as of the same substance, differing not at all in +quality; yet he was obliged to conceive that the varying size of +the atoms gave to them varying functions which amounted to +qualitative differences. He might claim for his largest atom the +same quality of substance as for his smallest, but so long as he +conceived that the large atoms, when adjusted together to form a +tangible substance, formed a substance different in quality from +the substance which the small atoms would make up when similarly +grouped, this concession amounts to the predication of difference +of quality between the atoms themselves. The entire question +reduces itself virtually to a quibble over the word quality, So +long as one atom conceived to be primordial and indivisible is +conceded to be of such a nature as necessarily to produce a +different impression on our senses, when grouped with its +fellows, from the impression produced by other atoms when +similarly grouped, such primordial atoms do differ among +themselves in precisely the same way for all practical purposes +as do the primordial elements of Anaxagoras. + +The monistic conception towards which twentieth- century +chemistry seems to be carrying us may perhaps show that all the +so-called atoms are compounded of a single element. All the true +atoms making up that element may then properly be said to have +the same quality, but none the less will it remain true that the +combinations of that element that go to make up the different +Daltonian atoms differ from one another in quality in precisely +the same sense in which such tangible substances as gold, and +oxygen, and mercury, and diamonds differ from one another. In the +last analysis of the monistic philosophy, there is but one +substance and one quality in the universe. In the widest view of +that philosophy, gold and oxygen and mercury and diamonds are one +substance, and, if you please, one quality. But such refinements +of analysis as this are for the transcendental philosopher, and +not for the scientist. Whatever the allurement of such reasoning, +we must for the purpose of science let words have a specific +meaning, nor must we let a mere word-jugglery blind us to the +evidence of facts. That was the rock on which Greek science +foundered; it is the rock which the modern helmsman sometimes +finds it difficult to avoid. And if we mistake not, this case of +the atom of Democritus is precisely a case in point. Because +Democritus said that his atoms did not differ in quality, the +modern philosopher has seen in his theory the essentials of +monism; has discovered in it not merely a forecast of the +chemistry of the nineteenth century, but a forecast of the +hypothetical chemistry of the future. And, on the other hand, +because Anaxagoras predicted a different quality for his +primordial elements, the philosopher of our day has discredited +the primordial element of Anaxagoras. + +Yet if our analysis does not lead us astray, the theory of +Democritus was not truly monistic; his indestructible atoms, +differing from one another in size and shape, utterly incapable +of being changed from the form which they had maintained from the +beginning, were in reality as truly and primordially different as +are the primordial elements of Anaxagoras. In other words, the +atom of Democritus is nothing less than the primordial seed of +Anaxagoras, a little more tangibly visualized and given a +distinctive name. Anaxagoras explicitly conceived his elements as +invisibly small, as infinite in number, and as made up of an +indefinite number of kinds--one for each distinctive substance in +the world. But precisely the same postulates are made of the atom +of Democritus. These also are invisibly small; these also are +infinite in number; these also are made up of an indefinite +number of kinds, corresponding with the observed difference of +substances in the world. "Primitive seeds," or "atoms," were +alike conceived to be primordial, un- changeable, and +indestructible. Wherein then lies the difference? We answer, +chiefly in a name; almost solely in the fact that Anaxagoras did +not attempt to postulate the physical properties of the elements +beyond stating that each has a distinctive personality, while +Democritus did attempt to postulate these properties. He, too, +admitted that each kind of element has its distinctive +personality, and he attempted to visualize and describe the +characteristics of the personality. + +Thus while Anaxagoras tells us nothing of his elements except +that they differ from one another, Democritus postulates a +difference in size, imagines some elements as heavier and some as +lighter, and conceives even that the elements may be provided +with projecting hooks, with the aid of which they link themselves +one with another. No one to-day takes these crude visualizings +seriously as to their details. The sole element of truth which +these dreamings contain, as distinguishing them from the +dreamings of Anaxagoras, is in the conception that the various +atoms differ in size and weight. Here, indeed, is a vague +fore-shadowing of that chemistry of form which began to come into +prominence towards the close of the nineteenth century. To have +forecast even dimly this newest phase of chemical knowledge, +across the abyss of centuries, is indeed a feat to put Democritus +in the front rank of thinkers. But this estimate should not blind +us to the fact that the pre-vision of Democritus was but a slight +elaboration of a theory which had its origin with another +thinker. The association between Anaxagoras and Democritus cannot +be directly traced, but it is an association which the historian +of ideas should never for a moment forget. If we are not to be +misled by mere word-jugglery, we shall recognize the founder of +the atomic theory of matter in Anaxagoras; its expositors along +slightly different lines in Leucippus and Democritus; its +re-discoverer of the nineteenth century in Dalton. All in all, +then, just as Anaxagoras preceded Democritus in time, so must he +take precedence over him also as an inductive thinker, who +carried the use of the scientific imagination to its farthest +reach. + +An analysis of the theories of the two men leads to somewhat the +same conclusion that might be reached from a comparison of their +lives. Anaxagoras was a sceptical, experimental scientist, gifted +also with the prophetic imagination. He reasoned always from the +particular to the general, after the manner of true induction, +and he scarcely took a step beyond the confines of secure +induction. True scientist that he was, he could content himself +with postulating different qualities for his elements, without +pretending to know how these qualities could be defined. His +elements were by hypothesis invisible, hence he would not attempt +to visualize them. Democritus, on the other hand, refused to +recognize this barrier. Where he could not know, he still did not +hesitate to guess. Just as he conceived his atom of a definite +form with a definite structure, even so he conceived that the +atmosphere about him was full of invisible spirits; he accepted +the current superstitions of his time. Like the average Greeks of +his day, he even believed in such omens as those furnished by +inspecting the entrails of a fowl. These chance bits of biography +are weather- vanes of the mind of Democritus. They tend to +substantiate our conviction that Democritus must rank below +Anaxagoras as a devotee of pure science. But, after all, such +comparisons and estimates as this are utterly futile. The +essential fact for us is that here, in the fifth century before +our era, we find put forward the most penetrating guess as to the +constitution of matter that the history of ancient thought has to +present to us. In one direction, the avenue of progress is +barred; there will be no farther step that way till we come down +the centuries to the time of Dalton. + + +HIPPOCRATES AND GREEK MEDICINE + +These studies of the constitution of matter have carried us to +the limits of the field of scientific imagination in antiquity; +let us now turn sharply and consider a department of science in +which theory joins hands with practicality. Let us witness the +beginnings of scientific therapeutics. + +Medicine among the early Greeks, before the time of Hippocrates, +was a crude mixture of religion, necromancy, and mysticism. +Temples were erected to the god of medicine, aesculapius, and +sick persons made their way, or were carried, to these temples, +where they sought to gain the favor of the god by suitable +offerings, and learn the way to regain their health through +remedies or methods revealed to them in dreams by the god. When +the patient had been thus cured, he placed a tablet in the temple +describing his sickness, and telling by what method the god had +cured him. He again made suitable offerings at the temple, which +were sometimes in the form of gold or silver representations of +the diseased organ--a gold or silver model of a heart, hand, +foot, etc. + +Nevertheless, despite this belief in the supernatural, many drugs +and healing lotions were employed, and the Greek physicians +possessed considerable skill in dressing wounds and bandaging. +But they did not depend upon these surgical dressings alone, +using with them certain appropriate prayers and incantations, +recited over the injured member at the time of applying the +dressings. + +Even the very early Greeks had learned something of anatomy. The +daily contact with wounds and broken bones must of necessity lead +to a crude understanding of anatomy in general. The first Greek +anatomist, however, who is recognized as such, is said to have +been Alcmaeon. He is said to have made extensive dissections of +the lower animals, and to have described many hitherto unknown +structures, such as the optic nerve and the Eustachian canal--the +small tube leading into the throat from the ear. He is credited +with many unique explanations of natural phenomena, such as, for +example, the explanation that "hearing is produced by the hollow +bone behind the ear; for all hollow things are sonorous." He was +a rationalist, and he taught that the brain is the organ of mind. +The sources of our information about his work, however, are +unreliable. + +Democedes, who lived in the sixth century B.C., is the first +physician of whom we have any trustworthy history. We learn from +Herodotus that he came from Croton to aegina, where, in +recognition of his skill, he was appointed medical officer of the +city. From aegina he was called to Athens at an increased salary, +and later was in charge of medical affairs in several other Greek +cities. He was finally called to Samos by the tyrant Polycrates, +who reigned there from about 536 to 522 B.C. But on the death of +Polycrates, who was murdered by the Persians, Democedes became a +slave. His fame as a physician, however, had reached the ears of +the Persian monarch, and shortly after his capture he was +permitted to show his skill upon King Darius himself. The Persian +monarch was suffering from a sprained ankle, which his Egyptian +surgeons had been unable to cure. Democedes not only cured the +injured member but used his influence in saving the lives of his +Egyptian rivals, who had been condemned to death by the king. + +At another time he showed his skill by curing the queen, who was +suffering from a chronic abscess of long standing. This so +pleased the monarch that he offered him as a reward anything he +might desire, except his liberty. But the costly gifts of Darius +did not satisfy him so long as he remained a slave; and +determined to secure his freedom at any cost, he volunteered to +lead some Persian spies into his native country, promising to use +his influence in converting some of the leading men of his nation +to the Persian cause. Laden with the wealth that had been heaped +upon him by Darius, he set forth upon his mission, but upon +reaching his native city of Croton he threw off his mask, +renounced his Persian mission, and became once more a free Greek. + +While the story of Democedes throws little light upon the medical +practices of the time, it shows that paid city medical officers +existed in Greece as early as the fifth and sixth centuries B.C. +Even then there were different "schools" of medicine, whose +disciples disagreed radically in their methods of treating +diseases; and there were also specialists in certain diseases, +quacks, and charlatans. Some physicians depended entirely upon +external lotions for healing all disorders; others were +"hydrotherapeutists" or "bath- physicians"; while there were a +host of physicians who administered a great variety of herbs and +drugs. There were also magicians who pretended to heal by +sorcery, and great numbers of bone-setters, oculists, and +dentists. + +Many of the wealthy physicians had hospitals, or clinics, where +patients were operated upon and treated. They were not hospitals +in our modern understanding of the term, but were more like +dispensaries, where patients were treated temporarily, but were +not allowed to remain for any length of time. Certain communities +established and supported these dispensaries for the care of the +poor. + +But anything approaching a rational system of medicine was not +established, until Hippocrates of Cos, the "father of medicine," +came upon the scene. In an age that produced Phidias, Lysias, +Herodotus, Sophocles, and Pericles, it seems but natural that the +medical art should find an exponent who would rise above +superstitious dogmas and lay the foundation for a medical +science. His rejection of the supernatural alone stamps the +greatness of his genius. But, besides this, he introduced more +detailed observation of diseases, and demonstrated the importance +that attaches to prognosis. + +Hippocrates was born at Cos, about 460 B.C., but spent most of +his life at Larissa, in Thessaly. He was educated as a physician +by his father, and travelled extensively as an itinerant +practitioner for several years. His travels in different climates +and among many different people undoubtedly tended to sharpen his +keen sense of observation. He was a practical physician as well +as a theorist, and, withal, a clear and concise writer. "Life is +short," he says, "opportunity fleeting, judgment difficult, +treatment easy, but treatment after thought is proper and +profitable." + +His knowledge of anatomy was necessarily very imperfect, and was +gained largely from his predecessors, to whom he gave full +credit. Dissections of the human body were forbidden him, and he +was obliged to confine his experimental researches to operations +on the lower animals. His knowledge of the structure and +arrangement of the bones, however, was fairly accurate, but the +anatomy of the softer tissues, as he conceived it, was a queer +jumbling together of blood-vessels, muscles, and tendons. He does +refer to "nerves," to be sure, but apparently the structures +referred to are the tendons and ligaments, rather than the nerves +themselves. He was better acquainted with the principal organs in +the cavities of the body, and knew, for example, that the heart +is divided into four cavities, two of which he supposed to +contain blood, and the other two air. + +His most revolutionary step was his divorcing of the supernatural +from the natural, and establishing the fact that disease is due +to natural causes and should be treated accordingly. The effect +of such an attitude can hardly be over-estimated. The +establishment of such a theory was naturally followed by a close +observation as to the course of diseases and the effects of +treatment. To facilitate this, he introduced the custom of +writing down his observations as he made them--the "clinical +history" of the case. Such clinical records are in use all over +the world to-day, and their importance is so obvious that it is +almost incomprehensible that they should have fallen into disuse +shortly after the time of Hippocrates, and not brought into +general use again until almost two thousand years later. + +But scarcely less important than his recognition of disease as a +natural phenomenon was the importance he attributed to prognosis. +Prognosis, in the sense of prophecy, was common before the time +of Hippocrates. But prognosis, as he practised it and as we +understand it to-day, is prophecy based on careful observation of +the course of diseases--something more than superstitious +conjecture. + +Although Hippocratic medicine rested on the belief in natural +causes, nevertheless, dogma and theory held an important place. +The humoral theory of disease was an all-important one, and so +fully was this theory accepted that it influenced the science of +medicine all through succeeding centuries. According to this +celebrated theory there are four humors in the body-- blood, +phlegm, yellow bile, and black bile. When these humors are mixed +in exact proportions they constitute health; but any deviations +from these proportions produce disease. In treating diseases the +aim of the physician was to discover which of these humors were +out of proportion and to restore them to their natural +equilibrium. It was in the methods employed in this restitution, +rather than a disagreement about the humors themselves, that +resulted in the various "schools" of medicine. + +In many ways the surgery of Hippocrates showed a better +understanding of the structure of the organs than of their +functions. Some of the surgical procedures as described by him +are followed, with slight modifications, to-day. Many of his +methods were entirely lost sight of until modern times, and one, +the treatment of dislocation of the outer end of the collar-bone, +was not revived until some time in the eighteenth century. + +Hippocrates, it seems, like modern physicians, sometimes suffered +from the ingratitude of his patients. "The physician visits a +patient suffering from fever or a wound, and prescribes for him," +he says; "on the next day, if the patient feels worse the blame +is laid upon the physician; if, on the other hand, he feels +better, nature is extolled, and the physician reaps no praise." +The essence of this has been repeated in rhyme and prose by +writers in every age and country, but the "father of medicine" +cautions physicians against allowing it to influence their +attitude towards their profession. + + + +VIII. POST-SOCRATIC SCIENCE AT ATHENS--PLATO, ARISTOTLE, AND +THEOPHRASTUS + +Doubtless it has been noticed that our earlier scientists were as +far removed as possible from the limitations of specialism. In +point of fact, in this early day, knowledge had not been +classified as it came to be later on. The philosopher was, as his +name implied, a lover of knowledge, and he did not find it beyond +the reach of his capacity to apply himself to all departments of +the field of human investigation. It is nothing strange to +discover that Anaximander and the Pythagoreans and Anaxagoras +have propounded theories regarding the structure of the cosmos, +the origin and development of animals and man, and the nature of +matter itself. Nowadays, so enormously involved has become the +mass of mere facts regarding each of these departments of +knowledge that no one man has the temerity to attempt to master +them all. But it was different in those days of beginnings. Then +the methods of observation were still crude, and it was quite the +custom for a thinker of forceful personality to find an eager +following among disciples who never thought of putting his +theories to the test of experiment. The great lesson that true +science in the last resort depends upon observation and +measurement, upon compass and balance, had not yet been learned, +though here and there a thinker like Anaxagoras had gained an +inkling of it. + +For the moment, indeed, there in Attica, which was now, thanks to +that outburst of Periclean culture, the centre of the world's +civilization, the trend of thought was to take quite another +direction. The very year which saw the birth of Democritus at +Abdera, and of Hippocrates, marked also the birth, at Athens, of +another remarkable man, whose influence it would scarcely be +possible to over-estimate. This man was Socrates. The main facts +of his history are familiar to every one. It will be recalled +that Socrates spent his entire life in Athens, mingling +everywhere with the populace; haranguing, so the tradition goes, +every one who would listen; inculcating moral lessons, and +finally incurring the disapprobation of at least a voting +majority of his fellow-citizens. He gathered about him a company +of remarkable men with Plato at their head, but this could not +save him from the disapprobation of the multitudes, at whose +hands he suffered death, legally administered after a public +trial. The facts at command as to certain customs of the Greeks +at this period make it possible to raise a question as to whether +the alleged "corruption of youth," with which Socrates was +charged, may not have had a different implication from what +posterity has preferred to ascribe to it. But this thought, +almost shocking to the modern mind and seeming altogether +sacrilegious to most students of Greek philosophy, need not here +detain us; neither have we much concern in the present connection +with any part of the teaching of the martyred philosopher. For +the historian of metaphysics, Socrates marks an epoch, but for +the historian of science he is a much less consequential figure. + +Similarly regarding Plato, the aristocratic Athenian who sat at +the feet of Socrates, and through whose writings the teachings of +the master found widest currency. Some students of philosophy +find in Plato "the greatest thinker and writer of all time."[1] +The student of science must recognize in him a thinker whose +point of view was essentially non-scientific; one who tended +always to reason from the general to the particular rather than +from the particular to the general. Plato's writings covered +almost the entire field of thought, and his ideas were presented +with such literary charm that successive generations of readers +turned to them with unflagging interest, and gave them wide +currency through copies that finally preserved them to our own +time. Thus we are not obliged in his case, as we are in the case +of every other Greek philosopher, to estimate his teachings +largely from hearsay evidence. Plato himself speaks to us +directly. It is true, the literary form which he always adopted, +namely, the dialogue, does not give quite the same certainty as +to when he is expressing his own opinions that a more direct +narrative would have given; yet, in the main, there is little +doubt as to the tenor of his own opinions--except, indeed, such +doubt as always attaches to the philosophical reasoning of the +abstract thinker. + +What is chiefly significant from our present standpoint is that +the great ethical teacher had no significant message to give the +world regarding the physical sciences. He apparently had no +sharply defined opinions as to the mechanism of the universe; no +clear conception as to the origin or development of organic +beings; no tangible ideas as to the problems of physics; no +favorite dreams as to the nature of matter. Virtually his back +was turned on this entire field of thought. He was under the sway +of those innate ideas which, as we have urged, were among the +earliest inductions of science. But he never for a moment +suspected such an origin for these ideas. He supposed his +conceptions of being, his standards of ethics, to lie back of all +experience; for him they were the most fundamental and most +dependable of facts. He criticised Anaxagoras for having tended +to deduce general laws from observation. As we moderns see it, +such criticism is the highest possible praise. It is a criticism +that marks the distinction between the scientist who is also a +philosopher and the philosopher who has but a vague notion of +physical science. Plato seemed, indeed, to realize the value of +scientific investigation; he referred to the astronomical studies +of the Egyptians and Chaldeans, and spoke hopefully of the +results that might accrue were such studies to be taken up by +that Greek mind which, as he justly conceived, had the power to +vitalize and enrich all that it touched. But he told here of what +he would have others do, not of what he himself thought of doing. +His voice was prophetic, but it stimulated no worker of his own +time. + +Plato himself had travelled widely. It is a familiar legend that +he lived for years in Egypt, endeavoring there to penetrate the +mysteries of Egyptian science. It is said even that the rudiments +of geometry which he acquired there influenced all his later +teachings. But be that as it may, the historian of science must +recognize in the founder of the Academy a moral teacher and +metaphysical dreamer and sociologist, but not, in the modern +acceptance of the term, a scientist. Those wider phases of +biological science which find their expression in metaphysics, in +ethics, in political economy, lie without our present scope; and +for the development of those subjects with which we are more +directly concerned, Plato, like his master, has a negative +significance. + + +ARISTOTLE (384-322 B.C.) + +When we pass to that third great Athenian teacher, Aristotle, the +case is far different. Here was a man whose name was to be +received as almost a synonym for Greek science for more than a +thousand years after his death. All through the Middle Ages his +writings were to be accepted as virtually the last word regarding +the problems of nature. We shall see that his followers actually +preferred his mandate to the testimony of their own senses. We +shall see, further, that modern science progressed somewhat in +proportion as it overthrew the Aristotelian dogmas. But the +traditions of seventeen or eighteen centuries are not easily set +aside, and it is perhaps not too much to say that the name of +Aristotle stands, even in our own time, as vaguely representative +in the popular mind of all that was highest and best in the +science of antiquity. Yet, perhaps, it would not be going too far +to assert that something like a reversal of this judgment would +be nearer the truth. Aristotle did, indeed, bring together a +great mass of facts regarding animals in his work on natural +history, which, being preserved, has been deemed to entitle its +author to be called the "father of zoology." But there is no +reason to suppose that any considerable portion of this work +contained matter that was novel, or recorded observations that +were original with Aristotle; and the classifications there +outlined are at best but a vague foreshadowing of the elaboration +of the science. Such as it is, however, the natural history +stands to the credit of the Stagirite. He must be credited, too, +with a clear enunciation of one most important scientific +doctrine--namely, the doctrine of the spherical figure of the +earth. We have already seen that this theory originated with the +Pythagorean philosophers out in Italy. We have seen, too, that +the doctrine had not made its way in Attica in the time of +Anaxagoras. But in the intervening century it had gained wide +currency, else so essentially conservative a thinker as Aristotle +would scarcely have accepted it. He did accept it, however, and +gave the doctrine clearest and most precise expression. Here are +his words:[2] + + +"As to the figure of the earth it must necessarily be +spherical.... If it were not so, the eclipses of the moon would +not have such sections as they have. For in the configurations in +the course of a month the deficient part takes all different +shapes; it is straight, and concave, and convex; but in eclipses +it always has the line of divisions convex; wherefore, since the +moon is eclipsed in consequence of the interposition of the +earth, the periphery of the earth must be the cause of this by +having a spherical form. And again, from the appearance of the +stars it is clear, not only that the earth is round, but that its +size is not very large; for when we make a small removal to the +south or the north, the circle of the horizon becomes palpably +different, so that the stars overhead undergo a great change, and +are not the same to those that travel in the north and to the +south. For some stars are seen in Egypt or at Cyprus, but are not +seen in the countries to the north of these; and the stars that +in the north are visible while they make a complete circuit, +there undergo a setting. So that from this it is manifest, not +only that the form of the earth is round, but also that it is a +part of a not very large sphere; for otherwise the difference +would not be so obvious to persons making so small a change of +place. Wherefore we may judge that those persons who connect the +region in the neighborhood of the pillars of Hercules with that +towards India, and who assert that in this way the sea is one, do +not assert things very improbable. They confirm this conjecture +moreover by the elephants, which are said to be of the same +species towards each extreme; as if this circumstance was a +consequence of the conjunction of the extremes. The +mathematicians who try to calculate the measure of the +circumference, make it amount to four hundred thousand stadia; +whence we collect that the earth is not only spherical, but is +not large compared with the magnitude of the other stars." + +But in giving full meed of praise to Aristotle for the +promulgation of this doctrine of the sphericity of the earth, it +must unfortunately be added that the conservative philosopher +paused without taking one other important step. He could not +accept, but, on the contrary, he expressly repudiated, the +doctrine of the earth's motion. We have seen that this idea also +was a part of the Pythagorean doctrine, and we shall have +occasion to dwell more at length on this point in a succeeding +chapter. It has even been contended by some critics that it was +the adverse conviction of the Peripatetic philosopher which, more +than any other single influence, tended to retard the progress of +the true doctrine regarding the mechanism of the heavens. +Aristotle accepted the sphericity of the earth, and that doctrine +became a commonplace of scientific knowledge, and so continued +throughout classical antiquity. But Aristotle rejected the +doctrine of the earth's motion, and that doctrine, though +promulgated actively by a few contemporaries and immediate +successors of the Stagirite, was then doomed to sink out of view +for more than a thousand years. If it be a correct assumption +that the influence of Aristotle was, in a large measure, +responsible for this result, then we shall perhaps not be far +astray in assuming that the great founder of the Peripatetic +school was, on the whole, more instrumental in retarding the +progress of astronomical science that any other one man that ever +lived. + +The field of science in which Aristotle was pre-eminently a +pathfinder is zoology. His writings on natural history have +largely been preserved, and they constitute by far the most +important contribution to the subject that has come down to us +from antiquity. They show us that Aristotle had gained possession +of the widest range of facts regarding the animal kingdom, and, +what is far more important, had attempted to classify these +facts. In so doing he became the founder of systematic zoology. +Aristotle's classification of the animal kingdom was known and +studied throughout the Middle Ages, and, in fact, remained in +vogue until superseded by that of Cuvier in the nineteenth +century. It is not to be supposed that all the terms of +Aristotle's classification originated with him. Some of the +divisions are too patent to have escaped the observation of his +predecessors. Thus, for example, the distinction between birds +and fishes as separate classes of animals is so obvious that it +must appeal to a child or to a savage. But the efforts of +Aristotle extended, as we shall see, to less patent +generalizations. At the very outset, his grand division of the +animal kingdom into blood-bearing and bloodless animals implies a +very broad and philosophical conception of the entire animal +kingdom. The modern physiologist does not accept the +classification, inasmuch as it is now known that colorless fluids +perform the functions of blood for all the lower organisms. But +the fact remains that Aristotle's grand divisions correspond to +the grand divisions of the Lamarckian system--vertebrates and +invertebrates-- which every one now accepts. Aristotle, as we +have said, based his classification upon observation of the +blood; Lamarck was guided by a study of the skeleton. The fact +that such diverse points of view could direct the observer +towards the same result gives, inferentially, a suggestive lesson +in what the modern physiologist calls the homologies of parts of +the organism. + +Aristotle divides his so-called blood-bearing animals into five +classes: (1) Four-footed animals that bring forth their young +alive; (2) birds; (3) egg-laying four- footed animals (including +what modern naturalists call reptiles and amphibians); (4) whales +and their allies; (5) fishes. This classification, as will be +observed, is not so very far afield from the modern divisions +into mammals, birds, reptiles, amphibians, and fishes. That +Aristotle should have recognized the fundamental distinction +between fishes and the fish- like whales, dolphins, and porpoises +proves the far from superficial character of his studies. +Aristotle knew that these animals breathe by means of lungs and +that they produce living young. He recognized, therefore, their +affinity with his first class of animals, even if he did not, +like the modern naturalist, consider these affinities close +enough to justify bringing the two types together into a single +class. + +The bloodless animals were also divided by Aristotle into five +classes--namely: (1) Cephalopoda (the octopus, cuttle-fish, +etc.); (2) weak-shelled animals (crabs, etc.); (3) insects and +their allies (including various forms, such as spiders and +centipedes, which the modern classifier prefers to place by +themselves); (4) hard-shelled animals (clams, oysters, snails, +etc.); (5) a conglomerate group of marine forms, including +star-fish, sea-urchins, and various anomalous forms that were +regarded as linking the animal to the vegetable worlds. This +classification of the lower forms of animal life continued in +vogue until Cuvier substituted for it his famous grouping into +articulates, mollusks, and radiates; which grouping in turn was +in part superseded later in the nineteenth century. + +What Aristotle did for the animal kingdom his pupil, +Theophrastus, did in some measure for the vegetable kingdom. +Theophrastus, however, was much less a classifier than his +master, and his work on botany, called The Natural History of +Development, pays comparatively slight attention to theoretical +questions. It deals largely with such practicalities as the +making of charcoal, of pitch, and of resin, and the effects of +various plants on the animal organism when taken as foods or as +medicines. In this regard the work of Theophrastus, is more +nearly akin to the natural history of the famous Roman compiler, +Pliny. It remained, however, throughout antiquity as the most +important work on its subject, and it entitles Theophrastus to be +called the "father of botany." Theophrastus deals also with the +mineral kingdom after much the same fashion, and here again his +work is the most notable that was produced in antiquity. + + + +IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + +We are entering now upon the most important scientific epoch of +antiquity. When Aristotle and Theophrastus passed from the scene, +Athens ceased to be in any sense the scientific centre of the +world. That city still retained its reminiscent glory, and cannot +be ignored in the history of culture, but no great scientific +leader was ever again to be born or to take up his permanent +abode within the confines of Greece proper. With almost +cataclysmic suddenness, a new intellectual centre appeared on the +south shore of the Mediterranean. This was the city of +Alexandria, a city which Alexander the Great had founded during +his brief visit to Egypt, and which became the capital of Ptolemy +Soter when he chose Egypt as his portion of the dismembered +empire of the great Macedonian. Ptolemy had been with his master +in the East, and was with him in Babylonia when he died. He had +therefore come personally in contact with Babylonian +civilization, and we cannot doubt that this had a most important +influence upon his life, and through him upon the new +civilization of the West. In point of culture, Alexandria must be +regarded as the successor of Babylon, scarcely less directly than +of Greece. Following the Babylonian model, Ptolemy erected a +great museum and began collecting a library. Before his death it +was said that he had collected no fewer than two hundred thousand +manuscripts. He had gathered also a company of great teachers and +founded a school of science which, as has just been said, made +Alexandria the culture-centre of the world. + +Athens in the day of her prime had known nothing quite like this. +Such private citizens as Aristotle are known to have had +libraries, but there were no great public collections of books in +Athens, or in any other part of the Greek domain, until Ptolemy +founded his famous library. As is well known, such libraries had +existed in Babylonia for thousands of years. The character which +the Ptolemaic epoch took on was no doubt due to Babylonian +influence, but quite as much to the personal experience of +Ptolemy himself as an explorer in the Far East. The marvellous +conquering journey of Alexander had enormously widened the +horizon of the Greek geographer, and stimulated the imagination +of all ranks of the people, It was but natural, then, that +geography and its parent science astronomy should occupy the +attention of the best minds in this succeeding epoch. In point of +fact, such a company of star-gazers and earth-measurers came upon +the scene in this third century B.C. as had never before existed +anywhere in the world. The whole trend of the time was towards +mechanics. It was as if the greatest thinkers had squarely faced +about from the attitude of the mystical philosophers of the +preceding century, and had set themselves the task of solving all +the mechanical riddles of the universe, They no longer troubled +themselves about problems of "being" and "becoming"; they gave +but little heed to metaphysical subtleties; they demanded that +their thoughts should be gauged by objective realities. Hence +there arose a succession of great geometers, and their +conceptions were applied to the construction of new mechanical +contrivances on the one hand, and to the elaboration of theories +of sidereal mechanics on the other. + +The wonderful company of men who performed the feats that are +about to be recorded did not all find their home in Alexandria, +to be sure; but they all came more or less under the Alexandrian +influence. We shall see that there are two other important +centres; one out in Sicily, almost at the confines of the Greek +territory in the west; the other in Asia Minor, notably on the +island of Samos--the island which, it will be recalled, was at an +earlier day the birthplace of Pythagoras. But whereas in the +previous century colonists from the confines of the civilized +world came to Athens, now all eyes turned towards Alexandria, and +so improved were the facilities for communication that no doubt +the discoveries of one coterie of workers were known to all the +others much more quickly than had ever been possible before. We +learn, for example, that the studies of Aristarchus of Samos were +definitely known to Archimedes of Syracuse, out in Sicily. +Indeed, as we shall see, it is through a chance reference +preserved in one of the writings of Archimedes that one of the +most important speculations of Aristarchus is made known to us. +This illustrates sufficiently the intercommunication through +which the thought of the Alexandrian epoch was brought into a +single channel. We no longer, as in the day of the earlier +schools of Greek philosophy, have isolated groups of thinkers. +The scientific drama is now played out upon a single stage; and +if we pass, as we shall in the present chapter, from Alexandria +to Syracuse and from Syracuse to Samos, the shift of scenes does +no violence to the dramatic unities. + +Notwithstanding the number of great workers who were not properly +Alexandrians, none the less the epoch is with propriety termed +Alexandrian. Not merely in the third century B.C., but throughout +the lapse of at least four succeeding centuries, the city of +Alexander and the Ptolemies continued to hold its place as the +undisputed culture-centre of the world. During that period Rome +rose to its pinnacle of glory and began to decline, without ever +challenging the intellectual supremacy of the Egyptian city. We +shall see, in a later chapter, that the Alexandrian influences +were passed on to the Mohammedan conquerors, and every one is +aware that when Alexandria was finally overthrown its place was +taken by another Greek city, Byzantium or Constantinople. But +that transfer did not occur until Alexandria had enjoyed a longer +period of supremacy as an intellectual centre than had perhaps +ever before been granted to any city, with the possible +exception of Babylon. + + +EUCLID (ABOUT 300 B.C.) + +Our present concern is with that first wonderful development of +scientific activity which began under the first Ptolemy, and +which presents, in the course of the first century of Alexandrian +influence, the most remarkable coterie of scientific workers and +thinkers that antiquity produced. The earliest group of these new +leaders in science had at its head a man whose name has been a +household word ever since. This was Euclid, the father of +systematic geometry. Tradition has preserved to us but little of +the personality of this remarkable teacher; but, on the other +hand, his most important work has come down to us in its +entirety. The Elements of Geometry, with which the name of Euclid +is associated in the mind of every school-boy, presented the +chief propositions of its subject in so simple and logical a form +that the work remained a textbook everywhere for more than two +thousand years. Indeed it is only now beginning to be superseded. +It is not twenty years since English mathematicians could deplore +the fact that, despite certain rather obvious defects of the work +of Euclid, no better textbook than this was available. Euclid's +work, of course, gives expression to much knowledge that did not +originate with him. We have already seen that several important +propositions of geometry had been developed by Thales, and one by +Pythagoras, and that the rudiments of the subject were at least +as old as Egyptian civilization. Precisely how much Euclid added +through his own investigations cannot be ascertained. It seems +probable that he was a diffuser of knowledge rather than an +originator, but as a great teacher his fame is secure. He is +credited with an epigram which in itself might insure him +perpetuity of fame: "There is no royal road to geometry," was his +answer to Ptolemy when that ruler had questioned whether the +Elements might not be simplified. Doubtless this, like most +similar good sayings, is apocryphal; but whoever invented it has +made the world his debtor. + + +HEROPHILUS AND ERASISTRATUS + +The catholicity of Ptolemy's tastes led him, naturally enough, to +cultivate the biological no less than the physical sciences. In +particular his influence permitted an epochal advance in the +field of medicine. Two anatomists became famous through the +investigations they were permitted to make under the patronage of +the enlightened ruler. These earliest of really scientific +investigators of the mechanism of the human body were named +Herophilus and Erasistratus. These two anatomists gained their +knowledge by the dissection of human bodies (theirs are the first +records that we have of such practices), and King Ptolemy himself +is said to have been present at some of these dissections. They +were the first to discover that the nerve- trunks have their +origin in the brain and spinal cord, and they are credited also +with the discovery that these nerve-trunks are of two different +kinds--one to convey motor, and the other sensory impulses. They +discovered, described, and named the coverings of the brain. The +name of Herophilus is still applied by anatomists, in honor of +the discoverer, to one of the sinuses or large canals that convey +the venous blood from the head. Herophilus also noticed and +described four cavities or ventricles in the brain, and reached +the conclusion that one of these ventricles was the seat of the +soul--a belief shared until comparatively recent times by many +physiologists. He made also a careful and fairly accurate study +of the anatomy of the eye, a greatly improved the old operation +for cataract. + +With the increased knowledge of anatomy came also corresponding +advances in surgery, and many experimental operations are said to +have been performed upon condemned criminals who were handed over +to the surgeons by the Ptolemies. While many modern writers have +attempted to discredit these assertions, it is not improbable +that such operations were performed. In an age when human life +was held so cheap, and among a people accustomed to torturing +condemned prisoners for comparatively slight offences, it is not +unlikely that the surgeons were allowed to inflict perhaps less +painful tortures in the cause of science. Furthermore, we know +that condemned criminals were sometimes handed over to the +medical profession to be "operated upon and killed in whatever +way they thought best" even as late as the sixteenth century. +Tertullian[1] probably exaggerates, however, when he puts the +number of such victims in Alexandria at six hundred. + +Had Herophilus and Erasistratus been as happy in their deductions +as to the functions of the organs as they were in their knowledge +of anatomy, the science of medicine would have been placed upon a +very high plane even in their time. Unfortunately, however, they +not only drew erroneous inferences as to the functions of the +organs, but also disagreed radically as to what functions certain +organs performed, and how diseases should be treated, even when +agreeing perfectly on the subject of anatomy itself. Their +contribution to the knowledge of the scientific treatment of +diseases holds no such place, therefore, as their anatomical +investigations. + +Half a century after the time of Herophilus there appeared a +Greek physician, Heraclides, whose reputation in the use of drugs +far surpasses that of the anatomists of the Alexandrian school. +His reputation has been handed down through the centuries as that +of a physician, rather than a surgeon, although in his own time +he was considered one of the great surgeons of the period. +Heraclides belonged to the "Empiric" school, which rejected +anatomy as useless, depending entirely on the use of drugs. He is +thought to have been the first physician to point out the value +of opium in certain painful diseases. His prescription of this +drug for certain cases of "sleeplessness, spasm, cholera, and +colic," shows that his use of it was not unlike that of the +modern physician in certain cases; and his treatment of fevers, +by keeping the patient's head cool and facilitating the +secretions of the body, is still recognized as "good practice." +He advocated a free use of liquids in quenching the fever +patient's thirst--a recognized therapeutic measure to-day, but +one that was widely condemned a century ago. + + +ARCHIMEDES OF SYRACUSE AND THE FOUNDATION OF MECHANICS + +We do not know just when Euclid died, but as he was at the height +of his fame in the time of Ptolemy I., whose reign ended in the +year 285 B.C., it is hardly probable that he was still living +when a young man named Archimedes came to Alexandria to study. +Archimedes was born in the Greek colony of Syracuse, on the +island of Sicily, in the year 287 B.C. When he visited Alexandria +he probably found Apollonius of Perga, the pupil of Euclid, at +the head of the mathematical school there. Just how long +Archimedes remained at Alexandria is not known. When he had +satisfied his curiosity or completed his studies, he returned to +Syracuse and spent his life there, chiefly under the patronage of +King Hiero, who seems fully to have appreciated his abilities. + +Archimedes was primarily a mathematician. Left to his own +devices, he would probably have devoted his entire time to the +study of geometrical problems. But King Hiero had discovered that +his protege had wonderful mechanical ingenuity, and he made good +use of this discovery. Under stress of the king's urgings, the +philosopher was led to invent a great variety of mechanical +contrivances, some of them most curious ones. Antiquity credited +him with the invention of more than forty machines, and it is +these, rather than his purely mathematical discoveries, that gave +his name popular vogue both among his contemporaries and with +posterity. Every one has heard of the screw of Archimedes, +through which the paradoxical effect was produced of making water +seem to flow up hill. The best idea of this curious mechanism is +obtained if one will take in hand an ordinary corkscrew, and +imagine this instrument to be changed into a hollow tube, +retaining precisely the same shape but increased to some feet in +length and to a proportionate diameter. If one will hold the +corkscrew in a slanting direction and turn it slowly to the +right, supposing that the point dips up a portion of water each +time it revolves, one can in imagination follow the flow of that +portion of water from spiral to spiral, the water always running +downward, of course, yet paradoxically being lifted higher and +higher towards the base of the corkscrew, until finally it pours +out (in the actual Archimedes' tube) at the top. There is another +form of the screw in which a revolving spiral blade operates +within a cylinder, but the principle is precisely the same. With +either form water may be lifted, by the mere turning of the +screw, to any desired height. The ingenious mechanism excited the +wonder of the contemporaries of Archimedes, as well it might. +More efficient devices have superseded it in modern times, but it +still excites the admiration of all who examine it, and its +effects seem as paradoxical as ever. + +Some other of the mechanisms of Archimedes have been made known +to successive generations of readers through the pages of +Polybius and Plutarch. These are the devices through which +Archimedes aided King Hiero to ward off the attacks of the Roman +general Marcellus, who in the course of the second Punic war laid +siege to Syracuse. + +Plutarch, in his life of Marcellus, describes the Roman's attack +and Archimedes' defence in much detail. Incidentally he tells us +also how Archimedes came to make the devices that rendered the +siege so famous: + +"Marcellus himself, with threescore galleys of five rowers at +every bank, well armed and full of all sorts of artillery and +fireworks, did assault by sea, and rowed hard to the wall, having +made a great engine and device of battery, upon eight galleys +chained together, to batter the wall: trusting in the great +multitude of his engines of battery, and to all such other +necessary provision as he had for wars, as also in his own +reputation. But Archimedes made light account of all his devices, +as indeed they were nothing comparable to the engines himself had +invented. This inventive art to frame instruments and engines +(which are called mechanical, or organical, so highly commended +and esteemed of all sorts of people) was first set forth by +Architas, and by Eudoxus: partly to beautify a little the science +of geometry by this fineness, and partly to prove and confirm by +material examples and sensible instruments, certain geometrical +conclusions, where of a man cannot find out the conceivable +demonstrations by enforced reasons and proofs. As that conclusion +which instructeth one to search out two lines mean proportional, +which cannot be proved by reason demonstrative, and yet +notwithstanding is a principle and an accepted ground for many +things which are contained in the art of portraiture. Both of +them have fashioned it to the workmanship of certain instruments, +called mesolabes or mesographs, which serve to find these mean +lines proportional, by drawing certain curve lines, and +overthwart and oblique sections. But after that Plato was +offended with them, and maintained against them, that they did +utterly corrupt and disgrace, the worthiness and excellence of +geometry, making it to descend from things not comprehensible and +without body, unto things sensible and material, and to bring it +to a palpable substance, where the vile and base handiwork of man +is to be employed: since that time, I say, handicraft, or the art +of engines, came to be separated from geometry, and being long +time despised by the philosophers, it came to be one of the +warlike arts. + +"But Archimedes having told King Hiero, his kinsman and friend, +that it was possible to remove as great a weight as he would, +with as little strength as he listed to put to it: and boasting +himself thus (as they report of him) and trusting to the force of +his reasons, wherewith he proved this conclusion, that if there +were another globe of earth, he was able to remove this of ours, +and pass it over to the other: King Hiero wondering to hear him, +required him to put his device in execution, and to make him see +by experience, some great or heavy weight removed, by little +force. So Archimedes caught hold with a book of one of the +greatest carects, or hulks of the king (that to draw it to the +shore out of the water required a marvellous number of people to +go about it, and was hardly to be done so) and put a great number +of men more into her, than her ordinary burden: and he himself +sitting alone at his ease far off, without any straining at all, +drawing the end of an engine with many wheels and pulleys, fair +and softly with his hand, made it come as gently and smoothly to +him, as it had floated in the sea. The king wondering to see the +sight, and knowing by proof the greatness of his art; be prayed +him to make him some engines, both to assault and defend, in all +manner of sieges and assaults. So Archimedes made him many +engines, but King Hiero never occupied any of them, because he +reigned the most part of his time in peace without any wars. But +this provision and munition of engines, served the Syracusan's +turn marvellously at that time: and not only the provision of the +engines ready made, but also the engineer and work-master +himself, that had invented them. + +"Now the Syracusans, seeing themselves assaulted by the Romans, +both by sea and by land, were marvellously perplexed, and could +not tell what to say, they were so afraid: imagining it was +impossible for them to withstand so great an army. But when +Archimedes fell to handling his engines, and to set them at +liberty, there flew in the air infinite kinds of shot, and +marvellous great stones, with an incredible noise and force on +the sudden, upon the footmen that came to assault the city by +land, bearing down, and tearing in pieces all those which came +against them, or in what place soever they lighted, no earthly +body being able to resist the violence of so heavy a weight: so +that all their ranks were marvellously disordered. And as for the +galleys that gave assault by sea, some were sunk with long pieces +of timber like unto the yards of ships, whereto they fasten their +sails, which were suddenly blown over the walls with force of +their engines into their galleys, and so sunk them by their over +great weight." + + +Polybius describes what was perhaps the most important of these +contrivances, which was, he tells us, "a band of iron, hanging by +a chain from the beak of a machine, which was used in the +following manner. The person who, like a pilot, guided the beak, +having let fall the hand, and catched hold of the prow of any +vessel, drew down the opposite end of the machine that was on the +inside of the walls. And when the vessel was thus raised erect +upon its stem, the machine itself was held immovable; but, the +chain being suddenly loosened from the beak by the means of +pulleys, some of the vessels were thrown upon their sides, others +turned with the bottom upwards; and the greatest part, as the +prows were plunged from a considerable height into the sea, were +filled with water, and all that were on board thrown into tumult +and disorder. + +"Marcellus was in no small degree embarrassed," Polybius +continues, "when he found himself encountered in every attempt by +such resistance. He perceived that all his efforts were defeated +with loss; and were even derided by the enemy. But, amidst all +the anxiety that he suffered, he could not help jesting upon the +inventions of Archimedes. This man, said he, employs our ships as +buckets to draw water: and boxing about our sackbuts, as if they +were unworthy to be associated with him, drives them from his +company with disgrace. Such was the success of the siege on the +side of the sea." + +Subsequently, however, Marcellus took the city by strategy, and +Archimedes was killed, contrary, it is said, to the express +orders of Marcellus. "Syracuse being taken," says Plutarch, +"nothing grieved Marcellus more than the loss of Archimedes. Who, +being in his study when the city was taken, busily seeking out by +himself the demonstration of some geometrical proposition which +he had drawn in figure, and so earnestly occupied therein, as he +neither saw nor heard any noise of enemies that ran up and down +the city, and much less knew it was taken: he wondered when he +saw a soldier by him, that bade him go with him to Marcellus. +Notwithstanding, he spake to the soldier, and bade him tarry +until he had done his conclusion, and brought it to +demonstration: but the soldier being angry with his answer, drew +out his sword and killed him. Others say, that the Roman soldier +when he came, offered the sword's point to him, to kill him: and +that Archimedes when he saw him, prayed him to hold his hand a +little, that he might not leave the matter he looked for +imperfect, without demonstration. But the soldier making no +reckoning of his speculation, killed him presently. It is +reported a third way also, saying that certain soldiers met him +in the streets going to Marcellus, carrying certain mathematical +instruments in a little pretty coffer, as dials for the sun, +spheres, and angles, wherewith they measure the greatness of the +body of the sun by view: and they supposing he had carried some +gold or silver, or other precious jewels in that little coffer, +slew him for it. But it is most certain that Marcellus was +marvellously sorry for his death, and ever after hated the +villain that slew him, as a cursed and execrable person: and how +he had made also marvellous much afterwards of Archimedes' +kinsmen for his sake." + +We are further indebted to Plutarch for a summary of the +character and influence of Archimedes, and for an interesting +suggestion as to the estimate which the great philosopher put +upon the relative importance of his own discoveries. +"Notwithstanding Archimedes had such a great mind, and was so +profoundly learned, having hidden in him the only treasure and +secrets of geometrical inventions: as be would never set forth +any book how to make all these warlike engines, which won him at +that time the fame and glory, not of man's knowledge, but rather +of divine wisdom. But he esteeming all kind of handicraft and +invention to make engines, and generally all manner of sciences +bringing common commodity by the use of them, to be but vile, +beggarly, and mercenary dross: employed his wit and study only to +write things, the beauty and subtlety whereof were not mingled +anything at all with necessity. For all that he hath written, are +geometrical propositions, which are without comparison of any +other writings whatsoever: because the subject where of they +treat, doth appear by demonstration, the maker gives them the +grace and the greatness, and the demonstration proving it so +exquisitely, with wonderful reason and facility, as it is not +repugnable. For in all geometry are not to be found more profound +and difficult matters written, in more plain and simple terms, +and by more easy principles, than those which he hath invented. +Now some do impute this, to the sharpness of his wit and +understanding, which was a natural gift in him: others do refer +it to the extreme pains he took, which made these things come so +easily from him, that they seemed as if they had been no trouble +to him at all. For no man living of himself can devise the +demonstration of his propositions, what pains soever he take to +seek it: and yet straight so soon as he cometh to declare and +open it, every man then imagineth with himself he could have +found it out well enough, he can then so plainly make +demonstration of the thing he meaneth to show. And therefore that +methinks is likely to be true, which they write of him: that he +was so ravished and drunk with the sweet enticements of this +siren, which as it were lay continually with him, as he forgot +his meat and drink, and was careless otherwise of himself, that +oftentimes his servants got him against his will to the baths to +wash and anoint him: and yet being there, he would ever be +drawing out of the geometrical figures, even in the very imbers +of the chimney. And while they were anointing of him with oils +and sweet savours, with his finger he did draw lines upon his +naked body: so far was he taken from himself, and brought into an +ecstasy or trance, with the delight he had in the study of +geometry, and truly ravished with the love of the Muses. But +amongst many notable things he devised, it appeareth, that he +most esteemed the demonstration of the proportion between the +cylinder (to wit, the round column) and the sphere or globe +contained in the same: for he prayed his kinsmen and friends, +that after his death they would put a cylinder upon his tomb, +containing a massy sphere, with an inscription of the proportion, +whereof the continent exceedeth the thing contained."[2] + +It should be observed that neither Polybius nor Plutarch mentions +the use of burning-glasses in connection with the siege of +Syracuse, nor indeed are these referred to by any other ancient +writer of authority. Nevertheless, a story gained credence down +to a late day to the effect that Archimedes had set fire to the +fleet of the enemy with the aid of concave mirrors. An experiment +was made by Sir Isaac Newton to show the possibility of a +phenomenon so well in accord with the genius of Archimedes, but +the silence of all the early authorities makes it more than +doubtful whether any such expedient was really adopted. + +It will be observed that the chief principle involved in all +these mechanisms was a capacity to transmit great power through +levers and pulleys, and this brings us to the most important +field of the Syracusan philosopher's activity. It was as a +student of the lever and the pulley that Archimedes was led to +some of his greatest mechanical discoveries. He is even credited +with being the discoverer of the compound pulley. More likely he +was its developer only, since the principle of the pulley was +known to the old Babylonians, as their sculptures testify. But +there is no reason to doubt the general outlines of the story +that Archimedes astounded King Hiero by proving that, with the +aid of multiple pulleys, the strength of one man could suffice to +drag the largest ship from its moorings. + +The property of the lever, from its fundamental principle, was +studied by him, beginning with the self- evident fact that "equal +bodies at the ends of the equal arms of a rod, supported on its +middle point, will balance each other"; or, what amounts to the +same thing stated in another way, a regular cylinder of uniform +matter will balance at its middle point. From this starting-point +he elaborated the subject on such clear and satisfactory +principles that they stand to-day practically unchanged and with +few additions. From all his studies and experiments he finally +formulated the principle that "bodies will be in equilibrio when +their distance from the fulcrum or point of support is inversely +as their weight." He is credited with having summed up his +estimate of the capabilities of the lever with the well-known +expression, "Give me a fulcrum on which to rest or a place on +which to stand, and I will move the earth." + +But perhaps the feat of all others that most appealed to the +imagination of his contemporaries, and possibly also the one that +had the greatest bearing upon the position of Archimedes as a +scientific discoverer, was the one made familiar through the tale +of the crown of Hiero. This crown, so the story goes, was +supposed to be made of solid gold, but King Hiero for some reason +suspected the honesty of the jeweller, and desired to know if +Archimedes could devise a way of testing the question without +injuring the crown. Greek imagination seldom spoiled a story in +the telling, and in this case the tale was allowed to take on the +most picturesque of phases. The philosopher, we are assured, +pondered the problem for a long time without succeeding, but one +day as he stepped into a bath, his attention was attracted by the +overflow of water. A new train of ideas was started in his +ever-receptive brain. Wild with enthusiasm he sprang from the +bath, and, forgetting his robe, dashed along the streets of +Syracuse, shouting: "Eureka! Eureka!" (I have found it!) The +thought that had come into his mind was this: That any heavy +substance must have a bulk proportionate to its weight; that gold +and silver differ in weight, bulk for bulk, and that the way to +test the bulk of such an irregular object as a crown was to +immerse it in water. The experiment was made. A lump of pure gold +of the weight of the crown was immersed in a certain receptacle +filled with water, and the overflow noted. Then a lump of pure +silver of the same weight was similarly immersed; lastly the +crown itself was immersed, and of course--for the story must not +lack its dramatic sequel--was found bulkier than its weight of +pure gold. Thus the genius that could balk warriors and armies +could also foil the wiles of the silversmith. + +Whatever the truth of this picturesque narrative, the fact +remains that some, such experiments as these must have paved the +way for perhaps the greatest of all the studies of +Archimedes--those that relate to the buoyancy of water. Leaving +the field of fable, we must now examine these with some +precision. Fortunately, the writings of Archimedes himself are +still extant, in which the results of his remarkable experiments +are related, so we may present the results in the words of the +discoverer. + +Here they are: "First: The surface of every coherent liquid in a +state of rest is spherical, and the centre of the sphere +coincides with the centre of the earth. Second: A solid body +which, bulk for bulk, is of the same weight as a liquid, if +immersed in the liquid will sink so that the surface of the body +is even with the surface of the liquid, but will not sink deeper. +Third: Any solid body which is lighter, bulk for bulk, than a +liquid, if placed in the liquid will sink so deep as to displace +the mass of liquid equal in weight to another body. Fourth: If a +body which is lighter than a liquid is forcibly immersed in the +liquid, it will be pressed upward with a force corresponding to +the weight of a like volume of water, less the weight of the body +itself. Fifth: Solid bodies which, bulk for bulk, are heavier +than a liquid, when immersed in the liquid sink to the bottom, +but become in the liquid as much lighter as the weight of the +displaced water itself differs from the weight of the solid." +These propositions are not difficult to demonstrate, once they +are conceived, but their discovery, combined with the discovery +of the laws of statics already referred to, may justly be +considered as proving Archimedes the most inventive experimenter +of antiquity. + +Curiously enough, the discovery which Archimedes himself is said +to have considered the most important of all his innovations is +one that seems much less striking. It is the answer to the +question, What is the relation in bulk between a sphere and its +circumscribing cylinder? Archimedes finds that the ratio is +simply two to three. We are not informed as to how he reached his +conclusion, but an obvious method would be to immerse a ball in a +cylindrical cup. The experiment is one which any one can make for +himself, with approximate accuracy, with the aid of a tumbler and +a solid rubber ball or a billiard-ball of just the right size. +Another geometrical problem which Archimedes solved was the +problem as to the size of a triangle which has equal area with a +circle; the answer being, a triangle having for its base the +circumference of the circle and for its altitude the radius. +Archimedes solved also the problem of the relation of the +diameter of the circle to its circumference; his answer being a +close approximation to the familiar 3.1416, which every tyro in +geometry will recall as the equivalent of pi. + +Numerous other of the studies of Archimedes having reference to +conic sections, properties of curves and spirals, and the like, +are too technical to be detailed here. The extent of his +mathematical knowledge, however, is suggested by the fact that he +computed in great detail the number of grains of sand that would +be required to cover the sphere of the sun's orbit, making +certain hypothetical assumptions as to the size of the earth and +the distance of the sun for the purposes of argument. +Mathematicians find his computation peculiarly interesting +because it evidences a crude conception of the idea of +logarithms. From our present stand-point, the paper in which this +calculation is contained has considerable interest because of its +assumptions as to celestial mechanics. Thus Archimedes starts out +with the preliminary assumption that the circumference of the +earth is less than three million stadia. It must be understood +that this assumption is purely for the sake of argument. +Archimedes expressly states that he takes this number because it +is "ten times as large as the earth has been supposed to be by +certain investigators." Here, perhaps, the reference is to +Eratosthenes, whose measurement of the earth we shall have +occasion to revert to in a moment. Continuing, Archimedes asserts +that the sun is larger than the earth, and the earth larger than +the moon. In this assumption, he says, he is following the +opinion of the majority of astronomers. In the third place, +Archimedes assumes that the diameter of the sun is not more than +thirty times greater than that of the moon. Here he is probably +basing his argument upon another set of measurements of +Aristarchus, to which, also, we shall presently refer more at +length. In reality, his assumption is very far from the truth, +since the actual diameter of the sun, as we now know, is +something like four hundred times that of the moon. Fourth, the +circumference of the sun is greater than one side of the +thousand- faced figure inscribed in its orbit. The measurement, +it is expressly stated, is based on the measurements of +Aristarchus, who makes the diameter of the sun 1/170 of its +orbit. Archimedes adds, however, that he himself has measured the +angle and that it appears to him to be less than 1/164, and +greater than 1/200 part of the orbit. That is to say, reduced to +modern terminology, he places the limit of the sun's apparent +size between thirty-three minutes and twenty-seven minutes of +arc. As the real diameter is thirty-two minutes, this calculation +is surprisingly exact, considering the implements then at +command. But the honor of first making it must be given to +Aristarchus and not to Archimedes. + +We need not follow Archimedes to the limits of his +incomprehensible numbers of sand-grains. The calculation is +chiefly remarkable because it was made before the introduction of +the so-called Arabic numerals had simplified mathematical +calculations. It will be recalled that the Greeks used letters +for numerals, and, having no cipher, they soon found themselves +in difficulties when large numbers were involved. The Roman +system of numerals simplified the matter somewhat, but the +beautiful simplicity of the decimal system did not come into +vogue until the Middle Ages, as we shall see. Notwithstanding the +difficulties, however, Archimedes followed out his calculations +to the piling up of bewildering numbers, which the modern +mathematician finds to be the consistent outcome of the problem +he had set himself. + +But it remains to notice the most interesting feature of this +document in which the calculation of the sand- grains is +contained. "It was known to me," says Archimedes, "that most +astronomers understand by the expression 'world' (universe) a +ball of which the centre is the middle point of the earth, and of +which the radius is a straight line between the centre of the +earth and the sun." Archimedes himself appears to accept this +opinion of the majority,--it at least serves as well as the +contrary hypothesis for the purpose of his calculation,--but he +goes on to say: "Aristarchus of Samos, in his writing against the +astronomers, seeks to establish the fact that the world is really +very different from this. He holds the opinion that the fixed +stars and the sun are immovable and that the earth revolves in a +circular line about the sun, the sun being at the centre of this +circle." This remarkable bit of testimony establishes beyond +question the position of Aristarchus of Samos as the Copernicus +of antiquity. We must make further inquiry as to the teachings of +the man who had gained such a remarkable insight into the true +system of the heavens. + + +ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY + +It appears that Aristarchus was a contemporary of Archimedes, but +the exact dates of his life are not known. He was actively +engaged in making astronomical observations in Samos somewhat +before the middle of the third century B.C.; in other words, just +at the time when the activities of the Alexandrian school were at +their height. Hipparchus, at a later day, was enabled to compare +his own observations with those made by Aristarchus, and, as we +have just seen, his work was well known to so distant a +contemporary as Archimedes. Yet the facts of his life are almost +a blank for us, and of his writings only a single one has been +preserved. That one, however, is a most important and interesting +paper on the measurements of the sun and the moon. Unfortunately, +this paper gives us no direct clew as to the opinions of +Aristarchus concerning the relative positions of the earth and +sun. But the testimony of Archimedes as to this is unequivocal, +and this testimony is supported by other rumors in themselves +less authoritative. + +In contemplating this astronomer of Samos, then, we are in the +presence of a man who had solved in its essentials the problem of +the mechanism of the solar system. It appears from the words of +Archimedes that Aristarchus; had propounded his theory in +explicit writings. Unquestionably, then, he held to it as a +positive doctrine, not as a mere vague guess. We shall show, in a +moment, on what grounds he based his opinion. Had his teaching +found vogue, the story of science would be very different from +what it is. We should then have no tale to tell of a Copernicus +coming upon the scene fully seventeen hundred years later with +the revolutionary doctrine that our world is not the centre of +the universe. We should not have to tell of the persecution of a +Bruno or of a Galileo for teaching this doctrine in the +seventeenth century of an era which did not begin till two +hundred years after the death of Aristarchus. But, as we know, +the teaching of the astronomer of Samos did not win its way. The +old conservative geocentric doctrine, seemingly so much more in +accordance with the every-day observations of mankind, supported +by the majority of astronomers with the Peripatetic philosophers +at their head, held its place. It found fresh supporters +presently among the later Alexandrians, and so fully eclipsed the +heliocentric view that we should scarcely know that view had even +found an advocate were it not for here and there such a chance +record as the phrases we have just quoted from Archimedes. Yet, +as we now see, the heliocentric doctrine, which we know to be +true, had been thought out and advocated as the correct theory of +celestial mechanics by at least one worker of the third century +B.C. Such an idea, we may be sure, did not spring into the mind +of its originator except as the culmination of a long series of +observations and inferences. The precise character of the +evolution we perhaps cannot trace, but its broader outlines are +open to our observation, and we may not leave so important a +topic without at least briefly noting them. + +Fully to understand the theory of Aristarchus, we must go back a +century or two and recall that as long ago as the time of that +other great native of Samos, Pythagoras, the conception had been +reached that the earth is in motion. We saw, in dealing with +Pythagoras, that we could not be sure as to precisely what he +himself taught, but there is no question that the idea of the +world's motion became from an early day a so-called Pythagorean +doctrine. While all the other philosophers, so far as we know, +still believed that the world was flat, the Pythagoreans out in +Italy taught that the world is a sphere and that the apparent +motions of the heavenly bodies are really due to the actual +motion of the earth itself. They did not, however, vault to the +conclusion that this true motion of the earth takes place in the +form of a circuit about the sun. Instead of that, they conceived +the central body of the universe to be a great fire, invisible +from the earth, because the inhabited side of the terrestrial +ball was turned away from it. The sun, it was held, is but a +great mirror, which reflects the light from the central fire. Sun +and earth alike revolve about this great fire, each in its own +orbit. Between the earth and the central fire there was, +curiously enough, supposed to be an invisible earthlike body +which was given the name of Anticthon, or counter-earth. This +body, itself revolving about the central fire, was supposed to +shut off the central light now and again from the sun or from the +moon, and thus to account for certain eclipses for which the +shadow of the earth did not seem responsible. It was, perhaps, +largely to account for such eclipses that the counter-earth was +invented. But it is supposed that there was another reason. The +Pythagoreans held that there is a peculiar sacredness in the +number ten. Just as the Babylonians of the early day and the +Hegelian philosophers of a more recent epoch saw a sacred +connection between the number seven and the number of planetary +bodies, so the Pythagoreans thought that the universe must be +arranged in accordance with the number ten. Their count of the +heavenly bodies, including the sphere of the fixed stars, seemed +to show nine, and the counter-earth supplied the missing body. + +The precise genesis and development of this idea cannot now be +followed, but that it was prevalent about the fifth century B.C. +as a Pythagorean doctrine cannot be questioned. Anaxagoras also +is said to have taken account of the hypothetical counter-earth +in his explanation of eclipses; though, as we have seen, he +probably did not accept that part of the doctrine which held the +earth to be a sphere. The names of Philolaus and Heraclides have +been linked with certain of these Pythagorean doctrines. Eudoxus, +too, who, like the others, lived in Asia Minor in the fourth +century B.C., was held to have made special studies of the +heavenly spheres and perhaps to have taught that the earth moves. +So, too, Nicetas must be named among those whom rumor credited +with having taught that the world is in motion. In a word, the +evidence, so far as we can garner it from the remaining +fragments, tends to show that all along, from the time of the +early Pythagoreans, there had been an undercurrent of opinion in +the philosophical world which questioned the fixity of the earth; +and it would seem that the school of thinkers who tended to +accept the revolutionary view centred in Asia Minor, not far from +the early home of the founder of the Pythagorean doctrines. It +was not strange, then, that the man who was finally to carry +these new opinions to their logical conclusion should hail from +Samos. + +But what was the support which observation could give to this +new, strange conception that the heavenly bodies do not in +reality move as they seem to move, but that their apparent motion +is due to the actual revolution of the earth? It is extremely +difficult for any one nowadays to put himself in a mental +position to answer this question. We are so accustomed to +conceive the solar system as we know it to be, that we are wont +to forget how very different it is from what it seems. Yet one +needs but to glance up at the sky, and then to glance about one +at the solid earth, to grant, on a moment's reflection, that the +geocentric idea is of all others the most natural; and that to +conceive the sun as the actual Centre of the solar system is an +idea which must look for support to some other evidence than that +which ordinary observation can give. Such was the view of most of +the ancient philosophers, and such continued to be the opinion of +the majority of mankind long after the time of Copernicus. We +must not forget that even so great an observing astronomer as +Tycho Brahe, so late as the seventeenth century, declined to +accept the heliocentric theory, though admitting that all the +planets except the earth revolve about the sun. We shall see that +before the Alexandrian school lost its influence a geocentric +scheme had been evolved which fully explained all the apparent +motions of the heavenly bodies. All this, then, makes us but +wonder the more that the genius of an Aristarchus could give +precedence to scientific induction as against the seemingly clear +evidence of the senses. + +What, then, was the line of scientific induction that led +Aristarchus to this wonderful goal? Fortunately, we are able to +answer that query, at least in part. Aristarchus gained his +evidence through some wonderful measurements. First, he measured +the disks of the sun and the moon. This, of course, could in +itself give him no clew to the distance of these bodies, and +therefore no clew as to their relative size; but in attempting to +obtain such a clew he hit upon a wonderful yet altogether simple +experiment. It occurred to him that when the moon is precisely +dichotomized-- that is to say, precisely at the half-the line of +vision from the earth to the moon must be precisely at right +angles with the line of light passing from the sun to the moon. +At this moment, then, the imaginary lines joining the sun, the +moon, and the earth, make a right angle triangle. But the +properties of the right-angle triangle had long been studied and +were well under stood. One acute angle of such a triangle +determines the figure of the triangle itself. We have already +seen that Thales, the very earliest of the Greek philosophers, +measured the distance of a ship at sea by the application of this +principle. Now Aristarchus sights the sun in place of Thales' +ship, and, sighting the moon at the same time, measures the angle +and establishes the shape of his right-angle triangle. This does +not tell him the distance of the sun, to be sure, for he does not +know the length of his base-line--that is to say, of the line +between the moon and the earth. But it does establish the +relation of that base-line to the other lines of the triangle; in +other words, it tells him the distance of the sun in terms of the +moon's distance. As Aristarchus strikes the angle, it shows that +the sun is eighteen times as distant as the moon. Now, by +comparing the apparent size of the sun with the apparent size of +the moon--which, as we have seen, Aristarchus has already +measured--he is able to tell us that, the sun is "more than 5832 +times, and less than 8000" times larger than the moon; though his +measurements, taken by themselves, give no clew to the actual +bulk of either body. These conclusions, be it understood, are +absolutely valid inferences--nay, demonstrations--from the +measurements involved, provided only that these measurements have +been correct. Unfortunately, the angle of the triangle we have +just seen measured is exceedingly difficult to determine with +accuracy, while at the same time, as a moment's reflection will +show, it is so large an angle that a very slight deviation from +the truth will greatly affect the distance at which its line +joins the other side of the triangle. Then again, it is virtually +impossible to tell the precise moment when the moon is at half, +as the line it gives is not so sharp that we can fix it with +absolute accuracy. There is, moreover, another element of error +due to the refraction of light by the earth's atmosphere. The +experiment was probably made when the sun was near the horizon, +at which time, as we now know, but as Aristarchus probably did +not suspect, the apparent displacement of the sun's position is +considerable; and this displacement, it will be observed, is in +the direction to lessen the angle in question. + +In point of fact, Aristarchus estimated the angle at eighty-seven +degrees. Had his instrument been more precise, and had he been +able to take account of all the elements of error, he would have +found it eighty-seven degrees and fifty-two minutes. The +difference of measurement seems slight; but it sufficed to make +the computations differ absurdly from the truth. The sun is +really not merely eighteen times but more than two hundred times +the distance of the moon, as Wendelein discovered on repeating +the experiment of Aristarchus about two thousand years later. Yet +this discrepancy does not in the least take away from the +validity of the method which Aristarchus employed. Moreover, his +conclusion, stated in general terms, was perfectly correct: the +sun is many times more distant than the moon and vastly larger +than that body. Granted, then, that the moon is, as Aristarchus +correctly believed, considerably less in size than the earth, the +sun must be enormously larger than the earth; and this is the +vital inference which, more than any other, must have seemed to +Aristarchus to confirm the suspicion that the sun and not the +earth is the centre of the planetary system. It seemed to him +inherently improbable that an enormously large body like the sun +should revolve about a small one such as the earth. And again, it +seemed inconceivable that a body so distant as the sun should +whirl through space so rapidly as to make the circuit of its +orbit in twenty- four hours. But, on the other hand, that a small +body like the earth should revolve about the gigantic sun seemed +inherently probable. This proposition granted, the rotation of +the earth on its axis follows as a necessary consequence in +explanation of the seeming motion of the stars. Here, then, was +the heliocentric doctrine reduced to a virtual demonstration by +Aristarchus of Samos, somewhere about the middle of the third +century B.C. + +It must be understood that in following out the, steps of +reasoning by which we suppose Aristarchus to have reached so +remarkable a conclusion, we have to some extent guessed at the +processes of thought- development; for no line of explication +written by the astronomer himself on this particular point has +come down to us. There does exist, however, as we have already +stated, a very remarkable treatise by Aristarchus on the Size and +Distance of the Sun and the Moon, which so clearly suggests the +methods of reasoning of the great astronomer, and so explicitly +cites the results of his measurements, that we cannot well pass +it by without quoting from it at some length. It is certainly one +of the most remarkable scientific documents of antiquity. As +already noted, the heliocentric doctrine is not expressly stated +here. It seems to be tacitly implied throughout, but it is not a +necessary consequence of any of the propositions expressly +stated. These propositions have to do with certain observations +and measurements and what Aristarchus believes to be inevitable +deductions from them, and he perhaps did not wish to have these +deductions challenged through associating them with a theory +which his contemporaries did not accept. In a word, the paper of +Aristarchus is a rigidly scientific document unvitiated by +association with any theorizings that are not directly germane to +its central theme. The treatise opens with certain hypotheses as +follows: + +"First. The moon receives its light from the sun. + +"Second. The earth may be considered as a point and as the centre +of the orbit of the moon. + +"Third. When the moon appears to us dichotomized it offers to our +view a great circle [or actual meridian] of its circumference +which divides the illuminated part from the dark part. + +"Fourth. When the moon appears dichotomized its distance from the +sun is less than a quarter of the circumference [of its orbit] by +a thirtieth part of that quarter." + +That is to say, in modern terminology, the moon at this time +lacks three degrees (one thirtieth of ninety degrees) of being at +right angles with the line of the sun as viewed from the earth; +or, stated otherwise, the angular distance of the moon from the +sun as viewed from the earth is at this time eighty-seven +degrees--this being, as we have already observed, the fundamental +measurement upon which so much depends. We may fairly suppose +that some previous paper of Aristarchus's has detailed the +measurement which here is taken for granted, yet which of course +could depend solely on observation. + +"Fifth. The diameter of the shadow [cast by the earth at the +point where the moon's orbit cuts that shadow when the moon is +eclipsed] is double the diameter of the moon." + +Here again a knowledge of previously established measurements is +taken for granted; but, indeed, this is the case throughout the +treatise. + +"Sixth. The arc subtended in the sky by the moon is a fifteenth +part of a sign" of the zodiac; that is to say, since there are +twenty-four, signs in the zodiac, one-fifteenth of one +twenty-fourth, or in modern terminology, one degree of arc. This +is Aristarchus's measurement of the moon to which we have already +referred when speaking of the measurements of Archimedes. + +"If we admit these six hypotheses," Aristarchus continues, "it +follows that the sun is more than eighteen times more distant +from the earth than is the moon, and that it is less than twenty +times more distant, and that the diameter of the sun bears a +corresponding relation to the diameter of the moon; which is +proved by the position of the moon when dichotomized. But the +ratio of the diameter of the sun to that of the earth is greater +than nineteen to three and less than forty-three to six. This is +demonstrated by the relation of the distances, by the position +[of the moon] in relation to the earth's shadow, and by the fact +that the arc subtended by the moon is a fifteenth part of a +sign." + +Aristarchus follows with nineteen propositions intended to +elucidate his hypotheses and to demonstrate his various +contentions. These show a singularly clear grasp of geometrical +problems and an altogether correct conception of the general +relations as to size and position of the earth, the moon, and the +sun. His reasoning has to do largely with the shadow cast by the +earth and by the moon, and it presupposes a considerable +knowledge of the phenomena of eclipses. His first proposition is +that "two equal spheres may always be circumscribed in a +cylinder; two unequal spheres in a cone of which the apex is +found on the side of the smaller sphere; and a straight line +joining the centres of these spheres is perpendicular to each of +the two circles made by the contact of the surface of the +cylinder or of the cone with the spheres." + +It will be observed that Aristarchus has in mind here the moon, +the earth, and the sun as spheres to be circumscribed within a +cone, which cone is made tangible and measurable by the shadows +cast by the non-luminous bodies; since, continuing, he clearly +states in proposition nine, that "when the sun is totally +eclipsed, an observer on the earth's surface is at an apex of a +cone comprising the moon and the sun." Various propositions deal +with other relations of the shadows which need not detain us +since they are not fundamentally important, and we may pass to +the final conclusions of Aristarchus, as reached in his +propositions ten to nineteen. + +Now, since (proposition ten) "the diameter of the sun is more +than eighteen times and less than twenty times greater than that +of the moon," it follows (proposition eleven) "that the bulk of +the sun is to that of the moon in ratio, greater than 5832 to 1, +and less than 8000 to 1." + +"Proposition sixteen. The diameter of the sun is to the diameter +of the earth in greater proportion than nineteen to three, and +less than forty-three to six. + +"Proposition seventeen. The bulk of the sun is to that of the +earth in greater proportion than 6859 to 27, and less than 79,507 +to 216. + +"Proposition eighteen. The diameter of the earth is to the +diameter of the moon in greater proportion than 108 to 43 and +less than 60 to 19. + +"Proposition nineteen. The bulk of the earth is to that of the +moon in greater proportion than 1,259,712 to 79,507 and less than +20,000 to 6859." + +Such then are the more important conclusions of this very +remarkable paper--a paper which seems to have interest to the +successors of Aristarchus generation after generation, since this +alone of all the writings of the great astronomer has been +preserved. How widely the exact results of the measurements of +Aristarchus, differ from the truth, we have pointed out as we +progressed. But let it be repeated that this detracts little from +the credit of the astronomer who had such clear and correct +conceptions of the relations of the heavenly bodies and who +invented such correct methods of measurement. Let it be +particularly observed, however, that all the conclusions of +Aristarchus are stated in relative terms. He nowhere attempts to +estimate the precise size of the earth, of the moon, or of the +sun, or the actual distance of one of these bodies from another. +The obvious reason for this is that no data were at hand from +which to make such precise measurements. Had Aristarchus known +the size of any one of the bodies in question, he might readily, +of course, have determined the size of the others by the mere +application of his relative scale; but he had no means of +determining the size of the earth, and to this extent his system +of measurements remained imperfect. Where Aristarchus halted, +however, another worker of the same period took the task in hand +and by an altogether wonderful measurement determined the size of +the earth, and thus brought the scientific theories of cosmology +to their climax. This worthy supplementor of the work of +Aristarchus was Eratosthenes of Alexandria. + + +ERATOSTHENES, "THE SURVEYOR OF THE WORLD" + +An altogether remarkable man was this native of Cyrene, who came +to Alexandria from Athens to be the chief librarian of Ptolemy +Euergetes. He was not merely an astronomer and a geographer, but +a poet and grammarian as well. His contemporaries jestingly +called him Beta the Second, because he was said through the +universality of his attainments to be "a second Plato" in +philosophy, "a second Thales" in astronomy, and so on throughout +the list. He was also called the "surveyor of the world," in +recognition of his services to geography. Hipparchus said of him, +perhaps half jestingly, that he had studied astronomy as a +geographer and geography as an astronomer. It is not quite clear +whether the epigram was meant as compliment or as criticism. +Similar phrases have been turned against men of versatile talent +in every age. Be that as it may, Eratosthenes passed into history +as the father of scientific geography and of scientific +chronology; as the astronomer who first measured the obliquity of +the ecliptic; and as the inventive genius who performed the +astounding feat of measuring the size of the globe on which we +live at a time when only a relatively small portion of that +globe's surface was known to civilized man. It is no discredit to +approach astronomy as a geographer and geography as an +astronomer if the results are such as these. What +Eratosthenes really did was to approach both astronomy and +geography from two seemingly divergent points of attack--namely, +from the stand-point of the geometer and also from that of the +poet. Perhaps no man in any age has brought a better combination +of observing and imaginative faculties to the aid of science. + +Nearly all the discoveries of Eratosthenes are associated with +observations of the shadows cast by the sun. We have seen that, +in the study of the heavenly bodies, much depends on the +measurement of angles. Now the easiest way in which angles can be +measured, when solar angles are in question, is to pay attention, +not to the sun itself, but to the shadow that it casts. We saw +that Thales made some remarkable measurements with the aid of +shadows, and we have more than once referred to the gnomon, which +is the most primitive, but which long remained the most +important, of astronomical instruments. It is believed that +Eratosthenes invented an important modification of the gnomon +which was elaborated afterwards by Hipparchus and called an +armillary sphere. This consists essentially of a small gnomon, or +perpendicular post, attached to a plane representing the earth's +equator and a hemisphere in imitation of the earth's surface. +With the aid of this, the shadow cast by the sun could be very +accurately measured. It involves no new principle. Every +perpendicular post or object of any kind placed in the sunlight +casts a shadow from which the angles now in question could be +roughly measured. The province of the armillary sphere was to +make these measurements extremely accurate. + +With the aid of this implement, Eratosthenes carefully noted the +longest and the shortest shadows cast by the gnomon--that is to +say, the shadows cast on the days of the solstices. He found that +the distance between the tropics thus measured represented 47 +degrees 42' 39" of arc. One-half of this, or 23 degrees 5,' +19.5", represented the obliquity of the ecliptic--that is to say, +the angle by which the earth's axis dipped from the perpendicular +with reference to its orbit. This was a most important +observation, and because of its accuracy it has served modern +astronomers well for comparison in measuring the trifling change +due to our earth's slow, swinging wobble. For the earth, be it +understood, like a great top spinning through space, holds its +position with relative but not quite absolute fixity. It must not +be supposed, however, that the experiment in question was quite +new with Eratosthenes. His merit consists rather in the accuracy +with which he made his observation than in the novelty of the +conception; for it is recorded that Eudoxus, a full century +earlier, had remarked the obliquity of the ecliptic. That +observer had said that the obliquity corresponded to the side of +a pentadecagon, or fifteen-sided figure, which is equivalent in +modern phraseology to twenty- four degrees of arc. But so little +is known regarding the way in which Eudoxus reached his estimate +that the measurement of Eratosthenes is usually spoken of as if +it were the first effort of the kind. + +Much more striking, at least in its appeal to the popular +imagination, was that other great feat which Eratosthenes +performed with the aid of his perfected gnomon--the measurement +of the earth itself. When we reflect that at this period the +portion of the earth open to observation extended only from the +Straits of Gibraltar on the west to India on the east, and from +the North Sea to Upper Egypt, it certainly seems enigmatical--at +first thought almost miraculous--that an observer should have +been able to measure the entire globe. That he should have +accomplished this through observation of nothing more than a tiny +bit of Egyptian territory and a glimpse of the sun's shadow makes +it seem but the more wonderful. Yet the method of Eratosthenes, +like many another enigma, seems simple enough once it is +explained. It required but the application of a very elementary +knowledge of the geometry of circles, combined with the use of a +fact or two from local geography--which detracts nothing from the +genius of the man who could reason from such simple premises to +so wonderful a conclusion. + +Stated in a few words, the experiment of Eratosthenes was this. +His geographical studies had taught him that the town of Syene +lay directly south of Alexandria, or, as we should say, on the +same meridian of latitude. He had learned, further, that Syene +lay directly under the tropic, since it was reported that at noon +on the day of the summer solstice the gnomon there cast no +shadow, while a deep well was illumined to the bottom by the sun. +A third item of knowledge, supplied by the surveyors of Ptolemy, +made the distance between Syene and Alexandria five thousand +stadia. These, then, were the preliminary data required by +Eratosthenes. Their significance consists in the fact that here +is a measured bit of the earth's arc five thousand stadia in +length. If we could find out what angle that bit of arc subtends, +a mere matter of multiplication would give us the size of the +earth. But how determine this all-important number? The answer +came through reflection on the relations of concentric circles. +If you draw any number of circles, of whatever size, about a +given centre, a pair of radii drawn from that centre will cut +arcs of the same relative size from all the circles. One circle +may be so small that the actual arc subtended by the radii in a +given case may be but an inch in length, while another circle is +so large that its corresponding are is measured in millions of +miles; but in each case the same number of so-called degrees will +represent the relation of each arc to its circumference. Now, +Eratosthenes knew, as just stated, that the sun, when on the +meridian on the day of the summer solstice, was directly over the +town of Syene. This meant that at that moment a radius of the +earth projected from Syene would point directly towards the sun. +Meanwhile, of course, the zenith would represent the projection +of the radius of the earth passing through Alexandria. All that +was required, then, was to measure, at Alexandria, the angular +distance of the sun from the zenith at noon on the day of the +solstice to secure an approximate measurement of the arc of the +sun's circumference, corresponding to the arc of the earth's +surface represented by the measured distance between Alexandria +and Syene. + +The reader will observe that the measurement could not be +absolutely accurate, because it is made from the surface of the +earth, and not from the earth's centre, but the size of the earth +is so insignificant in comparison with the distance of the sun +that this slight discrepancy could be disregarded. + +The way in which Eratosthenes measured this angle was very +simple. He merely measured the angle of the shadow which his +perpendicular gnomon at Alexandria cast at mid-day on the day of +the solstice, when, as already noted, the sun was directly +perpendicular at Syene. Now a glance at the diagram will make it +clear that the measurement of this angle of the shadow is merely +a convenient means of determining the precisely equal opposite +angle subtending an arc of an imaginary circle passing through +the sun; the are which, as already explained, corresponds with +the arc of the earth's surface represented by the distance +between Alexandria and Syene. He found this angle to represent 7 +degrees 12', or one-fiftieth of the circle. Five thousand stadia, +then, represent one-fiftieth of the earth's circumference; the +entire circumference being, therefore, 250,000 stadia. +Unfortunately, we do not know which one of the various +measurements used in antiquity is represented by the stadia of +Eratosthenes. According to the researches of Lepsius, however, +the stadium in question represented 180 meters, and this would +make the earth, according to the measurement of Eratosthenes, +about twenty-eight thousand miles in circumference, an answer +sufficiently exact to justify the wonder which the experiment +excited in antiquity, and the admiration with which it has ever +since been regarded. + +{illustration caption = DIAGRAM TO ILLUSTRATE ERATOSTHENES' +MEASUREMENT OF THE GLOBE + +FIG. 1. AF is a gnomon at Alexandria; SB a gnomon at Svene; IS +and JK represent the sun's rays. The angle actually measured by +Eratosthenes is KFA, as determined by the shadow cast by the +gnomon AF. This angle is equal to the opposite angle JFL, which +measures the sun's distance from the zenith; and which is also +equal to the angle AES--to determine the Size of which is the +real object of the entire measurement. + +FIG. 2 shows the form of the gnomon actually employed in +antiquity. The hemisphere KA being marked with a scale, it is +obvious that in actual practice Eratosthenes required only to set +his gnomon in the sunlight at the proper moment, and read off the +answer to his problem at a glance. The simplicity of the method +makes the result seem all the more wonderful.} + +Of course it is the method, and not its details or its exact +results, that excites our interest. And beyond question the +method was an admirable one. Its result, however, could not have +been absolutely accurate, because, while correct in principle, +its data were defective. In point of fact Syene did not lie +precisely on the same meridian as Alexandria, neither did it lie +exactly on the tropic. Here, then, are two elements of +inaccuracy. Moreover, it is doubtful whether Eratosthenes made +allowance, as he should have done, for the semi-diameter of the +sun in measuring the angle of the shadow. But these are mere +details, scarcely worthy of mention from our present stand-point. +What perhaps is deserving of more attention is the fact that this +epoch-making measurement of Eratosthenes may not have been the +first one to be made. A passage of Aristotle records that the +size of the earth was said to be 400,000 stadia. Some +commentators have thought that Aristotle merely referred to the +area of the inhabited portion of the earth and not to the +circumference of the earth itself, but his words seem doubtfully +susceptible of this interpretation; and if he meant, as his words +seem to imply, that philosophers of his day had a tolerably +precise idea of the globe, we must assume that this idea was +based upon some sort of measurement. The recorded size, 400,000 +stadia, is a sufficient approximation to the truth to suggest +something more than a mere unsupported guess. Now, since +Aristotle died more than fifty years before Eratosthenes was +born, his report as to the alleged size of the earth certainly +has a suggestiveness that cannot be overlooked; but it arouses +speculations without giving an inkling as to their solution. If +Eratosthenes had a precursor as an earth-measurer, no hint or +rumor has come down to us that would enable us to guess who that +precursor may have been. His personality is as deeply enveloped +in the mists of the past as are the personalities of the great +prehistoric discoverers. For the purpose of the historian, +Eratosthenes must stand as the inventor of the method with which +his name is associated, and as the first man of whom we can say +with certainty that he measured the size of the earth. Right +worthily, then, had the Alexandrian philosopher won his proud +title of "surveyor of the world." + + +HIPPARCHUS, "THE LOVER OF TRUTH" + +Eratosthenes outlived most of his great contemporaries. He saw +the turning of that first and greatest century of Alexandrian +science, the third century before our era. He died in the year +196 B.C., having, it is said, starved himself to death to escape +the miseries of blindness;--to the measurer of shadows, life +without light seemed not worth the living. Eratosthenes left no +immediate successor. A generation later, however, another great +figure appeared in the astronomical world in the person of +Hipparchus, a man who, as a technical observer, had perhaps no +peer in the ancient world: one who set so high a value upon +accuracy of observation as to earn the title of "the lover of +truth." Hipparchus was born at Nicaea, in Bithynia, in the year +160 B.C. His life, all too short for the interests of science, +ended in the year 125 B.C. The observations of the great +astronomer were made chiefly, perhaps entirely, at Rhodes. A +misinterpretation of Ptolemy's writings led to the idea that +Hipparchus, performed his chief labors in Alexandria, but it is +now admitted that there is no evidence for this. Delambre +doubted, and most subsequent writers follow him here, whether +Hipparchus ever so much as visited Alexandria. In any event there +seems to be no question that Rhodes may claim the honor of being +the chief site of his activities. + +It was Hipparchus whose somewhat equivocal comment on the work of +Eratosthenes we have already noted. No counter-charge in kind +could be made against the critic himself; he was an astronomer +pure and simple. His gift was the gift of accurate observation +rather than the gift of imagination. No scientific progress is +possible without scientific guessing, but Hipparchus belonged to +that class of observers with whom hypothesis is held rigidly +subservient to fact. It was not to be expected that his mind +would be attracted by the heliocentric theory of Aristarchus. He +used the facts and observations gathered by his great predecessor +of Samos, but he declined to accept his theories. For him the +world was central; his problem was to explain, if he could, the +irregularities of motion which sun, moon, and planets showed in +their seeming circuits about the earth. Hipparchus had the gnomon +of Eratosthenes--doubtless in a perfected form--to aid him, and +he soon proved himself a master in its use. For him, as we have +said, accuracy was everything; this was the one element that led +to all his great successes. + +Perhaps his greatest feat was to demonstrate the eccentricity of +the sun's seeming orbit. We of to-day, thanks to Keppler and his +followers, know that the earth and the other planetary bodies in +their circuit about the sun describe an ellipse and not a circle. +But in the day of Hipparchus, though the ellipse was recognized +as a geometrical figure (it had been described and named along +with the parabola and hyperbola by Apollonius of Perga, the pupil +of Euclid), yet it would have been the rankest heresy to suggest +an elliptical course for any heavenly body. A metaphysical +theory, as propounded perhaps by the Pythagoreans but ardently +supported by Aristotle, declared that the circle is the perfect +figure, and pronounced it inconceivable that the motions of the +spheres should be other than circular. This thought dominated the +mind of Hipparchus, and so when his careful measurements led him +to the discovery that the northward and southward journeyings of +the sun did not divide the year into four equal parts, there was +nothing open to him but to either assume that the earth does not +lie precisely at the centre of the sun's circular orbit or to +find some alternative hypothesis. + +In point of fact, the sun (reversing the point of view in +accordance with modern discoveries) does lie at one focus of the +earth's elliptical orbit, and therefore away from the physical +centre of that orbit; in other words, the observations of +Hipparchus were absolutely accurate. He was quite correct in +finding that the sun spends more time on one side of the equator +than on the other. When, therefore, he estimated the relative +distance of the earth from the geometrical centre of the sun's +supposed circular orbit, and spoke of this as the measure of the +sun's eccentricity, he propounded a theory in which true data of +observation were curiously mingled with a positively inverted +theory. That the theory of Hipparchus was absolutely consistent +with all the facts of this particular observation is the best +evidence that could be given of the difficulties that stood in +the way of a true explanation of the mechanism of the heavens. + +But it is not merely the sun which was observed to vary in the +speed of its orbital progress; the moon and the planets also show +curious accelerations and retardations of motion. The moon in +particular received most careful attention from Hipparchus. +Dominated by his conception of the perfect spheres, he could find +but one explanation of the anomalous motions which he observed, +and this was to assume that the various heavenly bodies do not +fly on in an unvarying arc in their circuit about the earth, but +describe minor circles as they go which can be likened to nothing +so tangibly as to a light attached to the rim of a wagon-wheel in +motion. If such an invisible wheel be imagined as carrying the +sun, for example, on its rim, while its invisible hub follows +unswervingly the circle of the sun's mean orbit (this wheel, be +it understood, lying in the plane of the orbit, not at right- +angles to it), then it must be obvious that while the hub remains +always at the same distance from the earth, the circling rim will +carry the sun nearer the earth, then farther away, and that while +it is traversing that portion of the are which brings it towards +the earth, the actual forward progress of the sun will be +retarded notwithstanding the uniform motion of the hub, just as +it will be accelerated in the opposite arc. Now, if we suppose +our sun-bearing wheel to turn so slowly that the sun revolves but +once about its imaginary hub while the wheel itself is making the +entire circuit of the orbit, we shall have accounted for the +observed fact that the sun passes more quickly through one-half +of the orbit than through the other. Moreover, if we can +visualize the process and imagine the sun to have left a visible +line of fire behind him throughout the course, we shall see that +in reality the two circular motions involved have really resulted +in producing an elliptical orbit. + +The idea is perhaps made clearer if we picture the actual +progress of the lantern attached to the rim of an ordinary +cart-wheel. When the cart is drawn forward the lantern is made to +revolve in a circle as regards the hub of the wheel, but since +that hub is constantly going forward, the actual path described +by the lantern is not a circle at all but a waving line. It is +precisely the same with the imagined course of the sun in its +orbit, only that we view these lines just as we should view the +lantern on the wheel if we looked at it from directly above and +not from the side. The proof that the sun is describing this +waving line, and therefore must be considered as attached to an +imaginary wheel, is furnished, as it seemed to Hipparchus, by the +observed fact of the sun's varying speed. + +That is one way of looking at the matter. It is an hypothesis +that explains the observed facts--after a fashion, and indeed a +very remarkable fashion. The idea of such an explanation did not +originate with Hipparchus. The germs of the thought were as old +as the Pythagorean doctrine that the earth revolves about a +centre that we cannot see. Eudoxus gave the conception greater +tangibility, and may be considered as the father of this doctrine +of wheels--epicycles, as they came to be called. Two centuries +before the time of Hipparchus he conceived a doctrine of spheres +which Aristotle found most interesting, and which served to +explain, along the lines we have just followed, the observed +motions of the heavenly bodies. Calippus, the reformer of the +calendar, is said to have carried an account of this theory to +Aristotle. As new irregularities of motion of the sun, moon, and +planetary bodies were pointed out, new epicycles were invented. +There is no limit to the number of imaginary circles that may be +inscribed about an imaginary centre, and if we conceive each one +of these circles to have a proper motion of its own, and each one +to carry the sun in the line of that motion, except as it is +diverted by the other motions--if we can visualize this complex +mingling of wheels--we shall certainly be able to imagine the +heavenly body which lies at the juncture of all the rims, as +being carried forward in as erratic and wobbly a manner as could +be desired. In other words, the theory of epicycles will account +for all the facts of the observed motions of all the heavenly +bodies, but in so doing it fills the universe with a most +bewildering network of intersecting circles. Even in the time of +Calippus fifty-five of these spheres were computed. + +We may well believe that the clear-seeing Aristarchus would look +askance at such a complex system of imaginary machinery. But +Hipparchus, pre-eminently an observer rather than a theorizer, +seems to have been content to accept the theory of epicycles as +he found it, though his studies added to its complexities; and +Hipparchus was the dominant scientific personality of his +century. What he believed became as a law to his immediate +successors. His tenets were accepted as final by their great +popularizer, Ptolemy, three centuries later; and so the +heliocentric theory of Aristarchus passed under a cloud almost at +the hour of its dawning, there to remain obscured and forgotten +for the long lapse of centuries. A thousand pities that the +greatest observing astronomer of antiquity could not, like one of +his great precursors, have approached astronomy from the +stand-point of geography and poetry. Had he done so, perhaps he +might have reflected, like Aristarchus before him, that it seems +absurd for our earth to hold the giant sun in thraldom; then +perhaps his imagination would have reached out to the +heliocentric doctrine, and the cobweb hypothesis of epicycles, +with that yet more intangible figment of the perfect circle, +might have been wiped away. + +But it was not to be. With Aristarchus the scientific imagination +had reached its highest flight; but with Hipparchus it was +beginning to settle back into regions of foggier atmosphere and +narrower horizons. For what, after all, does it matter that +Hipparchus should go on to measure the precise length of the year +and the apparent size of the moon's disk; that he should make a +chart of the heavens showing the place of 1080 stars; even that +he should discover the precession of the equinox;--what, after +all, is the significance of these details as against the +all-essential fact that the greatest scientific authority of his +century--the one truly heroic scientific figure of his +epoch--should have lent all the forces of his commanding +influence to the old, false theory of cosmology, when the true +theory had been propounded and when he, perhaps, was the only man +in the world who might have substantiated and vitalized that +theory? It is easy to overestimate the influence of any single +man, and, contrariwise, to underestimate the power of the +Zeitgeist. But when we reflect that the doctrines of Hipparchus, +as promulgated by Ptolemy, became, as it were, the last word of +astronomical science for both the Eastern and Western worlds, and +so continued after a thousand years, it is perhaps not too much +to say that Hipparchus, "the lover of truth," missed one of the +greatest opportunities for the promulgation of truth ever +vouchsafed to a devotee of pure science. + +But all this, of course, detracts nothing from the merits of +Hipparchus as an observing astronomer. A few words more must be +said as to his specific discoveries in this field. According to +his measurement, the tropic year consists of 365 days, 5 hours, +and 49 minutes, varying thus only 12 seconds from the true year, +as the modern astronomer estimates it. Yet more remarkable, +because of the greater difficulties involved, was Hipparchus's +attempt to measure the actual distance of the moon. Aristarchus +had made a similar attempt before him. Hipparchus based his +computations on studies of the moon in eclipse, and he reached +the conclusion that the distance of the moon is equal to 59 radii +of the earth (in reality it is 60.27 radii). Here, then, was the +measure of the base-line of that famous triangle with which +Aristarchus had measured the distance of the sun. Hipparchus must +have known of that measurement, since he quotes the work of +Aristarchus in other fields. Had he now but repeated the +experiment of Aristarchus, with his perfected instruments and his +perhaps greater observational skill, he was in position to +compute the actual distance of the sun in terms not merely of the +moon's distance but of the earth's radius. And now there was the +experiment of Eratosthenes to give the length of that radius in +precise terms. In other words, Hipparchus might have measured the +distance of the sun in stadia. But if he had made the +attempt--and, indeed, it is more than likely that he did so--the +elements of error in his measurements would still have kept him +wide of the true figures. + +The chief studies of Hipparchus were directed, as we have seen, +towards the sun and the moon, but a phenomenon that occurred in +the year 134 B.C. led him for a time to give more particular +attention to the fixed stars. The phenomenon in question was the +sudden outburst of a new star; a phenomenon which has been +repeated now and again, but which is sufficiently rare and +sufficiently mysterious to have excited the unusual attention of +astronomers in all generations. Modern science offers an +explanation of the phenomenon, as we shall see in due course. We +do not know that Hipparchus attempted to explain it, but he was +led to make a chart of the heavens, probably with the idea of +guiding future observers in the observation of new stars. Here +again Hipparchus was not altogether an innovator, since a chart +showing the brightest stars had been made by Eratosthenes; but +the new charts were much elaborated. + +The studies of Hipparchus led him to observe the stars chiefly +with reference to the meridian rather than with reference to +their rising, as had hitherto been the custom. In making these +studies of the relative position of the stars, Hipparchus was led +to compare his observations with those of the Babylonians, which, +it was said, Alexander had caused to be transmitted to Greece. He +made use also of the observations of Aristarchus and others of +his Greek precursors. The result of his comparisons proved that +the sphere of the fixed stars had apparently shifted its position +in reference to the plane of the sun's orbit--that is to say, the +plane of the ecliptic no longer seemed to cut the sphere of the +fixed stars at precisely the point where the two coincided in +former centuries. The plane of the ecliptic must therefore be +conceived as slowly revolving in such a way as gradually to +circumnavigate the heavens. This important phenomenon is +described as the precession of the equinoxes. + +It is much in question whether this phenomenon was not known to +the ancient Egyptian astronomers; but in any event, Hipparchus is +to be credited with demonstrating the fact and making it known to +the Western world. A further service was rendered theoretical +astronomy by Hipparchus through his invention of the planosphere, +an instrument for the representation of the mechanism of the +heavens. His computations of the properties of the spheres led +him also to what was virtually a discovery of the method of +trigonometry, giving him, therefore, a high position in the field +of mathematics. All in all, then, Hipparchus is a most heroic +figure. He may well be considered the greatest star-gazer of +antiquity, though he cannot, without injustice to his great +precursors, be allowed the title which is sometimes given him of +"father of systematic astronomy." + + +CTESIBIUS AND HERO: MAGICIANS OF ALEXANDRIA + +Just about the time when Hipparchus was working out at Rhodes his +puzzles of celestial mechanics, there was a man in Alexandria who +was exercising a strangely inventive genius over mechanical +problems of another sort; a man who, following the example set by +Archimedes a century before, was studying the problems of matter +and putting his studies to practical application through the +invention of weird devices. The man's name was Ctesibius. We know +scarcely more of him than that he lived in Alexandria, probably +in the first half of the second century B.C. His antecedents, the +place and exact time of his birth and death, are quite unknown. +Neither are we quite certain as to the precise range of his +studies or the exact number of his discoveries. It appears that +he had a pupil named Hero, whose personality, unfortunately, is +scarcely less obscure than that of his master, but who wrote a +book through which the record of the master's inventions was +preserved to posterity. Hero, indeed, wrote several books, though +only one of them has been preserved. The ones that are lost bear +the following suggestive titles: On the Construction of Slings; +On the Construction of Missiles; On the Automaton; On the Method +of Lifting Heavy Bodies; On the Dioptric or Spying-tube. The work +that remains is called Pneumatics, and so interesting a work it +is as to make us doubly regret the loss of its companion volumes. +Had these other books been preserved we should doubtless have a +clearer insight than is now possible into some at least of the +mechanical problems that exercised the minds of the ancient +philosophers. The book that remains is chiefly concerned, as its +name implies, with the study of gases, or, rather, with the study +of a single gas, this being, of course, the air. But it tells us +also of certain studies in the dynamics of water that are most +interesting, and for the historian of science most important. + +Unfortunately, the pupil of Ctesibius, whatever his ingenuity, +was a man with a deficient sense of the ethics of science. He +tells us in his preface that the object of his book is to record +some ingenious discoveries of others, together with additional +discoveries of his own, but nowhere in the book itself does he +give us the, slightest clew as to where the line is drawn between +the old and the new. Once, in discussing the weight of water, he +mentions the law of Archimedes regarding a floating body, but +this is the only case in which a scientific principle is traced +to its source or in which credit is given to any one for a +discovery. This is the more to be regretted because Hero has +discussed at some length the theories involved in the treatment +of his subject. This reticence on the part of Hero, combined with +the fact that such somewhat later writers as Pliny and Vitruvius +do not mention Hero's name, while they frequently mention the +name of his master, Ctesibius, has led modern critics to a +somewhat sceptical attitude regarding the position of Hero as an +actual discoverer. + +The man who would coolly appropriate some discoveries of others +under cloak of a mere prefatorial reference was perhaps an +expounder rather than an innovator, and had, it is shrewdly +suspected, not much of his own to offer. Meanwhile, it is +tolerably certain that Ctesibius was the discoverer of the +principle of the siphon, of the forcing-pump, and of a pneumatic +organ. An examination of Hero's book will show that these are +really the chief principles involved in most of the various +interesting mechanisms which he describes. We are constrained, +then, to believe that the inventive genius who was really +responsible for the mechanisms we are about to describe was +Ctesibius, the master. Yet we owe a debt of gratitude to Hero, +the pupil, for having given wider vogue to these discoveries, and +in particular for the discussion of the principles of +hydrostatics and pneumatics contained in the introduction to his +book. This discussion furnishes us almost our only knowledge as +to the progress of Greek philosophers in the field of mechanics +since the time of Archimedes. + +The main purpose of Hero in his preliminary thesis has to do with +the nature of matter, and recalls, therefore, the studies of +Anaxagoras and Democritus. Hero, however, approaches his subject +from a purely material or practical stand-point. He is an +explicit champion of what we nowadays call the molecular theory +of matter. "Every body," he tells us, "is composed of minute +particles, between which are empty spaces less than these +particles of the body. It is, therefore, erroneous to say that +there is no vacuum except by the application of force, and that +every space is full either of air or water or some other +substance. But in proportion as any one of these particles +recedes, some other follows it and fills the vacant space; +therefore there is no continuous vacuum, except by the +application of some force [like suction]--that is to say, an +absolute vacuum is never found, except as it is produced +artificially." Hero brings forward some thoroughly convincing +proofs of the thesis he is maintaining. "If there were no void +places between the particles of water," he says, "the rays of +light could not penetrate the water; moreover, another liquid, +such as wine, could not spread itself through the water, as it is +observed to do, were the particles of water absolutely +continuous." The latter illustration is one the validity of which +appeals as forcibly to the physicists of to-day as it did to +Hero. The same is true of the argument drawn from the +compressibility of gases. Hero has evidently made a careful study +of this subject. He knows that an inverted tube full of air may +be immersed in water without becoming wet on the inside, proving +that air is a physical substance; but he knows also that this +same air may be caused to expand to a much greater bulk by the +application of heat, or may, on the other hand, be condensed by +pressure, in which case, as he is well aware, the air exerts +force in the attempt to regain its normal bulk. But, he argues, +surely we are not to believe that the particles of air expand to +fill all the space when the bulk of air as a whole expands under +the influence of heat; nor can we conceive that the particles of +normal air are in actual contact, else we should not be able to +compress the air. Hence his conclusion, which, as we have seen, +he makes general in its application to all matter, that there are +spaces, or, as he calls them, vacua, between the particles that +go to make up all substances, whether liquid, solid, or gaseous. + +Here, clearly enough, was the idea of the "atomic" nature of +matter accepted as a fundamental notion. The argumentative +attitude assumed by Hero shows that the doctrine could not be +expected to go unchallenged. But, on the other hand, there is +nothing in his phrasing to suggest an intention to claim +originality for any phase of the doctrine. We may infer that in +the three hundred years that had elapsed since the time of +Anaxagoras, that philosopher's idea of the molecular nature of +matter had gained fairly wide currency. As to the expansive power +of gas, which Hero describes at some length without giving us a +clew to his authorities, we may assume that Ctesibius was an +original worker, yet the general facts involved were doubtless +much older than his day. Hero, for example, tells us of the +cupping-glass used by physicians, which he says is made into a +vacuum by burning up the air in it; but this apparatus had +probably been long in use, and Hero mentions it not in order to +describe the ordinary cupping-glass which is referred to, but a +modification of it. He refers to the old form as if it were +something familiar to all. + +Again, we know that Empedocles studied the pressure of the air in +the fifth century B.C., and discovered that it would support a +column of water in a closed tube, so this phase of the subject is +not new. But there is no hint anywhere before this work of Hero +of a clear understanding that the expansive properties of the air +when compressed, or when heated, may be made available as a motor +power. Hero, however, has the clearest notions on the subject and +puts them to the practical test of experiment. Thus he constructs +numerous mechanisms in which the expansive power of air under +pressure is made to do work, and others in which the same end is +accomplished through the expansive power of heated air. For +example, the doors of a temple are made to swing open +automatically when a fire is lighted on a distant altar, closing +again when the fire dies out--effects which must have filled the +minds of the pious observers with bewilderment and wonder, +serving a most useful purpose for the priests, who alone, we may +assume, were in the secret. There were two methods by which this +apparatus was worked. In one the heated air pressed on the water +in a close retort connected with the altar, forcing water out of +the retort into a bucket, which by its weight applied a force +through pulleys and ropes that turned the standards on which the +temple doors revolved. When the fire died down the air +contracted, the water was siphoned back from the bucket, which, +being thus lightened, let the doors close again through the +action of an ordinary weight. The other method was a slight +modification, in which the retort of water was dispensed with and +a leather sack like a large football substitued. The ropes +and pulleys were connected with this sack, which exerted a pull +when the hot air expanded, and which collapsed and thus relaxed +its strain when the air cooled. A glance at the illustrations +taken from Hero's book will make the details clear. + +Other mechanisms utilized a somewhat different combination of +weights, pulleys, and siphons, operated by the expansive power of +air, unheated but under pressure, such pressure being applied +with a force- pump, or by the weight of water running into a +closed receptacle. One such mechanism gives us a constant jet of +water or perpetual fountain. Another curious application of the +principle furnishes us with an elaborate toy, consisting of a +group of birds which alternately whistle or are silent, while an +owl seated on a neighboring perch turns towards the birds when +their song begins and away from them when it ends. The "singing" +of the birds, it must be explained, is produced by the expulsion +of air through tiny tubes passing up through their throats from a +tank below. The owl is made to turn by a mechanism similar to +that which manipulates the temple doors. The pressure is supplied +merely by a stream of running water, and the periodical silence +of the birds is due to the fact that this pressure is relieved +through the automatic siphoning off of the water when it reaches +a certain height. The action of the siphon, it may be added, is +correctly explained by Hero as due to the greater weight of the +water in the longer arm of the bent tube. As before mentioned, +the siphon is repeatedly used in these mechanisms of Hero. The +diagram will make clear the exact application of it in the +present most ingenious mechanism. We may add that the principle +of the whistle was a favorite one of Hero. By the aid of a +similar mechanism he brought about the blowing of trumpets when +the temple doors were opened, a phenomenon which must greatly +have enhanced the mystification. It is possible that this +principle was utilized also in connection with statues to produce +seemingly supernatural effects. This may be the explanation of +the tradition of the speaking statue in the temple of Ammon at +Thebes. + +{illustration caption = DEVICE FOR CAUSING THE DOORS OF THE +TEMPLE TO OPEN WHEN THE FIRE ON THE ALTAR IS LIGHTED (Air heated +in the altar F drives water from the closed receptacle H through +the tube KL into the bucket M, which descends through gravity, +thus opening the doors. When the altar cools, the air contracts, +the water is sucked from the bucket, and the weight and pulley +close the doors.)} + +{illustration caption = THE STEAM-ENGINE OF HERO (The steam +generated in the receptacle AB passes through the tube EF into +the globe, and escapes through the bent tubes H and K, causing +the globe to rotate on the axis LG.)} + + +The utilization of the properties of compressed air was not +confined, however, exclusively to mere toys, or to produce +miraculous effects. The same principle was applied to a practical +fire-engine, worked by levers and force-pumps; an apparatus, in +short, altogether similar to that still in use in rural +districts. A slightly different application of the motive power +of expanding air is furnished in a very curious toy called "the +dancing figures." In this, air heated in a retort like a +miniature altar is allowed to escape through the sides of two +pairs of revolving arms precisely like those of the ordinary +revolving fountain with which we are accustomed to water our +lawns, the revolving arms being attached to a plane on which +several pairs of statuettes representing dancers are placed, An +even more interesting application of this principle of setting a +wheel in motion is furnished in a mechanism which must be +considered the earliest of steam-engines. Here, as the name +implies, the gas supplying the motive power is actually steam. +The apparatus made to revolve is a globe connected with the +steam-retort by a tube which serves as one of its axes, the steam +escaping from the globe through two bent tubes placed at either +end of an equatorial diameter. It does not appear that Hero had +any thought of making practical use of this steam- engine. It was +merely a curious toy--nothing more. Yet had not the age that +succeeded that of Hero been one in which inventive genius was +dormant, some one must soon have hit upon the idea that this +steam- engine might be improved and made to serve a useful +purpose. As the case stands, however, there was no advance made +upon the steam motor of Hero for almost two thousand years. And, +indeed, when the practical application of steam was made, towards +the close of the eighteenth century, it was made probably quite +without reference to the experiment of Hero, though knowledge of +his toy may perhaps have given a clew to Watt or his +predecessors. + + +{illustration caption = THE SLOT-MACHINE OF HERO (The coin +introduced at A falls on the lever R, and by its weight opens the +valve S, permitting the liquid to escape through the invisible +tube LM. As the lever tips, the coin slides off and the valve +closes. The liquid in tank must of course be kept above F.)} + +In recent times there has been a tendency to give to this +steam-engine of Hero something more than full meed of +appreciation. To be sure, it marked a most important principle in +the conception that steam might be used as a motive power, but, +except in the demonstration of this principle, the mechanism of +Hero was much too primitive to be of any importance. But there is +one mechanism described by Hero which was a most explicit +anticipation of a device, which presumably soon went out of use, +and which was not reinvented until towards the close of the +nineteenth century. This was a device which has become familiar +in recent times as the penny-in-the-slot machine. When towards +the close of the nineteenth century some inventive craftsman hit +upon the idea of an automatic machine to supply candy, a box of +cigarettes, or a whiff of perfumery, he may or may not have +borrowed his idea from the slot-machine of Hero; but in any +event, instead of being an innovator he was really two thousand +years behind the times, for the slot-machine of Hero is the +precise prototype of these modern ones. + +The particular function which the mechanism of Hero was destined +to fulfil was the distribution of a jet of water, presumably used +for sacramental purposes, which was given out automatically when +a five- drachma coin was dropped into the slot at the top of the +machine. The internal mechanism of the machine was simple enough, +consisting merely of a lever operating a valve which was opened +by the weight of the coin dropping on the little shelf at the end +of the lever, and which closed again when the coin slid off the +shelf. The illustration will show how simple this mechanism was. +Yet to the worshippers, who probably had entered the temple +through doors miraculously opened, and who now witnessed this +seemingly intelligent response of a machine, the result must have +seemed mystifying enough; and, indeed, for us also, when we +consider how relatively crude was the mechanical knowledge of the +time, this must seem nothing less than marvellous. As in +imagination we walk up to the sacred tank, drop our drachma in +the slot, and hold our hand for the spurt of holy-water, can we +realize that this is the land of the Pharaohs, not England or +America; that the kingdom of the Ptolemies is still at its +height; that the republic of Rome is mistress of the world; that +all Europe north of the Alps is inhabited solely by barbarians; +that Cleopatra and Julius Caesar are yet unborn; that the +Christian era has not yet begun? Truly, it seems as if there +could be no new thing under the sun. + + + +X. SCIENCE OF THE ROMAN PERIOD + +We have seen that the third century B.C. was a time when +Alexandrian science was at its height, but that the second +century produced also in Hipparchus at least one investigator of +the very first rank; though, to be sure, Hipparchus can be called +an Alexandrian only by courtesy. In the ensuing generations the +Greek capital at the mouth of the Nile continued to hold its +place as the centre of scientific and philosophical thought. The +kingdom of the Ptolemies still flourished with at least the +outward appearances of its old-time glory, and a company of +grammarians and commentators of no small merit could always be +found in the service of the famous museum and library; but the +whole aspect of world-history was rapidly changing. Greece, after +her brief day of political supremacy, was sinking rapidly +into desuetude, and the hard-headed Roman in the West was making +himself master everywhere. While Hipparchus of Rhodes was in his +prime, Corinth, the last stronghold of the main-land of Greece, +had fallen before the prowess of the Roman, and the kingdom of +the Ptolemies, though still nominally free, had begun to come +within the sphere of Roman influence. + +Just what share these political changes had in changing the +aspect of Greek thought is a question regarding which difference +of opinion might easily prevail; but there can be no question +that, for one reason or another, the Alexandrian school as a +creative centre went into a rapid decline at about the time of +the Roman rise to world-power. There are some distinguished +names, but, as a general rule, the spirit of the times is +reminiscent rather than creative; the workers tend to collate the +researches of their predecessors rather than to make new and +original researches for themselves. Eratosthenes, the inventive +world-measurer, was succeeded by Strabo, the industrious collator +of facts; Aristarchus and Hipparchus, the originators of new +astronomical methods, were succeeded by Ptolemy, the perfecter of +their methods and the systematizer of their knowledge. Meanwhile, +in the West, Rome never became a true culture-centre. The great +genius of the Roman was political; the Augustan Age produced a +few great historians and poets, but not a single great +philosopher or creative devotee of science. Cicero, Lucian, +Seneca, Marcus Aurelius, give us at best a reflection of Greek +philosophy. Pliny, the one world-famous name in the scientific +annals of Rome, can lay claim to no higher credit than that of a +marvellously industrious collector of facts--the compiler of an +encyclopaedia which contains not one creative touch. + +All in all, then, this epoch of Roman domination is one that need +detain the historian of science but a brief moment. With the +culmination of Greek effort in the so-called Hellenistic period +we have seen ancient science at its climax. The Roman period is +but a time of transition, marking, as it were, a plateau on the +slope between those earlier heights and the deep, dark valleys of +the Middle Ages. Yet we cannot quite disregard the efforts of +such workers as those we have just named. Let us take a more +specific glance at their accomplishments. + + +STRABO THE GEOGRAPHER + +The earliest of these workers in point of time is Strabo. This +most famous of ancient geographers was born in Amasia, Pontus, +about 63 B.C., and lived to the year 24 A.D., living, therefore, +in the age of Caesar and Augustus, during which the final +transformation in the political position of the kingdom of Egypt +was effected. The name of Strabo in a modified form has become +popularized through a curious circumstance. The geographer, it +appears, was afflicted with a peculiar squint of the eyes, hence +the name strabismus, which the modern oculist applies to that +particular infirmity. + +Fortunately, the great geographer has not been forced to depend +upon hearsay evidence for recognition. His comprehensive work on +geography has been preserved in its entirety, being one of the +few expansive classical writings of which this is true. The other +writings of Strabo, however, including certain histories of which +reports have come down to us, are entirely lost. The geography is +in many ways a remarkable book. It is not, however, a work in +which any important new principles are involved. Rather is it +typical of its age in that it is an elaborate compilation and a +critical review of the labors of Strabo's predecessors. Doubtless +it contains a vast deal of new information as to the details of +geography--precise areas and distance, questions of geographical +locations as to latitude and zones, and the like. But however +important these details may have been from a contemporary +stand-point, they, of course, can have nothing more than +historical interest to posterity. The value of the work from our +present stand-point is chiefly due to the criticisms which Strabo +passes upon his forerunners, and to the incidental historical and +scientific references with which his work abounds. Being written +in this closing period of ancient progress, and summarizing, as +it does, in full detail the geographical knowledge of the time, +it serves as an important guide-mark for the student of the +progress of scientific thought. We cannot do better than briefly +to follow Strabo in his estimates and criticisms of the work of +his predecessors, taking note thus of the point of view from +which he himself looked out upon the world. We shall thus gain a +clear idea as to the state of scientific geography towards the +close of the classical epoch. + +"If the scientific investigation of any subject be the proper +avocation of the philosopher," says Strabo, "geography, the +science of which we propose to treat, is certainly entitled to a +high place; and this is evident from many considerations. They +who first undertook to handle the matter were distinguished men. +Homer, Anaximander the Milesian, and Hecaeus (his fellow-citizen +according to Eratosthenes), Democritus, Eudoxus, Dicaearchus, and +Ephorus, with many others, and after these, Eratosthenes, +Polybius, and Posidonius, all of them philosophers. Nor is the +great learning through which alone this subject can be approached +possessed by any but a person acquainted with both human and +divine things, and these attainments constitute what is called +philosophy. In addition to its vast importance in regard to +social life and the art of government, geography unfolds to us a +celestial phenomena, acquaints us with the occupants of the land +and ocean, and the vegetation, fruits, and peculiarities of the +various quarters of the earth, a knowledge of which marks him who +cultivates it as a man earnest in the great problem of life and +happiness." + +Strabo goes on to say that in common with other critics, +including Hipparchus, he regards Homer as the first great +geographer. He has much to say on the geographical knowledge of +the bard, but this need not detain us. We are chiefly concerned +with his comment upon his more recent predecessors, beginning +with Eratosthenes. The constant reference to this worker shows +the important position which he held. Strabo appears neither as +detractor nor as partisan, but as one who earnestly desires the +truth. Sometimes he seems captious in his criticisms regarding +some detail, nor is he always correct in his emendations of the +labors of others; but, on the whole, his work is marked by an +evident attempt at fairness. In reading his book, however, one is +forced to the conclusion that Strabo is an investigator of +details, not an original thinker. He seems more concerned with +precise measurements than with questionings as to the open +problems of his science. Whatever he accepts, then, may be taken +as virtually the stock doctrine of the period. + +"As the size of the earth," he says, "has been demonstrated by +other writers, we shall here take for granted and receive as +accurate what they have advanced. We shall also assume that the +earth is spheroidal, that its surface is likewise spheroidal and, +above all, that bodies have a tendency towards its centre, which +latter point is clear to the perception of the most average +understanding. However, we may show summarily that the earth is +spheroidal, from the consideration that all things, however +distant, tend to its centre, and that every body is attracted +towards its centre by gravity. This is more distinctly proved +from observations of the sea and sky, for here the evidence of +the senses and common observation is alone requisite. The +convexity of the sea is a further proof of this to those who have +sailed, for they cannot perceive lights at a distance when placed +at the same level as their eyes, and if raised on high they at +once become perceptible to vision though at the same time farther +removed. So when the eye is raised it sees what before was +utterly imperceptible. Homer speaks of this when he says: + + +" 'Lifted up on the vast wave he quickly beheld afar.' + +Sailors as they approach their destination behold the shore +continually raising itself to their view, and objects which had +at first seemed low begin to lift themselves. Our gnomons, also, +are, among other things, evidence of the revolution of the +heavenly bodies, and common-sense at once shows us that if the +depth of the earth were infinite such a revolution could not take +place."[1] + +Elsewhere Strabo criticises Eratosthenes for having entered into +a long discussion as to the form of the earth. This matter, +Strabo thinks, "should have been disposed of in the compass of a +few words." Obviously this doctrine of the globe's sphericity +had, in the course of 600 years, become so firmly established +among the Greek thinkers as to seem almost axiomatic. We shall +see later on how the Western world made a curious recession from +this seemingly secure position under stimulus of an Oriental +misconception. As to the size of the globe, Strabo is disposed to +accept without particular comment the measurements of +Eratosthenes. He speaks, however, of "more recent measurements," +referring in particular to that adopted by Posidonius, according +to which the circumference is only about one hundred and eighty +thousand stadia. Posidonius, we may note in passing, was a +contemporary and friend of Cicero, and hence lived shortly before +the time of Strabo. His measurement of the earth was based on +observations of a star which barely rose above the southern +horizon at Rhodes as compared with the height of the same star +when observed at Alexandria. This measurement of Posidonius, +together with the even more famous measurement of Eratosthenes, +appears to have been practically the sole guide as to the size of +the earth throughout the later periods of antiquity, and, indeed, +until the later Middle Ages. + +As becomes a writer who is primarily geographer and historian +rather than astronomer, Strabo shows a much keener interest in +the habitable portions of the globe than in the globe as a whole. +He assures us that this habitable portion of the earth is a great +island, "since wherever men have approached the termination of +the land, the sea, which we designate ocean, has been met with, +and reason assures us of the similarity of this place which our +senses have not been tempted to survey." He points out that +whereas sailors have not circumnavigated the globe, that they had +not been prevented from doing so by any continent, and it seems +to him altogether unlikely that the Atlantic Ocean is divided +into two seas by narrow isthmuses so placed as to prevent +circumnavigation. "How much more probable that it is confluent +and uninterrupted. This theory," he adds, "goes better with the +ebb and flow of the ocean. Moreover (and here his reasoning +becomes more fanciful), the greater the amount of moisture +surrounding the earth, the easier would the heavenly bodies be +supplied with vapor from thence." Yet he is disposed to believe, +following Plato, that the tradition "concerning the island of +Atlantos might be received as something more than idle fiction, +it having been related by Solon, on the authority of the Egyptian +priests, that this island, almost as large as a continent, was +formerly in existence although now it had disappeared."[2] + +In a word, then, Strabo entertains no doubt whatever that it +would be possible to sail around the globe from Spain to India. +Indeed, so matter-of-fact an inference was this that the feat of +Columbus would have seemed less surprising in the first century +of our era than it did when actually performed in the fifteenth +century. The terrors of the great ocean held the mariner back, +rather than any doubt as to where he would arrive at the end of +the voyage. + +Coupled with the idea that the habitable portion of the earth is +an island, there was linked a tolerably definite notion as to the +shape of this island. This shape Strabo likens to a military +cloak. The comparison does not seem peculiarly apt when we are +told presently that the length of the habitable earth is more +than twice its breadth. This idea, Strabo assures us, accords +with the most accurate observations "both ancient and modern." +These observations seemed to show that it is not possible to live +in the region close to the equator, and that, on the other hand, +the cold temperature sharply limits the habitability of the globe +towards the north. All the civilization of antiquity clustered +about the Mediterranean, or extended off towards the east at +about the same latitude. Hence geographers came to think of the +habitable globe as having the somewhat lenticular shape which a +crude map of these regions suggests. We have already had occasion +to see that at an earlier day Anaxagoras was perhaps influenced +in his conception of the shape of the earth by this idea, and the +constant references of Strabo impress upon us the thought that +this long, relatively narrow area of the earth's surface is the +only one which can be conceived of as habitable. + +Strabo had much to tell us concerning zones, which, following +Posidonius, he believes to have been first described by +Parmenides. We may note, however, that other traditions assert +that both Thales and Pythagoras had divided the earth into zones. +The number of zones accepted by Strabo is five, and he +criticises Polybius for making the number six. The five +zones accepted by Strabo are as follows: the uninhabitable torrid +zone lying in the region of the equator; a zone on either side of +this extending to the tropic; and then the temperate zones +extending in either direction from the tropic to the arctic +regions. There seems to have been a good deal of dispute among +the scholars of the time as to the exact arrangement of these +zones, but the general idea that the north-temperate zone is the +part of the earth with which the geographer deals seemed clearly +established. That the south-temperate zone would also present a +habitable area is an idea that is sometimes suggested, though +seldom or never distinctly expressed. It is probable that +different opinions were held as to this, and no direct evidence +being available, a cautiously scientific geographer like Strabo +would naturally avoid the expression of an opinion regarding it. +Indeed, his own words leave us somewhat in doubt as to the +precise character of his notion regarding the zones. Perhaps we +shall do best to quote them: + +"Let the earth be supposed to consist of five zones. (1) The +equatorial circle described around it. (2) Another parallel to +this, and defining the frigid zone of the northern hemisphere. +(3) A circle passing through the poles and cutting the two +preceding circles at right- angles. The northern hemisphere +contains two quarters of the earth, which are bounded by the +equator and circle passing through the poles. Each of these +quarters should be supposed to contain a four-sided district, its +northern side being of one-half of the parallel next the pole, +its southern by the half of the equator, and its remaining sides +by two segments of the circle drawn through the poles, opposite +to each other, and equal in length. In one of these (which of +them is of no consequence) the earth which we inhabit is +situated, surrounded by a sea and similar to an island. This, as +we said before, is evident both to our senses and to our reason. +But let any one doubt this, it makes no difference so far as +geography is concerned whether you believe the portion of the +earth which we inhabit to be an island or only admit what we know +from experience --namely, that whether you start from the east or +the west you may sail all around it. Certain intermediate spaces +may have been left (unexplored), but these are as likely to be +occupied by sea as uninhabited land. The object of the geographer +is to describe known countries. Those which are unknown he passes +over equally with those beyond the limits of the inhabited earth. +It will, therefore, be sufficient for describing the contour of +the island we have been speaking of, if we join by a right line +the outmost points which, up to this time, have been explored by +voyagers along the coast on either side."[3] + +We may pass over the specific criticisms of Strabo upon various +explorations that seem to have been of great interest to his +contemporaries, including an alleged trip of one Eudoxus out into +the Atlantic, and the journeyings of Pytheas in the far north. It +is Pytheas, we may add, who was cited by Hipparchus as having +made the mistaken observation that the length of the shadow of +the gnomon is the same at Marseilles and Byzantium, hence that +these two places are on the same parallel. Modern commentators +have defended Pytheas as regards this observation, claiming that +it was Hipparchus and not Pytheas who made the second observation +from which the faulty induction was drawn. The point is of no +great significance, however, except as showing that a correct +method of determining the problems of latitude had thus early +been suggested. That faulty observations and faulty application +of the correct principle should have been made is not surprising. +Neither need we concern ourselves with the details as to the +geographical distances, which Strabo found so worthy of criticism +and controversy. But in leaving the great geographer we may +emphasize his point of view and that of his contemporaries by +quoting three fundamental principles which he reiterates as being +among the "facts established by natural philosophers." He tells +us that "(1) The earth and heavens are spheroidal. (2) The +tendency of all bodies having weight is towards a centre. (3) +Further, the earth being spheroidal and having the same centre as +the heavens, is motionless, as well as the axis that passes +through both it and the heavens. The heavens turn round both the +earth and its axis, from east to west. The fixed stars turn round +with it at the same rate as the whole. These fixed stars follow +in their course parallel circles, the principal of which are the +equator, two tropics, and the arctic circles; while the planets, +the sun, and the moon describe certain circles comprehended +within the zodiac."[4] + +Here, then, is a curious mingling of truth and error. The +Pythagorean doctrine that the earth is round had become a +commonplace, but it would appear that the theory of Aristarchus, +according to which the earth is in motion, has been almost +absolutely forgotten. Strabo does not so much as refer to it; +neither, as we shall see, is it treated with greater respect by +the other writers of the period. + + +TWO FAMOUS EXPOSITORS--PLINY AND PTOLEMY + +While Strabo was pursuing his geographical studies at Alexandria, +a young man came to Rome who was destined to make his name more +widely known in scientific annals than that of any other Latin +writer of antiquity. This man was Plinius Secundus, who, to +distinguish him from his nephew, a famous writer in another +field, is usually spoken of as Pliny the Elder. There is a famous +story to the effect that the great Roman historian Livy on one +occasion addressed a casual associate in the amphitheatre at +Rome, and on learning that the stranger hailed from the outlying +Spanish province of the empire, remarked to him, "Yet you have +doubtless heard of my writings even there." "Then," replied the +stranger, "you must be either Livy or Pliny." + +The anecdote illustrates the wide fame which the Roman naturalist +achieved in his own day. And the records of the Middle Ages show +that this popularity did not abate in succeeding times. Indeed, +the Natural History of Pliny is one of the comparatively few +bulky writings of antiquity that the efforts of copyists have +preserved to us almost entire. It is, indeed, a remarkable work +and eminently typical of its time; but its author was an +industrious compiler, not a creative genius. As a monument of +industry it has seldom been equalled, and in this regard it seems +the more remarkable inasmuch as Pliny was a practical man of +affairs who occupied most of his life as a soldier fighting the +battles of the empire. He compiled his book in the leisure hours +stolen from sleep, often writing by the light of the camp-fire. +Yet he cites or quotes from about four thousand works, most of +which are known to us only by his references. Doubtless Pliny +added much through his own observations. We know how keen was his +desire to investigate, since he lost his life through attempting +to approach the crater of Vesuvius on the occasion of that +memorable eruption which buried the cities of Herculaneum and +Pompeii. + +Doubtless the wandering life of the soldier had given Pliny +abundant opportunity for personal observation in his favorite +fields of botany and zoology. But the records of his own +observations are so intermingled with knowledge drawn from books +that it is difficult to distinguish the one from the other. Nor +does this greatly matter, for whether as closet-student or +field-naturalist, Pliny's trait of mind is essentially that of +the compiler. He was no philosophical thinker, no generalizer, no +path-maker in science. He lived at the close of a great +progressive epoch of thought; in one of those static periods when +numberless observers piled up an immense mass of details which +might advantageously be sorted into a kind of encyclopaedia. Such +an encyclopaedia is the so-called Natural History of Pliny. It is +a vast jumble of more or less uncritical statements regarding +almost every field of contemporary knowledge. The descriptions of +animals and plants predominate, but the work as a whole would +have been immensely improved had the compiler shown a more +critical spirit. As it is, he seems rather disposed to quote any +interesting citation that he comes across in his omnivorous +readings, shielding himself behind an equivocal "it is said," or +"so and so alleges." A single illustration will suffice to show +what manner of thing is thought worthy of repetition. + +"It is asserted," he says, "that if the fish called a sea-star is +smeared with the fox's blood and then nailed to the upper lintel +of the door, or to the door itself, with a copper nail, no +noxious spell will be able to obtain admittance, or, at all +events, be productive of any ill effects." + +It is easily comprehensible that a work fortified with such +practical details as this should have gained wide popularity. +Doubtless the natural histories of our own day would find readier +sale were they to pander to various superstitions not altogether +different from that here suggested. The man, for example, who +believes that to have a black cat cross his path is a lucky omen +would naturally find himself attracted by a book which took +account of this and similar important details of natural history. +Perhaps, therefore, it was its inclusion of absurdities, quite as +much as its legitimate value, that gave vogue to the celebrated +work of Pliny. But be that as it may, the most famous scientist +of Rome must be remembered as a popular writer rather than as an +experimental worker. In the history of the promulgation of +scientific knowledge his work is important; in the history of +scientific principles it may virtually be disregarded. + + +PTOLEMY, THE LAST GREAT ASTRONOMER OF ANTIQUITY + +Almost the same thing may be said of Ptolemy, an even more +celebrated writer, who was born not very long after the death of +Pliny. The exact dates of Ptolemy's life are not known, but his +recorded observations extend to the year 151 A.D. He was a +working astronomer, and he made at least one original discovery +of some significance--namely, the observation of a hitherto +unrecorded irregularity of the moon's motion, which came to be +spoken of as the moon's evection. This consists of periodical +aberrations from the moon's regular motion in its orbit, which, +as we now know, are due to the gravitation pull of the sun, but +which remained unexplained until the time of Newton. Ptolemy also +made original observations as to the motions of the planets. He +is, therefore, entitled to a respectable place as an observing +astronomer; but his chief fame rests on his writings. + +His great works have to do with geography and astronomy. In the +former field he makes an advance upon Strabo, citing the latitude +of no fewer than five thousand places. In the field of astronomy, +his great service was to have made known to the world the labors +of Hipparchus. Ptolemy has been accused of taking the star-chart +of his great predecessor without due credit, and indeed it seems +difficult to clear him of this charge. Yet it is at least open to +doubt whether be intended any impropriety, inasmuch as be all +along is sedulous in his references to his predecessor. Indeed, +his work might almost be called an exposition of the astronomical +doctrines of Hipparchus. No one pretends that Ptolemy is to be +compared with the Rhodesian observer as an original investigator, +but as a popular expounder his superiority is evidenced in the +fact that the writings of Ptolemy became practically the sole +astronomical text-book of the Middle Ages both in the East and in +the West, while the writings of Hipparchus were allowed to +perish. + +The most noted of all the writings of Ptolemy is the work which +became famous under the Arabic name of Almagest. This word is +curiously derived from the Greek title <gr h megisth suntazis>, +"the greatest construction," a name given the book to distinguish +it from a work on astrology in four books by the same author. For +convenience of reference it came to be spoken of merely as <gr h +megisth>, from which the Arabs form the title Tabair al Magisthi, +under which title the book was published in the year 827. From +this it derived the word Almagest, by which Ptolemy's work +continued to be known among the Arabs, and subsequently among +Europeans when the book again became known in the West. Ptolemy's +book, as has been said, is virtually an elaboration of the +doctrines of Hipparchus. It assumes that the earth is the fixed +centre of the solar system, and that the stars and planets +revolve about it in twenty-four hours, the earth being, of +course, spherical. It was not to be expected that Ptolemy should +have adopted the heliocentric idea of Aristarchus. Yet it is much +to be regretted that he failed to do so, since the deference +which was accorded his authority throughout the Middle Ages would +doubtless have been extended in some measure at least to this +theory as well, had he championed it. Contrariwise, his +unqualified acceptance of the geocentric doctrine sufficed to +place that doctrine beyond the range of challenge. + +The Almagest treats of all manner of astronomical problems, but +the feature of it which gained it widest celebrity was perhaps +that which has to do with eccentrics and epicycles. This theory +was, of course, but an elaboration of the ideas of Hipparchus; +but, owing to the celebrity of the expositor, it has come to be +spoken of as the theory of Ptolemy. We have sufficiently detailed +the theory in speaking of Hipparchus. It should be explained, +however, that, with both Hipparchus and Ptolemy, the theory of +epicycles would appear to have been held rather as a working +hypothesis than as a certainty, so far as the actuality of the +minor spheres or epicycles is concerned. That is to say, these +astronomers probably did not conceive either the epicycles or the +greater spheres as constituting actual solid substances. +Subsequent generations, however, put this interpretation upon the +theory, conceiving the various spheres as actual crystalline +bodies. It is difficult to imagine just how the various epicycles +were supposed to revolve without interfering with the major +spheres, but perhaps this is no greater difficulty than is +presented by the alleged properties of the ether, which +physicists of to-day accept as at least a working hypothesis. We +shall see later on how firmly the conception of concentric +crystalline spheres was held to, and that no real challenge was +ever given that theory until the discovery was made that comets +have an orbit that must necessarily intersect the spheres of the +various planets. + +Ptolemy's system of geography in eight books, founded on that of +Marinus of Tyre, was scarcely less celebrated throughout the +Middle Ages than the Almagest. It contained little, however, that +need concern us here, being rather an elaboration of the +doctrines to which we have already sufficiently referred. None of +Ptolemy's original manuscripts has come down to us, but there is +an alleged fifth-century manuscript attributed to Agathadamon of +Alexandria which has peculiar interest because it contains a +series of twenty-seven elaborately colored maps that are supposed +to be derived from maps drawn up by Ptolemy himself. In these +maps the sea is colored green, the mountains red or dark yellow, +and the land white. Ptolemy assumed that a degree at the equator +was 500 stadia instead of 604 stadia in length. We are not +informed as to the grounds on which this assumption was made, but +it has been suggested that the error was at least partially +instrumental in leading to one very curious result. "Taking the +parallel of Rhodes," says Donaldson,[5] "he calculated the +longitudes from the Fortunate Islands to Cattigara or the west +coast of Borneo at 180 degrees, conceiving this to be one-half +the circumference of the globe. The real distance is only 125 +degrees or 127 degrees, so that his measurement is wrong by one +third of the whole, one-sixth for the error in the measurement of +a degree and one-sixth for the errors in measuring the distance +geometrically. These errors, owing to the authority attributed to +the geography of Ptolemy in the Middle Ages, produced a +consequence of the greatest importance. They really led to the +discovery of America. For the design of Columbus to sail from the +west of Europe to the east of Asia was founded on the supposition +that the distance was less by one third than it really was." This +view is perhaps a trifle fanciful, since there is nothing to +suggest that the courage of Columbus would have balked at the +greater distance, and since the protests of the sailors, which +nearly thwarted his efforts, were made long before the distance +as estimated by Ptolemy had been covered; nevertheless it is +interesting to recall that the great geographical doctrines, upon +which Columbus must chiefly have based his arguments, had been +before the world in an authoritative form practically unheeded +for more than twelve hundred years, awaiting a champion with +courage enough to put them to the test. + + +GALEN--THE LAST GREAT ALEXANDRIAN + +There is one other field of scientific investigation to which we +must give brief attention before leaving the antique world. This +is the field of physiology and medicine. In considering it we +shall have to do with the very last great scientist of the +Alexandrian school. This was Claudius Galenus, commonly known as +Galen, a man whose fame was destined to eclipse that of all other +physicians of antiquity except Hippocrates, and whose doctrines +were to have the same force in their field throughout the Middle +Ages that the doctrines of Aristotle had for physical science. +But before we take up Galen's specific labors, it will be well to +inquire briefly as to the state of medical art and science in the +Roman world at the time when the last great physician of +antiquity came upon the scene. + +The Romans, it would appear, had done little in the way of +scientific discoveries in the field of medicine, but, +nevertheless, with their practicality of mind, they had turned to +better account many more of the scientific discoveries of the +Greeks than did the discoverers themselves. The practising +physicians in early Rome were mostly men of Greek origin, who +came to the capital after the overthrow of the Greeks by the +Romans. Many of them were slaves, as earning money by either +bodily or mental labor was considered beneath the dignity of a +Roman citizen. The wealthy Romans, who owned large estates and +numerous slaves, were in the habit of purchasing some of these +slave doctors, and thus saving medical fees by having them attend +to the health of their families. + +By the beginning of the Christian era medicine as a profession +had sadly degenerated, and in place of a class of physicians who +practised medicine along rational or legitimate lines, in the +footsteps of the great Hippocrates, there appeared great numbers +of "specialists," most of them charlatans, who pretended to +possess supernatural insight in the methods of treating certain +forms of disease. These physicians rightly earned the contempt of +the better class of Romans, and were made the object of many +attacks by the satirists of the time. Such specialists travelled +about from place to place in much the same manner as the +itinerant "Indian doctors" and "lightning tooth-extractors" do +to-day. Eye-doctors seem to have been particularly numerous, and +these were divided into two classes, eye-surgeons and eye-doctors +proper. The eye-surgeon performed such operations as cauterizing +for ingrowing eyelashes and operating upon growths about the +eyes; while the eye-doctors depended entirely upon salves and +lotions. These eye-salves were frequently stamped with the seal +of the physician who compounded them, something like two hundred +of these seals being still in existence. There were besides these +quacks, however, reputable eye-doctors who must have possessed +considerable skill in the treatment of certain ophthalmias. Among +some Roman surgical instruments discovered at Rheims were found +also some drugs employed by ophthalmic surgeons, and an analysis +of these show that they contained, among other ingredients, some +that are still employed in the treatment of certain affections of +the eye. + +One of the first steps taken in recognition of the services of +physicians was by Julius Caesar, who granted citizenship to all +physicians practising in Rome. This was about fifty years before +the Christian era, and from that time on there was a gradual +improvement in the attitude of the Romans towards the members of +the medical profession. As the Romans degenerated from a race of +sturdy warriors and became more and more depraved physically, the +necessity for physicians made itself more evident. Court +physicians, and physicians-in-ordinary, were created by the +emperors, as were also city and district physicians. In the year +133 A.D. Hadrian granted immunity from taxes and military service +to physicians in recognition of their public services. + +The city and district physicians, known as the archiatri +populaires, treated and cared for the poor without remuneration, +having a position and salary fixed by law and paid them +semi-annually. These were honorable positions, and the archiatri +were obliged to give instruction in medicine, without pay, to the +poor students. They were allowed to receive fees and donations +from their patients, but not, however, until the danger from the +malady was past. Special laws were enacted to protect them, and +any person subjecting them to an insult was liable to a fine "not +exceeding one thousand pounds." + +An example of Roman practicality is shown in the method of +treating hemorrhage, as described by Aulus Cornelius Celsus (53 +B.C. to 7 A.D.). Hippocrates and Hippocratic writers treated +hemorrhage by application of cold, pressure, styptics, and +sometimes by actual cauterizing; but they knew nothing of the +simple method of stopping a hemorrhage by a ligature tied around +the bleeding vessel. Celsus not only recommended tying the end of +the injured vessel, but describes the method of applying two +ligatures before the artery is divided by the surgeon--a common +practice among surgeons at the present time. The cut is made +between these two, and thus hemorrhage is avoided from either end +of the divided vessel. + +Another Roman surgeon, Heliodorus, not only describes the use of +the ligature in stopping hemorrhage, but also the practice of +torsion--twisting smaller vessels, which causes their lining +membrane to contract in a manner that produces coagulation and +stops hemorrhage. It is remarkable that so simple and practical a +method as the use of the ligature in stopping hemorrhage could +have gone out of use, once it had been discovered; but during the +Middle Ages it was almost entirely lost sight of, and was not +reintroduced until the time of Ambroise Pare, in the sixteenth +century. + +Even at a very early period the Romans recognized the advantage +of surgical methods on the field of battle. Each soldier was +supplied with bandages, and was probably instructed in applying +them, something in the same manner as is done now in all modern +armies. The Romans also made use of military hospitals and had +established a rude but very practical field-ambulance service. +"In every troop or bandon of two or four hundred men, eight or +ten stout fellows were deputed to ride immediately behind the +fighting-line to pick up and rescue the wounded, for which +purpose their saddles had two stirrups on the left side, while +they themselves were provided with water-flasks, and perhaps +applied temporary bandages. They were encouraged by a reward of a +piece of gold for each man they rescued. 'Noscomi' were male +nurses attached to the military hospitals, but not inscribed 'on +strength' of the legions, and were probably for the most part of +the servile class."[6] + +From the time of the early Alexandrians, Herophilus and +Erasistratus, whose work we have already examined, there had been +various anatomists of some importance in the Alexandrian school, +though none quite equal to these earlier workers. The best-known +names are those of Celsus (of whom we have already spoken), who +continued the work of anatomical investigation, and Marinus, who +lived during the reign of Nero, and Rufus of Ephesus. Probably +all of these would have been better remembered by succeeding +generations had their efforts not been eclipsed by those of +Galen. This greatest of ancient anatomists was born at Pergamus +of Greek parents. His father, Nicon, was an architect and a man +of considerable ability. Until his fifteenth year the youthful +Galen was instructed at home, chiefly by his father; but after +that time he was placed under suitable teachers for instruction +in the philosophical systems in vogue at that period. Shortly +after this, however, the superstitious Nicon, following the +interpretations of a dream, decided that his son should take up +the study of medicine, and placed him under the instruction of +several learned physicians. + +Galen was a tireless worker, making long tours into Asia Minor +and Palestine to improve himself in pharmacology, and studying +anatomy for some time at Alexandria. He appears to have been full +of the superstitions of the age, however, and early in his career +made an extended tour into western Asia in search of the +chimerical "jet-stone"--a stone possessing the peculiar qualities +of "burning with a bituminous odor and supposed to possess great +potency in curing such diseases as epilepsy, hysteria, and gout." + +By the time he had reached his twenty-eighth year he had +perfected his education in medicine and returned to his home in +Pergamus. Even at that time he had acquired considerable fame as +a surgeon, and his fellow-citizens showed their confidence in his +ability by choosing him as surgeon to the wounded gladiators +shortly after his return to his native city. In these duties his +knowledge of anatomy aided him greatly, and he is said to have +healed certain kinds of wounds that had previously baffled the +surgeons. + +In the time of Galen dissections of the human body were forbidden +by law, and he was obliged to confine himself to dissections of +the lower animals. He had the advantage, however, of the +anatomical works of Herophilus and Erasistratus, and he must have +depended upon them in perfecting his comparison between the +anatomy of men and the lower animals. It is possible that he did +make human dissections surreptitiously, but of this we have no +proof. + +He was familiar with the complicated structure of the bones of +the cranium. He described the vertebrae clearly, divided them +into groups, and named them after the manner of anatomists of +to-day. He was less accurate in his description of the muscles, +although a large number of these were described by him. Like all +anatomists before the time of Harvey, he had a very erroneous +conception of the circulation, although he understood that the +heart was an organ for the propulsion of blood, and he showed +that the arteries of the living animals did not contain air +alone, as was taught by many anatomists. He knew, also, that the +heart was made up of layers of fibres that ran in certain fixed +directions--that is, longitudinal, transverse, and oblique; but +he did not recognize the heart as a muscular organ. In proof of +this he pointed out that all muscles require rest, and as the +heart did not rest it could not be composed of muscular tissue. + +Many of his physiological experiments were conducted upon +scientific principles. Thus he proved that certain muscles were +under the control of definite sets of nerves by cutting these +nerves in living animals, and observing that the muscles supplied +by them were rendered useless. He pointed out also that nerves +have no power in themselves, but merely conduct impulses to and +from the brain and spinal-cord. He turned this peculiar knowledge +to account in the case of a celebrated sophist, Pausanias, who +had been under the treatment of various physicians for a numbness +in the fourth and fifth fingers of his left hand. These +physicians had been treating this condition by applications of +poultices to the hand itself. Galen, being called in +consultation, pointed out that the injury was probably not in the +hand itself, but in the ulner nerve, which controls sensation in +the fourth and fifth fingers. Surmising that the nerve must have +been injured in some way, he made careful inquiries of the +patient, who recalled that he had been thrown from his chariot +some time before, striking and injuring his back. Acting upon +this information, Galen applied stimulating remedies to the +source of the nerve itself--that is, to the bundle of +nerve-trunks known as the brachial plexus, in the shoulder. To +the surprise and confusion of his fellow-physicians, this method +of treatment proved effective and the patient recovered +completely in a short time. + +Although the functions of the organs in the chest were not well +understood by Galen, he was well acquainted with their anatomy. +He knew that the lungs were covered by thin membrane, and that +the heart was surrounded by a sac of very similar tissue. He made +constant comparisons also between these organs in different +animals, as his dissections were performed upon beasts ranging in +size from a mouse to an elephant. The minuteness of his +observations is shown by the fact that he had noted and described +the ring of bone found in the hearts of certain animals, such as +the horse, although not found in the human heart or in most +animals. + +His description of the abdominal organs was in general accurate. +He had noted that the abdominal cavity was lined with a peculiar +saclike membrane, the peritoneum, which also surrounded most of +the organs contained in the cavity, and he made special note that +this membrane also enveloped the liver in a peculiar manner. The +exactness of the last observation seems the more wonderful when +we reflect that even to-day the medical, student finds a correct +understanding of the position of the folds of the peritoneum one +of the most difficult subjects in anatomy. + +As a practical physician he was held in the highest esteem by the +Romans. The Emperor Marcus Aurelius called him to Rome and +appointed him physician-inordinary to his son Commodus, and on +special occasions Marcus Aurelius himself called in Galen as his +medical adviser. On one occasion, the three army surgeons in +attendance upon the emperor declared that he was about to be +attacked by a fever. Galen relates how "on special command I felt +his pulse, and finding it quite normal, considering his age and +the time of day, I declared it was no fever but a digestive +disorder, due to the food he had eaten, which must be converted +into phlegm before being excreted. Then the emperor repeated +three times, 'That's the very thing,' and asked what was to be +done. I answered that I usually gave a glass of wine with pepper +sprinkled on it, but for you kings we only use the safest +remedies, and it will suffice to apply wool soaked in hot nard +ointment locally. The emperor ordered the wool, wine, etc., to be +brought, and I left the room. His feet were warmed by rubbing +with hot hands, and after drinking the peppered wine, he said to +Pitholaus (his son's tutor), 'We have only one doctor, and that +an honest one,' and went on to describe me as the first of +physicians and the only philosopher, for he had tried many before +who were not only lovers of money, but also contentious, +ambitious, envious, and malignant."[7] + +It will be seen from this that Galen had a full appreciation of +his own abilities as a physician, but inasmuch as succeeding +generations for a thousand years concurred in the alleged +statement made by Marcus Aurelius as to his ability, he is +perhaps excusable for his open avowal of his belief in his +powers. His faith in his accuracy in diagnosis and prognosis was +shown when a colleague once said to him, "I have used the +prognostics of Hippocrates as well as you. Why can I not +prognosticate as well as you?" To this Galen replied, "By God's +help I have never been deceived in my prognosis."[8] It is +probable that this statement was made in the heat of argument, +and it is hardly to be supposed that he meant it literally. + +His systems of treatment were far in advance of his theories +regarding the functions of organs, causes of disease, etc., and +some of them are still first principles with physicians. Like +Hippocrates, he laid great stress on correct diet, exercise, and +reliance upon nature. "Nature is the overseer by whom health is +supplied to the sick," he says. "Nature lends her aid on all +sides, she decides and cures diseases. No one can be saved unless +nature conquers the disease, and no one dies unless nature +succumbs." + +From the picture thus drawn of Galen as an anatomist and +physician, one might infer that he should rank very high as a +scientific exponent of medicine, even in comparison with modern +physicians. There is, however, another side to the picture. His +knowledge of anatomy was certainly very considerable, but many of +his deductions and theories as to the functions of organs, the +cause of diseases, and his methods of treating them, would be +recognized as absurd by a modern school-boy of average +intelligence. His greatness must be judged in comparison with +ancient, not with modern, scientists. He maintained, for example, +that respiration and the pulse-beat were for one and the same +purpose--that of the reception of air into the arteries of the +body. To him the act of breathing was for the purpose of +admitting air into the lungs, whence it found its way into the +heart, and from there was distributed throughout the body by +means of the arteries. The skin also played an important part in +supplying the body with air, the pores absorbing the air and +distributing it through the arteries. But, as we know that he was +aware of the fact that the arteries also contained blood, he must +have believed that these vessels contained a mixture of the two. + +Modern anatomists know that the heart is divided into two +approximately equal parts by an impermeable septum of tough +fibres. Yet, Galen, who dissected the hearts of a vast number of +the lower animals according to his own account, maintained that +this septum was permeable, and that the air, entering one side of +the heart from the lungs, passed through it into the opposite +side and was then transferred to the arteries. + +He was equally at fault, although perhaps more excusably so, in +his explanation of the action of the nerves. He had rightly +pointed out that nerves were merely connections between the brain +and spinal-cord and distant muscles and organs, and had +recognized that there were two kinds of nerves, but his +explanation of the action of these nerves was that "nervous +spirits" were carried to the cavities of the brain by +blood-vessels, and from there transmitted through the body along +the nerve-trunks. + +In the human skull, overlying the nasal cavity, there are two +thin plates of bone perforated with numerous small apertures. +These apertures allow the passage of numerous nerve-filaments +which extend from a group of cells in the brain to the delicate +membranes in the nasal cavity. These perforations in the bone, +therefore, are simply to allow the passage of the nerves. But +Galen gave a very different explanation. He believed that impure +"animal spirits" were carried to the cavities of the brain by the +arteries in the neck and from there were sifted out through these +perforated bones, and so expelled from the body. + +He had observed that the skin played an important part in cooling +the body, but he seems to have believed that the heart was +equally active in overheating it. The skin, therefore, absorbed +air for the purpose of "cooling the heart," and this cooling +process was aided by the brain, whose secretions aided also in +the cooling process. The heart itself was the seat of courage; +the brain the seat of the rational soul; and the liver the seat +of love. + +The greatness of Galen's teachings lay in his knowledge of +anatomy of the organs; his weakness was in his interpretations of +their functions. Unfortunately, succeeding generations of +physicians for something like a thousand years rejected the +former but clung to the latter, so that the advances he had made +were completely overshadowed by the mistakes of his teachings. + + + +XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +It is a favorite tenet of the modern historian that history is a +continuous stream. The contention has fullest warrant. Sharp +lines of demarcation are an evidence of man's analytical +propensity rather than the work of nature. Nevertheless it would +be absurd to deny that the stream of history presents an +ever-varying current. There are times when it seems to rush +rapidly on; times when it spreads out into a broad--seemingly +static--current; times when its catastrophic changes remind us of +nothing but a gigantic cataract. Rapids and whirlpools, broad +estuaries and tumultuous cataracts are indeed part of the same +stream, but they are parts that vary one from another in their +salient features in such a way as to force the mind to classify +them as things apart and give them individual names. + +So it is with the stream of history; however strongly we insist +on its continuity we are none the less forced to recognize its +periodicity. It may not be desirable to fix on specific dates as +turning-points to the extent that our predecessors were wont to +do. We may not, for example, be disposed to admit that the Roman +Empire came to any such cataclysmic finish as the year 476 A.D., +when cited in connection with the overthrow of the last Roman +Empire of the West, might seem to indicate. But, on the other +hand, no student of the period can fail to realize that a great +change came over the aspect of the historical stream towards the +close of the Roman epoch. + +The span from Thales to Galen has compassed about eight hundred +years--let us say thirty generations. Throughout this period +there is scarcely a generation that has not produced great +scientific thinkers--men who have put their mark upon the +progress of civilization; but we shall see, as we look forward +for a corresponding period, that the ensuing thirty generations +produced scarcely a single scientific thinker of the first rank. +Eight hundred years of intellectual activity --thirty generations +of greatness; then eight hundred years of stasis--thirty +generations of mediocrity; such seems to be the record as viewed +in perspective. Doubtless it seemed far different to the +contemporary observer; it is only in reasonable perspective that +any scene can be viewed fairly. But for us, looking back without +prejudice across the stage of years, it seems indisputable that a +great epoch came to a close at about the time when the barbarian +nations of Europe began to sweep down into Greece and Italy. We +are forced to feel that we have reached the limits of progress of +what historians are pleased to call the ancient world. For about +eight hundred years Greek thought has been dominant, but in the +ensuing period it is to play a quite subordinate part, except in +so far as it influences the thought of an alien race. As we leave +this classical epoch, then, we may well recapitulate in brief its +triumphs. A few words will suffice to summarize a story the +details of which have made up our recent chapters. + +In the field of cosmology, Greek genius has demonstrated that the +earth is spheroidal, that the moon is earthlike in structure and +much smaller than our globe, and that the sun is vastly larger +and many times more distant than the moon. The actual size of the +earth and the angle of its axis with the ecliptic have been +measured with approximate accuracy. It has been shown that the +sun and moon present inequalities of motion which may be +theoretically explained by supposing that the earth is not +situated precisely at the centre of their orbits. A system of +eccentrics and epicycles has been elaborated which serves to +explain the apparent motions of the heavenly bodies in a manner +that may be called scientific even though it is based, as we now +know, upon a false hypothesis. The true hypothesis, which places +the sun at the centre of the planetary system and postulates the +orbital and axial motions of our earth in explanation of the +motions of the heavenly bodies, has been put forward and ardently +championed, but, unfortunately, is not accepted by the dominant +thinkers at the close of our epoch. In this regard, therefore, a +vast revolutionary work remains for the thinkers of a later +period. Moreover, such observations as the precession of the +equinoxes and the moon's evection are as yet unexplained, and +measurements of the earth's size, and of the sun's size and +distance, are so crude and imperfect as to be in one case only an +approximation, and in the other an absurdly inadequate +suggestion. But with all these defects, the total achievement of +the Greek astronomers is stupendous. To have clearly grasped the +idea that the earth is round is in itself an achievement that +marks off the classical from the Oriental period as by a great +gulf. + +In the physical sciences we have seen at least the beginnings of +great things. Dynamics and hydrostatics may now, for the first +time, claim a place among the sciences. Geometry has been +perfected and trigonometry has made a sure beginning. The +conception that there are four elementary substances, earth, +water, air, and fire, may not appear a secure foundation for +chemistry, yet it marks at least an attempt in the right +direction. Similarly, the conception that all matter is made up +of indivisible particles and that these have adjusted themselves +and are perhaps held in place by a whirling motion, while it is +scarcely more than a scientific dream, is, after all, a dream of +marvellous insight. + +In the field of biological science progress has not been so +marked, yet the elaborate garnering of facts regarding anatomy, +physiology, and the zoological sciences is at least a valuable +preparation for the generalizations of a later time. + +If with a map before us we glance at the portion of the globe +which was known to the workers of the period now in question, +bearing in mind at the same time what we have learned as to the +seat of labors of the various great scientific thinkers from +Thales to Galen, we cannot fail to be struck with a rather +startling fact, intimations of which have been given from time to +time--the fact, namely, that most of the great Greek thinkers did +not live in Greece itself. As our eye falls upon Asia Minor and +its outlying islands, we reflect that here were born such men as +Thales, Anaximander, Anaximenes, Heraclitus, Pythagoras, +Anaxagoras, Socrates, Aristarchus, Hipparchus, Eudoxus, +Philolaus, and Galen. From the northern shores of the aegean came +Lucippus, Democritus, and Aristotle. Italy, off to the west, is +the home of Pythagoras and Xenophanes in their later years, and +of Parmenides and Empedocles, Zeno, and Archimedes. Northern +Africa can claim, by birth or by adoption, such names as Euclid, +Apollonius of Perga, Herophilus, Erasistratus, Aristippus, +Eratosthenes, Ctesibius, Hero, Strabo, and Ptolemy. This is but +running over the list of great men whose discoveries have claimed +our attention. Were we to extend the list to include a host of +workers of the second rank, we should but emphasize the same +fact. + +All along we are speaking of Greeks, or, as they call themselves, +Hellenes, and we mean by these words the people whose home was a +small jagged peninsula jutting into the Mediterranean at the +southeastern extremity of Europe. We think of this peninsula as +the home of Greek culture, yet of all the great thinkers we have +just named, not one was born on this peninsula, and perhaps not +one in five ever set foot upon it. In point of fact, one Greek +thinker of the very first rank, and one only, was born in Greece +proper; that one, however, was Plato, perhaps the greatest of +them all. With this one brilliant exception (and even he was born +of parents who came from the provinces), all the great thinkers +of Greece had their origin at the circumference rather than the +centre of the empire. And if we reflect that this circumference +of the Greek world was in the nature of the case the widely +circling region in which the Greek came in contact with other +nations, we shall see at once that there could be no more +striking illustration in all history than that furnished us here +of the value of racial mingling as a stimulus to intellectual +progress. + +But there is one other feature of the matter that must not be +overlooked. Racial mingling gives vitality, but to produce the +best effect the mingling must be that of races all of which are +at a relatively high plane of civilization. In Asia Minor the +Greek mingled with the Semite, who had the heritage of centuries +of culture; and in Italy with the Umbrians, Oscans, and +Etruscans, who, little as we know of their antecedents, have left +us monuments to testify to their high development. The chief +reason why the racial mingling of a later day did not avail at +once to give new life to Roman thought was that the races which +swept down from the north were barbarians. It was no more +possible that they should spring to the heights of classical +culture than it would, for example, be possible in two or three +generations to produce a racer from a stock of draught horses. +Evolution does not proceed by such vaults as this would imply. +Celt, Goth, Hun, and Slav must undergo progressive development +for many generations before the population of northern Europe can +catch step with the classical Greek and prepare to march forward. +That, perhaps, is one reason why we come to a period of stasis or +retrogression when the time of classical activity is over. But, +at best, it is only one reason of several. + +The influence of the barbarian nations will claim further +attention as we proceed. But now, for the moment, we must turn +our eyes in the other direction and give attention to certain +phases of Greek and of Oriental thought which were destined to +play a most important part in the development of the Western +mind--a more important part, indeed, in the early mediaeval +period than that played by those important inductions of science +which have chiefly claimed our attention in recent chapters. The +subject in question is the old familiar one of false inductions +or pseudoscience. In dealing with the early development of +thought and with Oriental science, we had occasion to emphasize +the fact that such false inductions led everywhere to the +prevalence of superstition. In dealing with Greek science, we +have largely ignored this subject, confining attention chiefly to +the progressive phases of thought; but it must not be inferred +from this that Greek science, with all its secure inductions, was +entirely free from superstition. On the contrary, the most casual +acquaintance with Greek literature would suffice to show the +incorrectness of such a supposition. True, the great thinkers of +Greece were probably freer from this thraldom. of false +inductions than any of their predecessors. Even at a very early +day such men as Xenophanes, Empedocles, Anaxagoras, and Plato +attained to a singularly rationalistic conception of the +universe. + +We saw that "the father of medicine," Hippocrates, banished +demonology and conceived disease as due to natural causes. At a +slightly later day the sophists challenged all knowledge, and +Pyrrhonism became a synonym for scepticism in recognition of the +leadership of a master doubter. The entire school of Alexandrians +must have been relatively free from superstition, else they could +not have reasoned with such effective logicality from their +observations of nature. It is almost inconceivable that men like +Euclid and Archimedes, and Aristarchus and Eratosthenes, and +Hipparchus and Hero, could have been the victims of such +illusions regarding occult forces of nature as were constantly +postulated by Oriental science. Herophilus and Erasistratus and +Galen would hardly have pursued their anatomical studies with +equanimity had they believed that ghostly apparitions watched +over living and dead alike, and exercised at will a malign +influence. + +Doubtless the Egyptian of the period considered the work, of the +Ptolemaic anatomists an unspeakable profanation, and, indeed, it +was nothing less than revolutionary--so revolutionary that it +could not be sustained in subsequent generations. We have seen +that the great Galen, at Rome, five centuries after the time of +Herophilus, was prohibited from dissecting the human subject. The +fact speaks volumes for the attitude of the Roman mind towards +science. Vast audiences made up of every stratum of society +thronged the amphitheatre, and watched exultingly while man slew +his fellow-man in single or in multiple combat. Shouts of +frenzied joy burst from a hundred thousand throats when the +death-stroke was given to a new victim. The bodies of the slain, +by scores, even by hundreds, were dragged ruthlessly from the +arena and hurled into a ditch as contemptuously as if pity were +yet unborn and human life the merest bauble. Yet the same eyes +that witnessed these scenes with ecstatic approval would have +been averted in pious horror had an anatomist dared to approach +one of the mutilated bodies with the scalpel of science. It was +sport to see the blade of the gladiator enter the quivering, +living flesh of his fellow-gladiator; it was joy to see the warm +blood spurt forth from the writhing victim while he still lived; +but it were sacrilegious to approach that body with the knife of +the anatomist, once it had ceased to pulsate with life. Life +itself was held utterly in contempt, but about the realm of death +hovered the threatening ghosts of superstition. And such, be it +understood, was the attitude of the Roman populace in the early +and the most brilliant epoch of the empire, before the Western +world came under the influence of that Oriental philosophy which +was presently to encompass it. + +In this regard the Alexandrian world was, as just intimated, far +more advanced than the Roman, yet even there we must suppose that +the leaders of thought were widely at variance with the popular +conceptions. A few illustrations, drawn from Greek literature at +various ages, will suggest the popular attitude. In the first +instance, consider the poems of Homer and of Hesiod. For these +writers, and doubtless for the vast majority of their readers, +not merely of their own but of many subsequent generations, the +world is peopled with a multitude of invisible apparitions, +which, under title of gods, are held to dominate the affairs of +man. It is sometimes difficult to discriminate as to where the +Greek imagination drew the line between fact and allegory; nor +need we attempt to analyse the early poetic narratives to this +end. It will better serve our present purpose to cite three or +four instances which illustrate the tangibility of beliefs based +upon pseudo-scientific inductions. + +Let us cite, for example, the account which Herodotus gives us of +the actions of the Greeks at Plataea, when their army confronted +the remnant of the army of Xerxes, in the year 479 B.C. Here we +see each side hesitating to attack the other, merely because the +oracle had declared that whichever side struck the first blow +would lose the conflict. Even after the Persian soldiers, who +seemingly were a jot less superstitious or a shade more impatient +than their opponents, had begun the attack, we are told that the +Greeks dared not respond at first, though they were falling +before the javelins of the enemy, because, forsooth, the entrails +of a fowl did not present an auspicious appearance. And these +were Greeks of the same generation with Empedocles and Anaxagoras +and aeschylus; of the same epoch with Pericles and Sophocles and +Euripides and Phidias. Such was the scientific status of the +average mind--nay, of the best minds--with here and there a rare +exception, in the golden age of Grecian culture. + +Were we to follow down the pages of Greek history, we should but +repeat the same story over and over. We should, for example, see +Alexander the Great balked at the banks of the Hyphasis, and +forced to turn back because of inauspicious auguries based as +before upon the dissection of a fowl. Alexander himself, to be +sure, would have scorned the augury; had he been the prey of such +petty superstitions he would never have conquered Asia. We know +how he compelled the oracle at Delphi to yield to his wishes; how +he cut the Gordian knot; how he made his dominating personality +felt at the temple of Ammon in Egypt. We know, in a word, that he +yielded to superstitions only in so far as they served his +purpose. Left to his own devices, he would not have consulted an +oracle at the banks of the Hyphasis; or, consulting, would have +forced from the oracle a favorable answer. But his subordinates +were mutinous and he had no choice. Suffice it for our present +purpose that the oracle was consulted, and that its answer turned +the conqueror back. + +One or two instances from Roman history may complete the picture. +Passing over all those mythical narratives which virtually +constitute the early history of Rome, as preserved to us by such +historians as Livy and Dionysius, we find so logical an historian +as Tacitus recording a miraculous achievement of Vespasian +without adverse comment. "During the months when Vespasian was +waiting at Alexandria for the periodical season of the summer +winds, and a safe navigation, many miracles occurred by which the +favor of Heaven and a sort of bias in the powers above towards +Vespasian were manifested." Tacitus then describes in detail the +cure of various maladies by the emperor, and relates that the +emperor on visiting a temple was met there, in the spirit, by a +prominent Egyptian who was proved to be at the same time some +eighty miles distant from Alexandria. + +It must be admitted that Tacitus, in relating that Vespasian +caused the blind to see and the lame to walk, qualifies his +narrative by asserting that "persons who are present attest the +truth of the transaction when there is nothing to be gained by +falsehood." Nor must we overlook the fact that a similar belief +in the power of royalty has persisted almost to our own day. But +no such savor of scepticism attaches to a narrative which Dion +Cassius gives us of an incident in the life of Marcus +Aurelius--an incident that has become famous as the episode of +The Thundering Legion. Xiphilinus has preserved the account of +Dion, adding certain picturesque interpretations of his own. The +original narrative, as cited, asserts that during one of the +northern campaigns of Marcus Aurelius, the emperor and his army +were surrounded by the hostile Quadi, who had every advantage of +position and who presently ceased hostilities in the hope that +heat and thirst would deliver their adversaries into their hands +without the trouble of further fighting. "Now," says Dion, "while +the Romans, unable either to combat or to retreat, and reduced to +the last extremity by wounds, fatigue, heat, and thirst, were +standing helplessly at their posts, clouds suddenly gathered in +great number and rain descended in floods--certainly not without +divine intervention, since the Egyptian Maege Arnulphis, who was +with Marcus Antoninus, is said to have invoked several genii by +the aerial mercury by enchantment, and thus through them had +brought down rain." + +Here, it will be observed, a supernatural explanation is given of +a natural phenomenon. But the narrator does not stop with this. +If we are to accept the account of Xiphilinus, Dion brings +forward some striking proofs of divine interference. Xiphilinus +gives these proofs in the following remarkable paragraph: + +"Dion adds that when the rain began to fall every soldier lifted +his head towards heaven to receive the water in his mouth; but +afterwards others hold out their shields or their helmets to +catch the water for themselves and for their horses. Being set +upon by the barbarians . . . while occupied in drinking, they +would have been seriously incommoded had not heavy hail and +numerous thunderbolts thrown consternation into the ranks of the +enemy. Fire and water were seen to mingle as they left the +heavens. The fire, however, did not reach the Romans, but if it +did by chance touch one of them it was immediately extinguished, +while at the same time the rain, instead of comforting the +barbarians, seemed merely to excite like oil the fire with which +they were being consumed. Some barbarians inflicted wounds upon +themselves as though their blood had power to extinguish flames, +while many rushed over to the side of the Romans, hoping that +there water might save them." + +We cannot better complete these illustrations of pagan credulity +than by adding the comment of Xiphilinus himself. That writer was +a Christian, living some generations later than Dion. He never +thought of questioning the facts, but he felt that Dion's +interpretation of these facts must not go unchallenged. As he +interprets the matter, it was no pagan magician that wrought the +miracle. He even inclines to the belief that Dion himself was +aware that Christian interference, and not that of an Egyptian, +saved the day. "Dion knew," he declares, "that there existed a +legion called The Thundering Legion, which name was given it for +no other reason than for what came to pass in this war," and that +this legion was composed of soldiers from Militene who were all +professed Christians. "During the battle," continues Xiphilinus, +"the chief of the Pretonians , had set at Marcus Antoninus, who +was in great perplexity at the turn events were taking, +representing to him that there was nothing the people called +Christians could not obtain by their prayers, and that among his +forces was a troop composed wholly of followers of that religion. +Rejoiced at this news, Marcus Antoninus demanded of these +soldiers that they should pray to their god, who granted their +petition on the instant, sent lightning among the enemy and +consoled the Romans with rain. Struck by this wonderful success, +the emperor honored the Christians in an edict and named their +legion The Thundering. It is even asserted that a letter existed +by Marcus Antoninus on this subject. The pagans well knew that +the company was called The Thunderers, having attested the fact +themselves, but they revealed nothing of the occasion on which +the leader received the name."[1] + +Peculiar interest attaches to this narrative as illustrating both +credulousness as to matters of fact and pseudo-scientific +explanation of alleged facts. The modern interpreter may suppose +that a violent thunderstorm came up during the course of a battle +between the Romans and the so-called barbarians, and that owing +to the local character of the storm, or a chance discharge of +lightning, the barbarians suffered more than their opponents. We +may well question whether the philosophical emperor himself put +any other interpretation than this upon the incident. But, on the +other hand, we need not doubt that the major part of his soldiers +would very readily accept such an explanation as that given by +Dion Cassius, just as most readers of a few centuries later would +accept the explanation of Xiphilinus. It is well to bear this +thought in mind in considering the static period of science upon +which we are entering. We shall perhaps best understand this +period, and its seeming retrogressions, if we suppose that the +average man of the Middle Ages was no more credulous, no more +superstitious, than the average Roman of an earlier period or +than the average Greek; though the precise complexion of his +credulity had changed under the influence of Oriental ideas, as +we have just seen illustrated by the narrative of Xiphilinus. + + + +APPENDIX + +REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES + + + +CHAPTER I. PREHISTORIC SCIENCE + +Length of the Prehistoric Period.--It is of course quite +impossible to reduce the prehistoric period to any definite +number of years. There are, however, numerous bits of evidence +that enable an anthropologist to make rough estimates as to the +relative lengths of the different periods into which prehistoric +time is divided. Gabriel de Mortillet, one of the most +industrious students of prehistoric archaeology, ventured to give +a tentative estimate as to the numbers of years involved in each +period. He of course claimed for this nothing more than the value +of a scientific guess. It is, however, a guess based on a very +careful study of all data at present available. Mortillet divides +the prehistoric period, as a whole, into four epochs. The first +of these is the preglacial, which he estimates as comprising +seventy-eight thousand years; the second is the glacial, covering +one hundred thousand years; then follows what he terms the +Solutreen, which numbers eleven thousand years; and, finally, the +Magdalenien, comprising thirty-three thousand years. This gives, +for the prehistoric period proper, a term of about two hundred +and twenty-two thousand years. Add to this perhaps twelve +thousand years ushering in the civilization of Egypt, and the six +thousand years of stable, sure chronology of the historical +period, and we have something like two hundred and thirty +thousand or two hundred and forty thousand years as the age of +man. + +"These figures," says Mortillet, "are certainly not exaggerated. +It is even probable that they are below the truth. Constantly new +discoveries are being made that tend to remove farther back the +date of man's appearance." We see, then, according to this +estimate, that about a quarter of a million years have elapsed +since man evolved to a state that could properly be called human. +This guess is as good as another, and it may advantageously be +kept in mind, as it will enable us all along to understand better +than we might otherwise be able to do the tremendous force of +certain prejudices and preconceptions which recent man inherited +from his prehistoric ancestor. Ideas which had passed current as +unquestioned truths for one hundred thousand years or so are not +easily cast aside. + +In going back, in imagination, to the beginning of the +prehistoric period, we must of course reflect, in accordance with +modern ideas on the subject, that there was no year, no +millennium even, when it could be said expressly: "This being was +hitherto a primate, he is now a man." The transition period must +have been enormously long, and the changes from generation to +generation, even from century to century, must have been very +slight. In speaking of the extent of the age of man this must be +borne in mind: it must be recalled that, even if the period were +not vague for other reasons, the vagueness of its beginning must +make it indeterminate. + +Bibliographical Notes.--A great mass of literature has been +produced in recent years dealing with various phases of the +history of prehistoric man. No single work known to the writer +deals comprehensively with the scientific attainments of early +man; indeed, the subject is usually ignored, except where +practical phases of the mechanical arts are in question. But of +course any attempt to consider the condition of primitive man +talies into account, by inference at least, his knowledge and +attainments. Therefore, most works on anthropology, ethnology, +and primitive culture may be expected to throw some light on our +present subject. Works dealing with the social and mental +conditions of existing savages are also of importance, since it +is now an accepted belief that the ancestors of civilized races +evolved along similar lines and passed through corresponding +stages of nascent culture. Herbert Spencer's Descriptive +Sociology presents an unequalled mass of facts regarding existing +primitive races, but, unfortunately, its inartistic method of +arrangement makes it repellent to the general reader. E. B. +Tyler's Primitive Culture and Anthropology; Lord Avebury's +Prehistoric Times, The Origin of Civilization, and The Primitive +Condition of Man; W. Boyd Dawkin's Cave-Hunting and Early Man in +Britain; and Edward Clodd's Childhood of the World and Story of +Primitive Man are deservedly popular. Paul Topinard's Elements +d'Anthropologie Generale is one of the best-known and most +comprehensive French works on the technical phases of +anthropology; but Mortillet's Le Prehistorique has a more popular +interest, owing to its chapters on primitive industries, though +this work also contains much that is rather technical. Among +periodicals, the Revue de l'Ecole d'Anthropologie de Paris, +published by the professors, treats of all phases of +anthropology, and the American Anthropologist, edited by F. W. +Hodge for the American Anthropological Association, and intended +as "a medium of communication between students of all branches of +anthropology," contains much that is of interest from the present +stand-point. The last-named journal devotes a good deal of space +to Indian languages. + + +CHAPTER II. EGYPTIAN SCIENCE + +1 (p. 34). Sir J. Norman Lockyer, The Dawn of Astronomy; a study +of the temple worship and mythology of the ancient Egyptians, +London, 1894. + +2 (p. 43). G. Maspero, Histoire Ancie-nne des Peuples de l'Orient +Classique, Paris, 1895. Translated as (1) The Dawn of +Civilization, (2) The Struggle of the Nations, (3) The Passing of +the Empires, 3 vols., London and New York, 1894-1900. Professor +Maspero is one of the most famous of living Orientalists. His +most important special studies have to do with Egyptology, but +his writings cover the entire field of Oriental antiquity. He is +a notable stylist, and his works are at once readable and +authoritative. + +3 (p. 44). Adolf Erman, Life in Ancient Egypt, London, 1894, p. +352. (Translated from the original German work entitled Aegypten +und aegyptisches Leben in Alterthum, Tilbigen, 1887.) An +altogether admirable work, full of interest for the general +reader, though based on the most erudite studies. + +4 (p. 47). Erman, op. cit., pp. 356, 357. + +5 (p. 48). Erman, op. cit., p. 357. The work on Egyptian medicine +here referred to is Georg Ebers' edition of an Egyptian document +discovered by the explorer whose name it bears. It remains the +most important source of our knowledge of Egyptian medicine. As +mentioned in the text, this document dates from the eighteenth +dynasty--that is to say, from about the fifteenth or sixteenth +century, B.C., a relatively late period of Egyptian history. + +6 (p. 49). Erman, op. cit., p. 357. + +7 (p. 50). The History of Herodotus, pp. 85-90. There are +numerous translations of the famous work of the "father of +history," one of the most recent and authoritative being that of +G. C. Macaulay, M.A., in two volumes, Macmillan & Co., London and +New York, 1890. + +8 (p. 50). The Historical Library of Diodorus the Sicilian, +London, 1700. This most famous of ancient world histories is +difficult to obtain in an English version. The most recently +published translation known to the writer is that of G. Booth, +London, 1814. + +9 (p. 51). Erman, op. cit., p. 357. + +10 (p. 52). The Papyrus Rhind is a sort of mathematical hand-book +of the ancient Egyptians; it was made in the time of the Hyksos +Kings (about 2000 B.C.), but is a copy of an older book. It is +now preserved in the British Museum. + +The most accessible recent sources of information as to the +social conditions of the ancient Egyptians are the works of +Maspero and Erman, above mentioned; and the various publications +of W. M. Flinders Petrie, The Pyramids and Temples of Gizeh, +London, 1883; Tanis I., London, 1885; Tanis H., Nebesheh, and +Defe-nnel, London, 1887; Ten Years' Diggings, London, 1892; Syria +and Egypt from the Tel-el-Amar-na Letters, London, 1898, etc. The +various works of Professor Petrie, recording his explorations +from year to year, give the fullest available insight into +Egyptian archaeology. + +CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + +1 (p. 57). The Medes. Some difference of opinion exists among +historians as to the exact ethnic relations of the conquerors; +the precise date of the fall of Nineveh is also in doubt. + +2 (p. 57). Darius. The familiar Hebrew narrative ascribes the +first Persian conquest of Babylon to Darius, but inscriptions of +Cyrus and of Nabonidus, the Babylonian king, make it certain that +Cyrus was the real conqueror. These inscriptions are preserved on +cylinders of baked clay, of the type made familiar by the +excavation of the past fifty years, and they are invaluable +historical documents. + +3 (p. 58). Berosus. The fragments of Berosus have been translated +by L. P. Cory, and included in his Ancient Fragments of +Phenician, Chaldean, Egyptian, and Other Writers, London, 1826, +second edition, 1832. + +4 (p. 58). Chaldean learning. Recent writers reserve the name +Chaldean for the later period of Babylonian history-- the time +when the Greeks came in contact with the Mesopotamians--in +contradistinction to the earlier periods which are revealed to us +by the archaeological records. + +5 (p. 59) King Sargon of Agade. The date given for this early +king must not be accepted as absolute; but it is probably +approximately correct. + +6 (p. 59). Nippur. See the account of the early expeditions as +recorded by the director, Dr. John P. Peters, Nippur, or +explorations and adventures, etc., New York and London, 1897. + +7 (p. 62). Fritz Hommel, Geschichte Babyloniens und Assyriens, +Berlin, 1885. + +8 (p. 63). R. Campbell Thompson, Reports of the Magicians and +Astrologers of Nineveh and Babylon, London, 1900, p. xix. + +9 (p. 64). George Smith, The Assyrian Canon, p. 21. + +10 (p. 64). Thompson, op. cit., p. xix. + +11 (p. 65). Thompson, op. cit., p. 2. + +12 (p. 67). Thompson, op. cit., p. xvi. + +13 (p. 68). Sextus Empiricus, author of Adversus Mathematicos, +lived about 200 A.D. + +14 (p. 68). R. Campbell Thompson, op. cit., p. xxiv. + +15 (p. 72). Records of the Past (editor, Samuel Birch), Vol. +III., p. 139. + +16 (p. 72). Ibid., Vol. V., p. 16. + +17 (p. 72). Quoted in Records of the Past, Vol. III., p. 143, +from the Translations of the Society of Biblical Archeology, vol. +II., p. 58. + +18 (p. 73). Records of the Past, vol. L, p. 131. + +19 (p. 73). Ibid., vol. V., p. 171. + +20 (p. 74). Ibid., vol. V., p. 169. + +21 (p. 74). Joachim Menant, La Bibliotheque du Palais de Ninive, +Paris, 188o. + +22 (p. 76). Code of Khamurabi. This famous inscription is on a +block of black diorite nearly eight feet in height. It was +discovered at Susa by the French expedition under M. de Morgan, +in December, 1902. We quote the translation given in The +Historians' History of the World, edited by Henry Smith Williams, +London and New York, 1904, Vol. I, p. 510. + +23 (p. 77). The Historical Library of Diodorus Siculus, p. 519. + +24 (p. 82). George S. Goodspeed, Ph.D., History of the +Babylonians and Assyrians, New York, 1902. + +25 (p. 82). George Rawlinson, Great Oriental Monarchies, (second +edition, London, 1871), Vol. III., pp. 75 ff. + +Of the books mentioned above, that of Hommel is particularly full +in reference to culture development; Goodspeed's small volume +gives an excellent condensed account; the original documents as +translated in the various volumes of Records of the Past are full +of interest; and Menant's little book is altogether admirable. +The work of excavation is still going on in old Babylonia, and +newly discovered texts add from time to time to our knowledge, +but A. H. Layard's Nineveh and its Remains (London, 1849) still +has importance as a record of the most important early +discoveries. The general histories of Antiquity of Duncker, +Lenormant, Maspero, and Meyer give full treatment of Babylonian +and Assyrian development. Special histories of Babylonia and +Assyria, in addition to these named above, are Tiele's +Babylonisch-Assyrische Geschichte (Zwei Tiele, Gotha, 1886-1888); +Winckler's Geschichte Babyloniens und Assyriens (Berlin, +1885-1888), and Rogers' History of Babylonia and Assyria, New +York and London, 1900, the last of which, however, deals almost +exclusively with political history. Certain phases of science, +particularly with reference to chronology and cosmology, are +treated by Edward Meyer (Geschichte des Alterthum, Vol. I., +Stuttgart, 1884), and by P. Jensen (Die Kosmologie der +Babylonier, Strassburg, 1890), but no comprehensive specific +treatment of the subject in its entirety has yet been attempted. + +CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + +1 (p. 87). Vicomte E. de Rouge, Memoire sur l'Origine Egyptienne +de l'Alphabet Phinicien, Paris, 1874. + +2 (p. 88). See the various publications of Mr. Arthur Evans. + +3 (p. 80). Aztec and Maya writing. These pictographs are still in +the main undecipherable, and opinions differ as to the exact +stage of development which they represent. + +4 (p. 90). E. A. Wallace Budge's First Steps in Egyptian, London, +1895, is an excellent elementary work on the Egyptian writing. +Professor Erman's Egyptian Grammar, London, 1894, is the work of +perhaps the foremost living Egyptologist. + +5 (P. 93). Extant examples of Babylonian and Assyrian writing +give opportunity to compare earlier and later systems, so the +fact of evolution from the pictorial to the phonetic system rests +on something more than mere theory. + +6 (p. 96). Friedrich Delitzsch, Assyrischc Lesestucke mit +grammatischen Tabellen und vollstdndigem Glossar einfiihrung in +die assyrische und babylonische Keilschrift-litteratur bis hinauf +zu Hammurabi, Leipzig, 1900. + +7 (p. 97). It does not appear that the Babylonians thcmselves +ever gave up the old system of writing, so long as they retained +political autonomy. + +8 (p. 101). See Isaac Taylor's History of the Alphabet; an +Account of the origin and Development of Letters, new edition, 2 +vols., London, 1899. + +For facsimiles of the various scripts, see Henry Smith Williams' +History of the Art Of Writing, 4 vols, New York and London, +1902-1903. + +CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + +1 (p. III). Anaximander, as recorded by Plutarch, vol. VIII-. See +Arthur Fairbanks'First Philosophers of Greece: an Edition and +Translation of the Remaining Fragments of the Pre-Socratic +Philosophers, together with a Translation of the more Important +Accounts of their Opinions Contained in the Early Epitomcs of +their Works, London, 1898. This highly scholarly and extremely +useful book contains the Greek text as well as translations. + +CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +1 (p. 117). George Henry Lewes, A Biographical History of +Philosophy from its Origin in Greece down to the Present Day, +enlarged edition, New York, 1888, p. 17. + +2 (p. 121). Diogenes Laertius, The Lives and Opinions of Eminent +Philosophers, C. D. Yonge's translation, London, 1853, VIII., p. +153. + +3 (p. 121). Alexander, Successions of Philosophers. + +4 (p. 122). "All over its centre." Presumably this is intended to +refer to the entire equatorial region. + +5 (p. 125). Laertius, op. cit., pp. 348-351. + +6 (p. 128). Arthur Fairbanks, The First Philosophers of Greece +London, 1898, pp. 67-717. + +7 (p. 129). Ibid., p. 838. + +8 (p. 130). Ibid., p. 109. + +9 (p. 130). Heinrich Ritter, The History of Ancient Philosophy, +translated from the German by A. J. W. Morrison, 4 vols., London, +1838, vol, I., p. 463. + +10 (p. 131). Ibid., p. 465. + +11 (p. 132). George Henry Lewes, op. cit., p. 81. + +12 (p. 135). Fairbanks, op. cit., p. 201. + +13 (p. 136). Ibid., P. 234. + +14 (p. 137). Ibid., p. 189. + +15 (p. 137). Ibid., P. 220. + +16 (p. 138). Ibid., p. 189. + +17 (p. 138). Ibid., p. 191. + +CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +1 (p. 150). Theodor Gomperz, Greek Thinkers: a History of Ancient +Philosophy (translated from the German by Laurie Magnes), New +York, 190 1, pp. 220, 221. + +2 (p. 153). Aristotle's Treatise on Respiration, ch. ii. + +3 (p. 159). Fairbanks' translation of the fragments of +Anaxagoras, in The First Philosophers of Greece, pp. 239-243. + +CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + +1 (p. 180). Alfred William Bern, The Philosophy of Greece +Considered in Relation to the Character and History of its +People, London, 1898, p. 186. + +2 (p. 183). Aristotle, quoted in William Whewell's History of the +Inductive Sciences (second edition, London, 1847), Vol. II., p. +161. + +CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC +PERIOD + +1 (p. 195). Tertullian's Apologeticus. + +2 (p. 205). We quote the quaint old translation of North, printed +in 1657. + +CHAPTER X. SCIENCE OF THE ROMAN PERIOD + +1 (p. 258). The Geography of Strabo, translated by H. C. Hamilton +and W. Falconer, 3 vols., London, 1857, Vol. I, pp. 19, 20. + +2 (p. 260). Ibid., p. 154. + +3 (p. 263). Ibid., pp. 169, 170. + +4 (p. 264) Ibid., pp. 166, 167. + +5 (p. 271). K. 0. Miller and John W. Donaldson, The History of +the Literature of Greece, 3 vols., London, Vol. III., p. 268. + + +6 (p. 276). E. T. Withington, Medical History fron., the Earliest +Times, London, 1894, p. 118. + +7 (p. 281). Ibid. + +8 (p. 281). Johann Hermann Bass, History of Medicine, New York, +1889. + +CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +(p. 298). Dion Cassius, as preserved by Xiphilinus. Our extract +is quoted from the translation given in The Historians' History +of the World (edited by Henry Smith Williams), 25 vols., London +and New York, 1904, Vol. VI., p. 297 ff. + + +[For further bibliographical notes, the reader is referred to the +Appendix of volume V.] + + + + + +End of Project Gutenberg Etext of A History of Science, V 1, by Williams + diff --git a/old/1hsci10.zip b/old/1hsci10.zip Binary files differnew file mode 100644 index 0000000..315a1d8 --- /dev/null +++ b/old/1hsci10.zip |