A History of Science - Volume 1

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.