diff options
Diffstat (limited to '1705.txt')
| -rw-r--r-- | 1705.txt | 8511 |
1 files changed, 8511 insertions, 0 deletions
diff --git a/1705.txt b/1705.txt new file mode 100644 index 0000000..daad328 --- /dev/null +++ b/1705.txt @@ -0,0 +1,8511 @@ +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: 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. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +http://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +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 + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, are critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at http://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +http://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at http://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit http://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including checks, online payments and credit card donations. +To donate, please visit: http://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart is the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + http://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. |