Should we follow back the recorded history of any people now civilized, we would always find evidence of ceaseless change; and the writings of ancient historians like Herodotus and Caesar and Tacitus give a great deal of information about the barbarous conditions from which civilization evolved.

But much more is known that materially amplifies the account of human progress based upon documents alone. The student of existing human races early learns that social structure is a very varied thing. The natives of northern Africa now live in a semi-civilized state which is very like that of medieval England. In Siberia and the American Southwest are tribes that correspond socially with the barbarians of Europe described by Greek and Roman writers. The American Indians discovered by the earliest colonists, the Polynesians of a century ago, and the Fuegians of recent decades provide counterparts of the ancient stone-wielding people who were the savage ancestors of European barbarians. Hence the comparative study and classification of modern races establishes a scale of social grades which corresponds with the order of their historic succession, just as in a larger way the complete series of comparative anatomy from Amoeba to man displays the order of evolution from unicellular beginnings to the present culminating types. Savagery, barbarism, and civilization are the three major terms of this social scale, but by no means are they discontinuous, for many intermediate forms of organization occur which are transitional from one major type to a higher one.

In human social evolution the starting point is not so simple as the solitary unit from which insect societies evolved,—that is, an organism which lives alone and is associated with another of its species only at the time of mating. The lowest human beings now existing have some form of family organization, traceable to the more or less continuous unions formed among certain of the apes and even among many lower animals, and not a characteristic that belongs to mankind alone. The savage and his mate constitute the social unit out of which all else is built up; the man and the woman must perform all of the vital tasks demanded by nature. Fruits and vegetables must be secured from the wild forest or by cultivation; the flesh of game animals or of a human victim is no less essential for food. The savage is his own weapon maker and warrior; he himself builds the rude shelter for his family and fashions the canoe if such is required. He is also his own judge, recognizing no control save the dictates of his wishes and needs, for he does not consciously realize that he must obey the primal commands of nature to preserve himself and his family so that the species shall persist. In brief, the elementary family unit carries on all of the individual biological tasks of foraging, righting, home-building, and the like, and it also discharges the racial task of multiplying, quite as instinctively as it provides for its own maintenance.

By the union of several families, a primitive association arises, like that of the Veddahs in Ceylon. The primal duties of each family are unchanged, and their biological activities are identical, as in the protozooen colony of Vorticella or in a pack of wolves; but certain new relations are established. A member of such an inchoate tribe must not treat his confreres as he might a man of another group; robbery and murder within the limits of the small association are detrimental to communal interests, though they may remain unchecked if the victims are strangers. Cooeperation for mutual offense and defense makes the group stronger than its constituent family units taken singly, and every man of such a tribe gains something by looking out for others as well as for himself. By natural selection alone the bonds of union would be strengthened in direct proportion to the subordination of individual interest to group welfare, and to the amount of altruistic action that in a true sense grows out of purely selfish conduct.

But when such a primitive biological association forms and grows, an opportunity arises for increasing the effectiveness of the whole group by differentiation. Some of the men are stronger in battle and they soon become the chief warriors; others prove to be more skilful in the hunt or in the construction of canoes and weapons. Just as among the insects, the hunter seeks food not only for himself but for the warriors, who in their turn defend themselves, but do not cease fighting when they have disposed of their own enemies if foes of their comrades still survive. The barbarous state of society thus arises, and the division of labor brought about during its origin makes it possible and indeed essential for many family units to remain together for mutual good. The union is stable and efficient, however, only if the individual suppresses his own selfish inclinations, suspending private quarrels when public wars are toward, and acting at all times in concert with his fellows. Self-control increases necessarily, and lines of conduct deemed right by a solitary savage unit come more and more under the sway of social inhibition, for although the primitive savages must inhibit individualistic action to some degree, the barbarian must suppress much more of his purely personal wishes for the purpose of social solidarity. Thus it comes about that a barbarous community can number thousands, while a tribe of savages with a higher degree of individualism and less altruism cannot cohere if it comprises more than hundreds or scores.

Civilization is a product of evolution by precisely the same natural mode of development, that is, through further subordination of individual to communal interests and through progressive dividing up of the tasks necessary for the life of the group. The final result is so obvious and familiar that we take it for granted, accepting it as self-sufficient without realizing how it has come about and how modern is the present state of affairs. Let us compare the life of an Indian savage living on Manhattan Island four centuries ago with that of a New Yorker to-day, as regards so simple a matter as the procuring of fish food. The Indian emerged from his tepee, built by himself, and walking to the shore, stepped into a canoe which also he had made with his own hands. Paddling to the fishing ground, he patiently cast his line until the desired fish were caught. Does any one of us do all of these things for himself? We live in houses constructed for us by others who devote their lives to building; we are very apt to go about the city in conveyances that demand special and peculiar skill for their invention, manufacture, and operation. Arriving at a market-place, we obtain such an article of food as a fish without having to go out upon the water ourselves, for many other workers have built vessels that we do not know how to make and may not know how to handle, and hundreds of fishermen devote their lives to their special task, not for themselves, but for us and all others, such as the builder, the subway operator, the boat maker, and the manufacturers who supply their clothing and apparatus.

What has come about then is a higher degree of specialization in the performance of the fundamental biological tasks, resulting in the formation of coherent and efficient groups comprising millions as compared with the thousands of barbarism and the hundreds of savagery. Just so the communities of insects with the greatest degree of altruism and division of labor far exceed in numbers the small colonies of the social wasps with lower social differentiation.

But the great biological functions of an entire complex civilized society remain the same as those of a primitive savage family unit, of an insect community, of Hydra, and of Amoeba. Let any nation fail to maintain itself in material individual respects, it must inevitably die out; in the islands of the South Seas many a tragic death-struggle of a people can be witnessed. If in the second place a nation should concern itself too greatly with the material benefits of human life without obeying the natural mandate to propagate itself, its place in the scheme of things becomes insecure, as in the case of the French Republic. Natural social laws that go back to Amoeba must be observed, consciously or unconsciously, or else even the civilized community must fall, like scores and hundreds of others that lie along the road of historic progress—a road strewn with the remains of the unfit thrown out by natural selection.

What now are the lessons of social evolution and what guidance does science give for human endeavor? Although it may seem that the biologist leaves his field when he considers these questions, his duty would be unfulfilled if he neglected an opportunity to give his results their highest utility through their use for the betterment of human life.

The first lesson is that the history of human social organization is far from unique, and that it is identical with the process by which insect communities and cell-aggregates have evolved; in a word, the laws of biological association are uniform throughout the entire organic scale. In some respects evolution in mankind has yet to equal the heights attained by some insects, inasmuch as no human society has accomplished so rigid a specialization of its members that a given individual is foreordained by its inherited structure to be a particular kind of worker and nothing else. Furthermore, evolution in human society is still far short of a state where some and some only are reproductive members of the group while the others are necessarily sterile; social insects with stable colonies are so organized that the queens and drones are solely reproductive while the workers are destined to care for the material wants of the colony. It is true that the birth-rate is by no means the same in all classes of society, but the social and other adventitious restrictions that bring this about are not on the same plane with the hereditary determining factors which operate among insects. Therefore the scale of human communities proves to be only a part of the wider range of organic associations in general—a part which can be definitely placed in such a wider scheme and so become more intelligible in itself.

In all departments of social evolution, progress is made by the twofold process of combination and differentiation. We have dealt with detailed instances, and now it is profitable to treat the process in a larger way, with a view toward the possibilities of the future. The Thirteen Colonies, somewhat similar in their earlier economic activities, united for mutual support much as wolves combine to form a pack. Later, as circumstances directed, they differentiated into farming or manufacturing or commercial organs of the body politic, each to some degree freeing itself of the functions undertaken by others, and becoming thereby more dependent than before upon those that specialized in different ways. As in the history of the insects in a growing wasp community and of savages evolving into barbarians, the original condition of relative independence passed into a state of interdependence and cooperation. In like manner, if nature remains the same, as there is every reason to believe it will, nations now separate will unite to make more complex combinations that will be veritable empires of world-wide scope. Countries on opposite sides of an ocean are now more closely connected by lines of communication and means of travel than were the Carolinas and New England a century ago. Diplomatic activities give many signs of a growing appreciation of the value of reciprocal agreements for mutual advantage, and the Hague Conference is a concrete manifestation of a continuing process of social evolution that finds its beginnings and its interpretation far below human history in lower organic nature.

But perhaps the most important result of this whole discussion is the lesson of social service that it teaches. We are members of a vast community whose complex total life seems far removed from anything going on in an ant-colony, and our daily tasks vary greatly in specific character and degree when compared with those of lower communal organisms. It seems scarcely credible that any principles of social relationship, however general, can hold true for us and for them. But when the rock-bottom foundations are reached, they are simple and instructive indeed. Being here, we cannot escape our personal obligations as living things or our equally clear duties as members of our community. These facts being as they are, what must we do? Self-interest is rightly to be served, otherwise we would be incapable of discharging our secondary tasks, namely, those of service to others in ways that are determined by hereditary endowment and conditional circumstances. The difficulty is to find the right compromise between the two sets of obligations; but the right balance must be found, or else the health of the community is impaired. Should any class demand more than its just dues, others must suffer through the diversion of what they require, and the well-being of the selfish class is jeopardized to some degree, so closely interwoven are the interests of all. Freedom of opportunity within the limits of ability and efficiency is the right of every one, but freedom of conduct must never result in trespass upon the equal rights of others to make the most of their abilities and opportunities.

To summarize, then, social evolution is a continuous process accomplished through differentiation and division of labor among the components of biological associations. Although the total form remains the same everywhere, progress has been made in content through the further subordination of selfish to altruistic conduct; only by this means does an individual gain liberty to pursue the social task for which he is best fitted by nature.



VIII

EVOLUTION AND THE HIGHER HUMAN LIFE

We have now reached the last division of the large subject that has occupied our thoughts for so long. The present title has been chosen because the questions now before us relate to the highest human ideas belonging to the departments of ethics, religion, theology, science, and philosophy. These matters may seem at first sight to be far removed from the territory of the naturalist as such, and quite exempt from the control of laws which determine the nature and history of the human individual in physical, mental, and social respects. Yet one reason alone would impel us onward: we cannot close the present examination into the basic facts of evolution and into the scope of the doctrine without asking to what extent a belief in its truth may affect our earlier formed conceptions of nature and supernature. Heretofore these possible effects upon what may be dearly cherished intellectual possessions have received no attention, so that we might learn how evolution works in the lower fields of organic life in general and human life in particular without being disturbed by them. No doubt, however, the conviction has grown with each step in our progress that the principles we have learned must cause us to readjust our views of the highest elements in human thought to a degree that must be inversely proportional to our previous acquaintance with the laws and processes of nature. But the seeker after truth is fearless of consequences. He knows that truth cannot contradict itself; and if those to whom he looks for authority give him conflicting accounts of nature's history, he knows that one of these must be less surely grounded than the other. The investigator soon learns to withhold final judgment, realizing that the primary conditions for intellectual development are the plasticity and openness of mind that dogmatism and finality destroy. He knows that while his researches may be, and indeed must be, iconoclastic, they provide him with better icons in place of the old.

Let us recall the steps in our progress through one and another field of knowledge, from which representative facts have been chosen for classification and summary. We began with the basic principles of organic structure and workings, and then we examined serially the larger categories of the evidences relating to evolution as a fact, and to the mode of its accomplishment by natural factors. Proceeding to the special case of our own species, we learned that human beings are inevitably a part of nature and not outside it; in structure, development, and palaeontological history, mankind is subject to the control of the uniform laws which operate throughout the entire range of living things. Finally, the mental characters and the social relations of human organisms were derived from beginnings lower down in the scale, and were proved to be no more exceptional than the physical constitution of a single human being.

Are we to forget all of these things when we try to put in order our ideas belonging to the categories of higher thought? Can we hope to find the truth if we fail to employ the methods of scientific common-sense which only yield sure results? It is no more justifiable to discard our hard-earned knowledge than it would be for an advocate to undertake the conduct of a case in deliberate disregard of what he had learned of the law, or for a surgeon to leave his knowledge at the door when he entered the operating room. Too often we are bidden to view the larger conceptions of nature and supernature as something outside the realm of ordered knowledge too frequently we are given statements upon authority that takes no account of reason, and we are asked to accept these views whether or not they accord with the demonstrated facts of common-sense. But those who have followed the present description of evolution can readily recognize their obligation to use for the further analysis of higher human life the means which have given in that doctrine the most reasonable explanation of the natural phenomena already investigated.

I need hardly say that we now enter upon the most difficult stage of our progress. The regions we have traversed were more readily explored because they were remote from the matters now before us; even in the case of man's mental and social evolution it was possible to take a partially impersonal view of certain of the essential elements in human life, which we cannot do now. For ethics and religion and philosophy are groups of ideas that are familiar to us as the property of mankind alone. Countless obstacles are in the way. Much mental inertia must be overcome, for it is far easier to accept the average and traditional judgments of other men—to let well enough alone—than it is to win our own way to the heights from which we may survey knowledge more fully. Human prejudices confront us as a veritable jungle, hemming us in and obstructing our vision on all sides; and perhaps much underbrush must be cut away if we are to see widely and wisely. Nevertheless, to those imbued with a desire to learn truth, anything and everything gained must surely repay a thousand times all efforts to obtain clearness of vision and breadth of view. With our perspective thus rectified by our backward glance, we turn to the three divisions of human thought now to be examined. The conceptions of ethics come first for reasons that must be apparent from the classification of the facts of social evolution; just as mental attributes and communal organization are inseparable, so rules of conduct arise pari passu with the origin of a biological association. Religion and theology form the second division, which takes its origin in part from the first, for these two groups of ideas are largely concerned with the authority for right conduct and with human responsibility for taking the right attitude toward the entire visible and unseen universe. Finally, science and philosophy are briefly treated as evolved products which include within their scope all that there is in human knowledge; for this reason they take the highest place, instead of the position below religion usually assigned to them. At the last, having reached our final standing ground, we must look back in order that we may clearly define the lessons and ultimate values of the whole doctrine of evolution.

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Ethics is the science of duty. It is usually restricted to an examination of purely human obligations, and to a search for the reasons why men should do certain things and refrain from committing other acts. Like psychology and sociology, ethics began as a strictly formal and a priori system of dogmas which related to the life of cultured human beings alone. Again, like the sciences specified, it gradually broadened its scope so as to include the conventions of races lower in the scale than the civilized peoples who only were sufficiently advanced intellectually to conceive it. Thus the comparative method came to be employed, and in direct proportion to its use, more liberal views have developed regarding the diverse methods of thought and standards of social life and of conduct among differently conditioned peoples. Still more important is the demonstration that human ethics as a whole, like human faculty and civilization, takes its place at the end of a scale whose beginnings can be found in lower organic nature.

Those who have followed the account of social evolution given in the preceding chapter must realize that the basic general principles of natural ethics, as contrasted with "formal" ethics, have already been discovered and formulated. A biological association of whatever grade and degree of complexity is impossible unless biological duties are discharged. Human ethical conduct differs from insect and protozooen ethical conduct only in the element of a participation in the process by the explicit consciousness of man that he has definite obligations to others; and this distinguishing characteristic is the direct outcome of an evolution which adds reflection and conceptual thought to a mental framework derived from prehuman ancestors. The insect hurries about in its daily life as an animated machine, whose activities are defined by heredity; its special mode of conduct is just what nature has produced by selection from among countless other forms of living which have not had the same degree of biological utility. But man alone recognizes vaguely or clearly the "why and wherefore" of his acts that are far more instinctive than he supposes; he only is consciously aware of the bonds of kinship and economic interdependence. He looks about for the authority which imposes his duties and fashions his bonds, and conceives this authority as something superhuman, until the comparative studies of evolutionary phenomena reveal the true causes in uniform nature itself.

According to biological ethics, the fundamental obligations of all living things are the same, even though the modes of discharging them may be various. Every individual must lead an efficient personal life by procuring food, but animals differ very much in their alimentary apparatus; among other things they must respire, but some are so simply organized that they do not need elaborate organs like the tufted gills of a crustacean or the lungs of higher vertebrates. Every individual of whatever grade must also provide in some way for the maintenance of the species, but some, like a conger eel, produce enormous numbers of eggs which are left uncared for, while others, like birds, bring forth only a few young, which receive constant attention and protection until they are able to shift for themselves. Nature has no place for even a human community unless individual and racial interests are conserved, so that the greatest duties are definitely formulated—all else is secondary and less essential. Selfish action on the part of every unit is obligatory, but it must always be antecedent to endeavor in the wider interests of the race if the unit is a solitary individual; if it is a member of an association of any grade, then it must serve its fellows in some way. Egoism and altruism are natural essential guides to conduct; neither can safely exclude the other, and their antithesis sets a problem for every organism, which is to work out the proper compromise that will be most satisfactory to nature. The Golden Rule is taught by biology because it is demonstrated empirically, and not because it has any a priori value as an ideal ethical principle.

But utilitarian or natural ethics need not stop with the statement of vague generalities like the foregoing. In human society, as in the life of low animals, the worth and value of any form of conduct and of every single act can be estimated by definite biological criteria. The institution of marriage and the conventions of common morality have their biological value in their provision for the care of children; the safeguards of property rights enable the industrious—the biologically efficient—to keep the fruits of their labors; the establishment of formal civil and criminal laws is biologically valuable in a social way, in so far as such laws diminish the unsettling effects of personal animosity and the desire to wreak personal vengeance; the establishment and differentiation of legislative, executive, and judicial organs of government lead to greater social solidarity and higher biological efficiency. Thus unchecked individualism is just as wrong ethically and biologically among men as it would be in the case of insect communities, as pointed out in the preceding chapter; no one has a right to expect service or deference to personal interest from others if he fails to work for them and for the good of all. It is true that the social structure will stand a great amount of tension, but if this becomes too great, either a readjustment is effected, as when King John was forced by the barons to concede their rights, or else the whole nation suffers, owing to the selfishness of a few. In the war between Russia and Japan, the latter won because the individual soldier merged his individuality in the larger mechanism of the regiment and brigade and army corps, gladly sacrificing his life for the nation represented by the person of its Emperor. The single Russian soldier may have been far superior to a Japanese in muscular strength, and perhaps in arms also, but selfishness and greed on the part of many who were responsible for the organization and equipment of the Russian armies rendered the whole fighting machine less coherent and therefore less efficient than that of the Japanese.

In the evolution of ethics the recognition of ideals of conduct has followed long after the institution of a particular precept by nature, which is obeyed instinctively and mechanically by force of inheritance. In the case of the communities of insects, the results are the same as though the individual animal fully recognized the value of concerted endeavor. So among primitive savages of to-day there is only a vague conception of abstract duty as such, or it may be practically lacking, as in the case of the Fuegians. So also a growing child is substantially egoistic, and it must be taught by precept and example that the rights of others can be safeguarded only by the altruistic correction of personal action, long before the child can grasp the higher conceptions of ethics. If a human being never learns to do so, and becomes a criminal through force of heredity or circumstances, the machinery of the law automatically comes into operation to conserve the welfare of the community. Such a criminal may be unable to control his destiny, and may not be responsible for being what he is, but nevertheless he must pay the penalty for his unsocial heritage by suffering elimination.

Ethical systems are built around man's vague recognition of certain natural obligations, and they have thus become more or less complex, and more or less varied as worked out by different peoples. They must necessarily be much concerned with social questions, with morals in the usual sense and the more rigid principles enacted into the spoken and printed law, but they have also become closely connected with religion and theological elements. Especially is this true in the ethics of barbarous and savage peoples, who accredit the "categorical imperative" to some supernatural power, as we are to see in a later section. The one point that comes out clearly is that the systems of conduct and duties have evolved so as to be very different among various races, and that in the history of any one people, ethics has passed through many varied conditions. What may be deemed right at one period becomes wrong at another when conditions may be changed; in medieval England the penalty of death was prescribed for one who killed a king's deer, as well as for a highway murderer. The Fijian of a quarter century ago killed his parents when they became too old to be effective members of their tribe. And so deeply ingrained was this principle of duty that elderly people would voluntarily go to a living grave surrounded by their friends; while in other authentic cases, parents have first killed their sons who failed to obey the tribal law, and have then committed suicide. We can see how nature and necessity would institute a law requiring such conduct where a tribe must carry on almost incessant warfare and where the available food supplies would be enough for only the most efficient individuals. Infanticide also has been practised for reasons of biological utility, as among the Romans, who at first maintained their racial vigor by deliberately ordering the death of weak babes. But times have changed, and ethics has become very different with passing decades. Our civilization has resulted in a development of human sympathy as an emotional outgrowth of necessary altruism; this motive directs us through charitable institutions and hospitals to prolong countless lives which are more or less inefficient, but which do not render the whole body politic incompetent in its struggle for existence.

Nature then has itself attended to the development and institution of ethics. As we look back over the long series of stages leading to our own system of conduct the most striking feature of the history is the increasing power of self-control or inhibition. As a natural instinct this tends to prevent the committing of acts which for one reason or another are naturally harmful to society as a whole. What we call conscience is an instinct implanted by purely natural factors, and it unconsciously turns the course of human action in the directions of selfish and altruistic interests. Conscience, then, without ceasing to have validity and efficiency, appears on the same plane with all of the other products of evolution which owe their existence to individual or social utility.

Theology and religion involve intimately related conceptions of the world, its make-up, and its causes. Strictly speaking, religion is a system of piety and worship, while theology deals more particularly with the ultimate and supernatural powers conceived in one way or another as the God and the gods who have constructed the universe and have subsequently ordered its happenings. A religion is a group of ideas having the effect of motives; it is dynamic and directs human conduct. Theology, on the other hand, is more theoretical and descriptive, and its conceptions, together with those of other departments of human thought, give the materials for the formulation of the religious beliefs which determine the attitudes of men toward all of the great universe in which they play their part and whose mysteries they attempt to solve.

Defined and distinguished in these ways, these two departments of higher human life present themselves for comparative study and historic explanation. They differ much among the varied races of mankind, so much, indeed, that an investigator who approaches their study with a knowledge only of Christian religion and theology finds it difficult at first to recognize that the same fundamental ideas, although of far cruder nature, enter into the conceptions of an idol-worshiping fanatic living in the heart of Africa. But, nevertheless, beliefs that fall within the scope of the definitions adopted above are to be found among all men, and they must be examined so that their agreements and differences may be demonstrated, and their common elements may be explained as the natural products of a process of evolution.

Such a broad comparative study, like that of physical, mental, and social phenomena discussed heretofore, must be conducted objectively; that is, each and every particular belief of a religious or theological nature which can be discovered in any race is entitled to a place in the array of materials which demand scientific treatment. They must be verified, classified, and summarized, in order that their total meaning and value can be discovered. It must be strongly emphasized that for such purposes the inherent validity and truth or falsity of diverse religions are not called into question when they are so considered as objects of study; many still entertain the view that the mere task of conducting an analysis of a group of religious beliefs of whatever nature must tend to destroy or alter that system of religion in some way and degree. But whatever the comparative student may himself believe, the conception of Jehovah in the Hebrew religion is quite as legitimate an object of study as the Buddhistic concept of Brahma as the Ultimate Being, or the Polynesian idea of Tangaroa as the god of the waves. We would naturally be inclined to exclude the last from our own personal system of piety and worship as the childish concept of an imaginative, adolescent race; but whatever the truth may be, the fact of a belief in Tangaroa is as real as the fact of Christian belief in God. We can no more destroy any one of these ideas by investigating its nature and origin than we destroy the efficacy of the human arm when we study its muscles and bones and sinews. The former, like the latter, take their places among natural phenomena whose history must be inquired into if there are any reasons for supposing that they fall within the scope of evolution. I would be the last to lead or to take part in an attack upon any system of religion, but as a student who is interested in the universality of organic evolution, I am forced to scrutinize each and every authentic account of a religion to see if such systems present objective evidence of the fact of their evolution through the operation of purely natural causes.

But before passing to a detailed treatment of the analysis, synthesis, and genesis of religious systems, let us employ our common-sense for a brief backward glance over the known history of familiar facts. Every one is aware that the Christian religions of our time and community have not existed forever; this, indeed, is indicated by the way the passing years are denominated. We call the present year 1907 Anno Domini, and this whole expression explicitly refers to the fact that less than two thousand years ago the Christian systems of piety and worship collectively took their origin from their Hebrew ancestor. The same parent has produced the relatively unchanged Judaism of the present day. Judaism itself evolved under the influence of the Prophets, of Moses, and of Abraham. Turning to Asia, we learn how Buddhism evolved from Brahmanism. The teachings of Mohammed at a later time developed into the formulated precepts of the Koran. Would any one venture to assert that all or any of these systems of thought have stood firm and immutable from the finite or infinite beginnings of time? Would any one contend that the creeds of Protestantism have remained unchanged even during the past twenty years? Like all departments of human belief and knowledge, religious concepts have obviously altered in natural adjustment to changing times and to advancing conditions of human intellect; and the question turns to the mode by which they have been modified, to see whether natural causes of evolution have changed them, and have originated their earliest beginnings at the very outset of human history. It has been stated above that every race of mankind, however primitive or advanced it may be, holds some form of religious belief based upon some conception of the supernatural powers back of the world; and what the universe is conceived to be must largely determine the particular characteristics of a theology, and through this the special form of its attendant religion. We have before us a wide array of types to study and to compare, which vary so greatly, partly for the reason specified, that an inclusive definition of religion must be couched in very general terms. If we define it as the attitude and reaction of a human being conditioned by his knowledge of the immediate materials and his conception of the ultimate powers of the universe, its scope is so extended as to include the ideas of the atheists and agnostics as well as the crude conceptions of lower races and those systems of piety and worship conventionally regarded as religions by civilized peoples. More than this: we cannot regard the total reaction of a thinking being as essentially different in ultimate value from the attitudes toward their worlds of animals lower than man. The situation of a well-trained sheep dog is one of pastures and fences and gates, of rain and sunshine, of sheep, and of a master whose voice is to be obeyed. What the dog may do is partly determined by what it finds in its world of animate and inanimate things. Although the animal's "conception" of such things must be far simpler than a human being's, nevertheless its life is lived in reaction to all of its surroundings as they are presented to its cerebral apparatus by the proper organs. So in the human case, conduct is directly affected by the living and lifeless objects of a total human situation, the only difference being that reflective consciousness and reasoned interpretation have their share in determining the assumed attitude in ways that seem to have no counterparts as such in the mental lives of lower animals. But whether or not the similarity between human religion and lower organic reaction be admitted,—and the admission is one that greatly facilitates an understanding of evolution in this field,—the general resemblance of all religions in fundamental character at least must be accepted.

Another general feature of religious systems is their complexity. The essential elements of all of them are few indeed, as we shall see at a later point; they are beliefs regarding ultimate powers, human responsibility to such powers, and future existence. These have taken one specific form or another in various lines of racial evolution, but aside from their own changes they have gathered about them many other articles of creed relating to other departments of thought and life. Ethical rules of conduct are so added, as in the Hebrew religion where the idea of Jehovah involves God the Ruler and Judge who imposes and administers the laws of right living. Social customs are almost invariably intertwined with religious views, among savages as well as among the more advanced Mohammedans whose rules relating to family organization form an integral part of the whole cult. The emotional elements play a large part in some cases, in the fanatical creeds of the Dervish and Mahdist and in the "revivals" under nearer observation. In Greek cosmology and worship, aesthetics figured to a large degree. Temperamental and other psychological characteristics have profound effects upon religions, which we may illustrate by such extreme examples as the austerities of New England and Scotch Presbyterianism and the contrasted liberties of the natural religions of tropical races. But all of these accessory elements belong to other well-defined departments, some of which have already been considered, and among the materials of their proper divisions they find their interpretation and historical explanation in evolution. It is with the basic elements themselves that we are now concerned.

Only within recent years have systematic attempts been made to classify religions on the basis of impersonal objective study. Throughout all times men have instinctively set up their own religion as the only true one, besides which all others are designated simply as false—a very natural distinction, but one which is too naive for science, as well as one that takes into account subjective or personal values which are not to be considered in an objective comparison and analysis. The linguistic basis was first employed by Mueller, with the result that religions were placed in the category of evolutionary accompaniments of the other mental possessions and of the physical qualities of genetically connected peoples. Thus the nations of Europe that branched out in all directions from very nearly the same sources possessed common linguistic characters and somewhat similar creeds. The Sanskrit-speaking races were the original Brahmins and Buddhists. Ancestor worship is an accompaniment of the peculiar languages spoken by eastern Mongolian peoples. And although the correlation specified is by no means invariable, because a race of one stock can readily accept the religion of a neighbor or of a conqueror, yet much is gained through the introduction of the idea of evolutionary relationships.

A more logical classification frankly adopts the genetic method and clearly recognizes the direct effects of cultural and intellectual attainments upon the way a religious system becomes formulated. In such an arrangement, similar to that of Jastrow, religions can be classed as those of savagery, of barbarism, of advanced culture, and of civilization. Among the first named, notably those of Polynesian and African tribes, beliefs in diversified ghosts and spirits bulk largely, and every moving thing, be it a river or a cloud or a tree or animal, is held to be animated by an invisible conscious genius; the spirits reside in everything, as well as in the great unknown beyond. Above these in the scale are the religions of so-called primitive cults, more elaborate and formalized in the ancient beliefs of Egypt and Assyria, but still below those of advanced culture, which make up a third group. The fourth class includes the religions which tend to be coextensive with life, and which enjoin the higher harmony of practical and theoretical conceptions. Taking Christianity as an example, the contrast with the beliefs of savagery brings out clearly the nature of progressive development. Here religious thought is no longer esoteric, confined to a chosen sect like the Levites among the Hebrews or the shaman and medicine-man among the American Indians; nor is religious observance restricted to the innermost shrine of the tabernacle or sacred dwelling, accessible to few or only one. It comes to be regarded as something in which each and every individual can participate, and a personal possession that has a direct part in determining all forms of human life and action. This is another way of saying that the more highly evolved religions owe their character to the greatly varied and abundant intellectual elements which are built into them. And this is why religion in the highest form, more clearly than in the lowest forms, is to be spoken of as an outlook upon the world which is determined by the total intellectual equipment of the individual man who thinks about the universe and directs his course of action by what he finds.

* * * * *

We come now to a closer concrete study of the basic elements of religion; that is, of those beliefs that are invariably present, in one form or another, in every system of piety and worship, and that constitute the innermost framework beneath the secondary creeds added to them. Following Mallock and others, we may distinguish three such elemental conceptions. These are, first, the belief in the existence of a supernatural being or beings, endowed with intelligence like, but superior to, our own; second, the idea of human responsibility to this or these powers; and, third, the belief in immortality as an attribute of the supreme powers and of human individuals also. Let us see how these beliefs appear in characteristic systems of religion.

In all forms of Christianity the central idea is the conception of a triple unity personified as God. He is regarded as the Creator who has made all things and who demands reverence from his subjects. He is the Author and Finisher of the faith as well as the sole Cause of the universe itself. Much of this element is directly derived from Judaism, the progenitor of Christianity; but a difference consists in the triple nature of the supreme being according to the newer creed. As the original and supreme being, God is not only the Creator, but the watchful Judge as well, demanding reverent obedience to the laws of the world in which he has placed man, and imposing sacrifices and penitential observances when his mandates have been disobeyed. As the God of Mercy he is incarnated in the person of Jesus of Nazareth, and offered as a vicarious sacrifice for sinners who are thus enabled to escape the penalties they would otherwise have suffered. As the Holy Ghost, God is the vaguely personified ultimate source of the higher and nobler elements of human thought, aspiration, and life in general. The second basic tenet of Christianity is that of human responsibility to God, to whom man is related as the created to a creator, as a subject to a ruler, and as one saved to his redeemer. The institutions of sacrifice and ritual are outward signs of human subjection to God himself and to his laws, according to which the universe is conceived to operate. Finally, Christianity teaches that just as God in his single and triune form is eternal, so the soul of man is immortal, with or without its earthly temple of flesh and blood. The essential thinking individual is believed to pass to heaven, where rewards for right living are bestowed, or to hell, in order to suffer punishment for sin during all eternity, or some part of it, according to different views regarding the efficacy of Christ's vicarious atonement.

It is true that the manifold sects of Christianity differ somewhat in the detailed forms of these three essential beliefs, but not to the same degree as in the case of the secondary additions. God's laws, Christ's teachings, and the inspiration of the Holy Ghost are the recognized guides to conduct; but human frailty has been such that the history of Europe presents a panorama of warring sects in almost unceasing strife about details of ritual and interpretation, while the great fundamental truths have been too frequently ignored. The conflicts of Catholics and Protestants, Puritan and Cavalier, and Northern and Southern Presbyterianism, have not been waged on account of basic beliefs like the three outlined above, or about the Golden Rule, but on account of comparatively trivial details which to the impersonal student have scarcely more than the value of individual preference.

Judaism, the next great religion, has already been mentioned as the parent of Christianity, to which it gave the concept of a Supreme Being, as well as that of a Messiah. It is a purer monotheism than its outgrowth, whose trinity is more like certain elements of Greek theology. Jehovah is the one supernatural power, the creator and lawgiver and immediate cause of all the workings of nature. It is he who shapes the world out of nothingness and who separates the waters from the dry land; he parts the waters of the Red Sea to save the Israelites, and brings them together again to overwhelm the pursuing hosts of Pharaoh. It is his voice that thunders from Mt. Sinai, and his finger that traces the commandments to rule the lives of his chosen people upon the tablets of stone intrusted to Moses the Seer. At the behest of Joshua he holds the sun and the moon in their courses above the vale of Ajalon so that there will be more time for the destruction of the Philistines. In brief, Jehovah is the eternal god of law and power, demanding sacrifice and priestly atonement, and promising happiness eternal upon the bosom of Abraham to those who recognize their responsibility to him and obey his precepts. Again, there are three fundamental beliefs, that differ from those of Christianity as the Talmud diverges from the New Testament scriptures.

Mohammedanism is another outgrowth from this group of religions. The teachings of the Koran give the institutional and ritual forms to the same three elements distinguished above. God is the identical single God; and Mohammed is His Prophet, as Jesus is the New Prophet of Christendom. The true believer's responsibility entails active warfare upon the heretics, that is, those who do not accept the Koran. The immortal state of Mohammedanism is a very different thing from the heavenly bliss of Christianity, for the promised rewards are such as would appeal to the warm-blooded Southern temperament.

Turning now to Asia, we find in Brahmanism and Buddhism two systems of religion that are related to one another exactly as are Judaism and Christianity. The analogue of the Old Testament is a group of priestly hymnal writings known as the Vedas, which date back to about the fourteenth century before Christ lived. Their objects of worship at first are numerous invisible beings that actuate the things of the world, as in Greek theology, but later one of them assumes preeminence as the all-pervading essence of things,—Brahma. The precepts of Brahmanism enjoined adoration of the unseen powers and of their works, as well as practical rules of human conduct, such as those which divided a man's life into the four periods when he should be successively a student, the head of a family, a counselor, and a religious mendicant who should renounce the world of social activities and human desires. In earlier writings, the immortal state is a kind of heaven, but later it meant simply an absorption into Brahma, the eternal impersonal being.

Buddha was an orthodox Brahman reformer of the sixth century before our present era, just as Jesus was an orthodox Hebrew reformer. The essential creed of Buddha made his religion far more ethical than earlier forms, and placed it on a plane even above Christianity of later centuries. This creed relates to the element of human responsibility particularly, the other two remaining much as they were found by Buddha. According to his teachings, a man rested under an obligation to live nobly in the truest sense, and he acquired merit—karma—or lost it, in proportion to his deserts. At death a human soul is reincarnated, in a lower form of animal or even in a being residing in one of a series of unseen hells, if punishment is due; if a higher state is merited, progress is made through thousands of existences until perfection is rewarded by an eternal fusion with the essence of Brahma. It is because there is no escape from just punishment that Buddhism in its original form is properly denoted more ethical than a religion which teaches that sacrifice of any kind will exempt the sinner from deserved penalties and bring about the bestowal of unearned rewards.

Polytheism is the name given to a religion such as that of the Greeks or Romans, who believed in many gods and spirits of greater and lesser power. These supernatural beings, each in its own sphere, immediately directed the processes of nature and controlled the lives of men. One of them, Zeus, was regarded as the supreme "father of gods and men," who delegated specific duties to others; Ares was the god of battles, Hermes was the messenger, Athena implanted wisdom in the minds of men, and Poseidon ruled the sea. The gods were very human to the Greek mind, living in Olympus as men do upon earth, and even visiting the mortals. Their worship involved propitiatory sacrifices and rites as well as thanksgiving offerings when favors were bestowed. But although they were immortal, they did not allow the immortal souls of human beings to join them in their elysium, but compelled the disembodied shades to wander unhappily among the tombs and about their earthly abodes.

Roman theology and religion comprise almost identical forms of the three fundamental elements. The names are changed, and Zeus becomes Jove, his wife Hera is Juno, Ares is Mars, and Hermes is called Mercury. In all other respects, however, the two systems are as much alike as the Greek and Roman languages and Greek and Roman physique.

The religions of savagery are far less analytical, and much more naive in their reference of natural happenings to the direct interposition of malevolent and benevolent spirits. Their gods are numerous as in Greek religion, and likewise one of them is usually set up as the superior deity, to be the Tirawa of the Indian, the greater Atua of Polynesia, and the Mumbo Jumbo of a West African negro. There is no centralization of the supernatural powers, as in the Jehovah of Judaism and the still subtler Brahma of the Asian. Then, too, the gods must be concretely materialized for purposes of worship and sacrifice; consequently idols are made, to be regarded as the actual spirits themselves permanently or for the time being, and not viewed as representations of an ideal, like the statues of more advanced peoples. The immortal state is described in low religions in various ways that seem to be determined by what the believer himself most desires. The spirit of an American Indian goes to the happy hunting-grounds, where it mounts a spirit pony and forever pursues the ghosts of bison which it kills with spirit bow and arrows; to provide these necessaries his earthly possessions are laid beside his dead body. The Norseman was conducted to Valhalla and, attended by the Valkyrie as handmaidens, he eternally drank mead from the skull of an enemy and gloried over his mundane prowess in battle. It is unnecessary to expand the foregoing list, because the examples sufficiently represent the various grades of human religions. Regarding them as typical, we can see how universal are the three fundamental ideas with which we are concerned. Every race has its own conception of future bliss, as well as its conception of responsibility to the immortal and supernatural powers of the universe. Whatever may be the actual reality, and however closely the conceptions of one or another religion may approximate to the truth, such reality and approximation are not the subjects of the present discussion. Nor is it our purpose to bring out more explicitly the genetic relationship of one religion to another; the evolution of Buddhism from Brahmanism, the origin of Christianity from Judaism, and the divergent development of the several creeds of Christendom amply illustrate the nature of religious history. It is evolution here as elsewhere and everywhere.

* * * * *

Having distinguished the three general elements of all religions, beyond which everything else is of minor importance, we now turn to the question as to the natural origin of these elements. Clearly they cannot arise independently, for the belief in supernatural and eternal spirits is closely connected with the conception of an immortal soul.

The first is the conception of infinite personalities that later become more or less merged into one supreme being. This begins with the idea of the soul as the human ego, conventionally regarded as something independent of the material body during life and immortal after death. The savage goes to sleep, and in his dreams he goes upon journeys and battles strenuously with other men and with beasts, only to find when he awakes that his body is not fatigued, and that it has not really taken part in the activities of his dream life. His companions about the fire also tell him that this is so, while he is equally sure that his essential self has been doing many things during the interval of sleep. In his dream life he finds himself joined by others whom he knows are dead. He sees again even those whose bodies he may have assisted in eating. His total world very soon comes to have an unseen region which is the abode of ordinarily invisible beings having the forms of men, with whom his own dream person can associate; this unseen sphere is furnished also with ghostly counterparts of the trees and rocks and waters with which he is familiar when he is awake. Before long his soul or ghost or spirit is conceived as something which possesses two qualities: it can be disassociated from his body and enter the spirit-world where it seems to defy all the laws of waking life, for with the quickness of thought it visits neighboring islands as readily as it passes to the next hut; and it possesses immortality, for it is exactly like the persistent spirit-individualities of those who have died before him. The other cause for the development of the conception of gods and God in the mind of the savage is the fact that things have been made which neither he nor any other man can make. He can dig a ditch, and make a house, and fashion a canoe, and build ramparts of earth; but human power has obviously been insufficient to construct rivers and mountains and forests and their denizens. Mankind itself has certainly been made in some way, for it exists. Because the savage cannot conceive of things being made excepting as they are made by the human hand, and because so much confronts him that is beyond the power of human construction, he comes to postulate the existence of man-like, but greater than human, personalities, and as he cannot see them in the light of day, they belong to the spirit-world to which souls go. Imagination sometimes gives human outlines to shadows among the moon-lit trees, so that elves and pixies, nymphs and fairies, become established in the world as the primitive man conceives it. Larger tasks are discharged by more important spirits, and everything natural thus becomes animated by supernatural beings. Thor was the god of thunder; Freia the goddess of spring and vernal awakening; Athena inspired the minds of men. Venus and Aphrodite played their special parts, also. But such powers as these, established by the untutored mind, needed to be accounted for, and so in the more advanced religions Jove and Jupiter were created as the more ultimate causes, in response to intellectual demands. By combining all powers into one, God and Brahma are the results.

Thus in merest outline the conception of the infinite personality works out its evolution. At all times, among primitive and higher religions, the powers are clothed with human forms, and gods are pictured as men endowed with intellects and passions, and motives of vengeance and benignity. Man cannot shape his postulated deities save in such forms, with the possible exception of the most philosophical concept of all, Brahma.

The second fundamental belief, namely, in immortality, owes its origin in greatest measure to the psychological processes described above. Another potent factor, however, has been the natural desire to continue existence hereafter, usually in order to reap rewards not bestowed here. This desire is implanted by nature through the operation of purely biological factors, and it has the value of an organic instinct. To specify more particularly, nature has placed every organic individual under the necessity of doing its utmost to prolong its own life in the interests of itself, of others of its tribe, and of its species. Extinction is not faced willingly by a human being endowed with full consciousness any more than it is passively tolerated by a lower animal which instinctively struggles with its foes until death. So the desire to continue alive—the "will to live"—is a natural instinct, which combines with the belief in persistent disembodied spirits and, no doubt, with many other elements, to develop the basic conception of some kind of an immortal existence.

The third element, human responsibility to the infinite personality, is variously recorded in lower and higher religions. Its conception grows partly out of the feelings of awe and terror inspired by great works of nature such as the thunder-storm, the cyclone, and the volcano, while the orderly and regular workings of even everyday nature seem to demonstrate the direct control of the powers who rule man as well. The savage sees his crops destroyed by a tempest or drought; he attributes the disaster to the particular powers concerned with such things whom he must have angered unwittingly, and whom he must propitiate by sacrifice or penitence. His individual and tribal acts do not always accomplish the desired ends, and again the laws of infinite and ultimate powers must have been contravened, as he interprets the situation. Therefore his whole religious consciousness was exerted in the direction of finding out what was the ultimate constitution of nature, with which human activities must harmonize if they are to be successful. Bound by custom and convention and biological law, he looks about wonderingly to find the external authority for his bonds. To his mind this authority must be the host of spirits and gods who had made him and the things of his world. It is in this way that so many ethical elements have found places in religious doctrines, to be viewed as absolute rules of conduct coming from outside of nature, and not from nature itself, in the way the earlier sections of this chapter have shown.

Let us now summarize the results of the foregoing brief survey, conducted by the identical methods employed for the analysis of other bodies of fact. We have sought for those characteristics which are common to all religions of whatever time and place and race. Combined with many secondary and adventitious elements of other fields of thought and action, such as social, political, ethical, and psychological factors, they have proved to be the three essential beliefs in God or gods, human responsibility, and immortality. As a veritable backbone, they underlie and support the whole body of religious doctrine and organs of thought formed about them. We have seen, furthermore, that a natural explanation of the way these elements have originated can be discovered by the comparative student of religion, who describes also how they have variously evolved among different peoples. In all of this we have not questioned at any time the validity or reality of any one of these concepts; to ask whether or not they correspond actually to the truth is beyond our purpose, which is simply and solely to inquire whether even these mental conceptions furnish evidence of their evolution in the course of time. I believe that such evidence is found, and I believe also that this discovery must be of the greatest importance to everyone in formulating a system of religious belief, but the construction of this is not the task of science as such. Every individual must work out his own relation to the world on the basis of knowledge as complete as he can make it, but every individual must accomplish this end for himself. Because no two men can be exactly alike in temperament, intellect, and social situation, it is impossible for entire agreement in religious faith to exist. One's outlook upon the whole universe is and must be an individual matter; science and evolution are of overwhelming value, not by directing the mind to adopt this or that attitude toward the unseen, but by providing the seeker after the truth with definite knowledge about the things of the world, so that his position may be taken on the sound basis of reasonable and common-sensible principles.

* * * * *

When we take up science and philosophy, or knowledge as a whole, after religion, it may seem that we have reversed the proper sequence. There are many reasons for following this course, inasmuch as "knowledge" is the all-inclusive category of thought; our world is after all a world of individual consciousness and ideas. In dealing with religion, ethics, social organization, and human culture, we have been concerned with the evolution of so many departments of thought and action; and now we are to develop a final conception of evolution as a universal process in the progress of all knowledge.

Let us look back over the history of mathematics. The primitive human individual did not need to count. He dealt with things as he met them, and he disposed of them singly and individually. A squirrel does not count the nuts it gathers; it simply accumulates a store, and it perishes or survives according to its instinctive ability to do this. Just so was primitive man. The savage, when he organized the first formed tribes, learned to count the days of a journey and the numbers engaged on opposite sides in battle. He employed the "score" of his fingers and toes, and our use of this very word is a survival of such a primitive method of counting. The abacus of the Roman and Chinese extended the scope of simple mathematical operations as it employed more symbolic elements. With the development of Arabic notation capable of indefinite expansion, the science progressed rapidly, and in the course of long time it has become the higher calculus of to-day. The conceptions of geometry have likewise evolved until to-day mathematicians speak of configurated bodies in fourth and higher dimensions of space, which are beyond the powers of perception, even though in a sense they exist conceptually. The behavior of geometrical examples in one dimension leads to the characteristics of bodies in two dimensions. Upon these facts are constructed the laws of three-dimensional space which serve to carry mathematical thought to the remoter conceptual spaces of which we have spoken. It may seem that we are recording only one phase of mental evolution, but in fact we are dealing with a larger matter, namely, with the progressive evolution of knowledge in the Kantian category of number.

Natural science began with the savage's rough classification of the things with which he dealt in everyday life. As facts accumulated, lifeless objects were grouped apart from living organisms, and in time two great divisions of natural science took form. Physics, chemistry, astronomy, geology, and the like describe the concrete world of matter and energy, while the biological sciences deal with the structure, development, interrelationships, and vital activities of animals and plants. Surely knowledge has evolved with the advance in all of these subjects from decade to decade and from year to year. And just as surely must evolution continue, for the world has not stopped developing, and therefore the great principles of science must undergo further changes, even though they are the best summaries that can be formulated at the present time.

Philosophy deals with general conceptions of the universe. When we look back through the ages we find men picturing the world as an aggregate of diverse and uncorrelated elements—earth, air, fire, and water. The synthesis of facts and the construction of general principles down through Bacon, Newton, and Schopenhauer to modern world conceptions results in the unification of all—"the choir of heaven and furniture of earth." The lineal descendant of the long line of ancestral philosophies is the monism which sees no difference between the living and lifeless worlds save that of varying combinations of ultimate elements which are conceived as uniform "mind-stuff" everywhere. Whether or not this universal conception of totality is true, remains for the future to show. For us the important truth is that here, as in all other departments of knowledge, evolution proves to be real.

* * * * *

In closing the present description of the basis, nature, and scope of the doctrine of evolution, I find great difficulty in choosing the right words for a concise statement of the larger values and results of this department of science. So much might be said, and yet it is not fitting for the investigator to preach unduly. The lessons of the doctrine must be brought home to each individual through personal conviction. But because I firmly believe in the truth of the statement made in the opening pages, namely, that science and its results are of practical human value, it is in a sense my duty as an advocate of evolution to make this plain.

The method of science is justified of its fruits. At the very beginning we learned how, and how only, sure knowledge can be obtained and how it differs from a belief which may or may not correspond with the truth. Based upon facts of smaller or larger groups, scientific laws are so many summaries of past experience, and they describe in concise conceptual shorthand the manifold happenings of nature. Their difference from belief inheres in their ability to serve as guides for everyday and future experience. This entire volume is a plea for the employment of common-sense as we look upon and interpret the world in which we have our places and in which we must play our roles. Our search for truth will be rewarded in so far as we organize our common-sense observations into clear conceptions of the laws of nature's order.

The doctrine of evolution enjoins us to learn the rules of the great game of life which we must play, as science reveals them to us. It is well to remember that a little knowledge is a dangerous thing, but because evolution is true always and everywhere, an understanding of its workings in any department of thought and life clears the vision of other realms of knowledge and action. Perhaps the greatest lesson is at the same time the most practical one. It is that, however much we may concern ourselves with ultimate matters, our immediate duties are here and now, and we cannot escape them without giving up our right to a place in nature. We are taught by science that we live under the control of certain fundamental biological, social, and ethical laws; we might well wish that they were otherwise, but having recognized them we have no recourse save to obey them. Evolution as a complete doctrine commands every one to live a life of service as full as hereditary endowments and surrounding circumstances will permit. Thus we are taught that the immediate problems of life ought to concern us more than questions as to the ultimate nature of the universe and of existence.

Every one can find something worth while in the lessons of evolution, summarized in the foregoing statements. The atheist, who declines to personify the ultimate powers of the universe, may, nevertheless, find direction for his life in the principles brought to light by science. The agnostic, who doubts the validity of many conventional dicta that may not seem well grounded, can also find something to believe and to obey. Finally, the orthodox theist of whatever creed may discover cogent reasons for many of his beliefs like the Golden Rule previously accepted through convention; and he must surely welcome the fuller knowledge of their sound basis in the materials and results of comparative analytical study. To every one, then, science and evolution offer valuable principles of life, but great as their service has been, their tasks are not yet completed, and cannot be completed until the end of all knowledge and of time.



INDEX

Achatinellidae, 103, 104.

Activities, instinctive and reflex, 203, 205, 208; of familiar animals, 208, 209; differ from instinct, 209, 210.

Adaptation, universal relation to environment, 15; principle of, 17; degenerate forms enlarge our conception of, 50; results of larval short cuts in development, 71; 109, 213.

Africa, fauna of, 103, 164, 165.

Agassiz, a believer in special creation, 98.

Ages, Palaeozoic, 92; Mesozoic or Secondary, 93, 94; Cenozoic or Tertiary, 93; Coal or Carboniferous, 94.

Albumen, of egg, 60.

Alligators, a diverging branch of lizard, 45.

Amoeba, 21, 51, 69; comparative study of, 203, 205, 231, 247, 251, 254, 257, 258, 259, 265, 266.

Amphibia, frogs, salamanders, a lower class, 45, 62; order of evolution of, 63; evolved from fishes, 64; most primitive backboned animals, 92; 94, 157; embryos of, 171; 200.

Anatomy, of mind, 202.

Ant-bears, 42.

Anthropoidea, 160.

Anthropology, 177; methods and results of, 186; types of, 186, 187; comparative, of mind, 211.

Anthropometry, 177.

Ants, communities of, 125; mental life of, 207, 208; organizations of, 260, 263, 264.

Apes, 158; susceptible to training, 210; line from Amoeba, 231.

Appendix, vermiform, 168.

Apteryx, wingless bird of New Zealand, 44, 200.

Arachnida, 49.

Archaeopteryx, a famous "link," 99.

Ares, 300.

Armadillo, 42.

"Arts of life," 226-230; dwellings of men, utensils, 227; history of clothing, 228; arts of pleasure, 228-230.

Atom, carbon, 22; nitrogen, 23; hydrogen, oxygen, 24; chemical, 25.

Atua, 301.

Azores, animals of, 103.

Bacteria, amazing production of, 123; relation of, 127.

Baldwin, 148.

Bandicoot, 42.

Barnacles, really crustacea, 50.

Bats, 41, 94.

"Beagle," 102, 117, 136.

Bear, 38, 39.

Bees, mental life of, 207, 208; nervous system of, 232, 256, 257; organizations of, 260, 261, 262; queen, workers, 262, 263.

Beetles, 67.

Bernier, 183.

Bertillon, 183.

Birds, 44; have they descended from gill-breathing ancestors? 61; evolution of, 63; primitive, 99; embryos of, 171, 200.

Blastula, 68.

Blumenbach, 183.

Bonnet, 70.

Borneo, 164.

Brachiopods, 95.

Brahma, 299, 304.

Brain, 215, 235-240.

Brontosaurus, 94.

Brown-Sequard, 148.

Buddha, 299.

Buffon, 114, 135.

Butterflies, 67, 206, 207, 259.

Carbohydrate, 23, 24.

Carbon, atom, 22; 25, 27.

Carnivora, 35, 37, 38, 39, 40; order of, 157.

Caterpillar, larva of, 259.

Cats, Manx, Angora, Persian, 37, 39; domesticated, 137; intelligence of, 208, 209.

Cattle, products of human selection, 137; resemblance, 157.

Cebidae, true monkeys, 160, 161, 162.

Cells, 19, 20, 21; sex, 144; human, composition of, 156; of ectoderm and endoderm, 255, 256, 257, 258.

Celts, 218.

Cercopithecidae, 160, 162.

Cerebrum, 215.

Cetacea, 40.

Chemical transformation, 17.

Chick, development of, 60, 61.

Chimpanzee, 163, 164, 195.

Chromatin, 143, 144.

Civilization, a product of evolution, 272.

Classes, 32.

Classification, 32.

Clifford, 238.

Coccyx, 168.

Communities, cell, 258; insect, 258, 260-264.

Comparative anatomy, 35, 37, 39; any form will disclose development, 57; amphibia evolved from fishes, 64; Law of Recapitulation, 66; insects arisen from wormlike ancestors, 67; larvae of insects, 67; higher animals evolved from two-layered saccular ancestors, 68; 70, 71; supplements comparative embryology, 72; appearance of great classes of vertebrates, 94; proves order of evolution, 163.

Composition, chemical, 15.

Compounds, organic, 29.

Conger-eel, 123, 124, 127.

Consanguinity, essential likeness, 54.

Conscience, 287.

Consciousness, human, 234, 235.

Crabs, 48, 49, 66; hermit, 66.

Crustacea, lobsters, crabs, 48, 49; barnacles, 49, 50; 82.

Cuvier, 158, 78; a believer in special creation, 79.

Curve of error, 120.

Cyclones, 85.

Cyclostomes, 156.

Daphnia, 205.

Darwin, Charles, 80, 100, 102, 115, 116, 117; Origin of Species, 116, 124, 130, 132, 135; Erasmus, 135, 136, 138, 142, 143.

Deer, 42; fossil, of North America, 97, 98.

Development, 54; a natural process, 56.

De Vries, 145, 146; his mutation theory, 147, 148.

Dinosaurs, 94.

Distribution, geographical, 32.

Dogs, 38, 39; embryo of, 66; varied forms of, 137; pointer, sheep-dog, instincts of, 208; intelligence of, 208, 209.

Dubois, 173.

Ducksbill, or Ornithorhynchus, bottom of mammalian scale, 43.

Ducksworth, 184.

Eagle, 44.

Earthquake, 85.

Echidna, bottom of mammalian scale, 43.

Ectoderm, 255.

Egg, of common fowl, 60; of frog, 68; nuclei contains factors of development, 71; 144, 145; human, 231.

Eimer, 148.

Elements, chemical, 15.

Elephant, 41; place in zooelogical science, 95; 96, 97; age of, 124.

Embryo, of frog, 58; of chick, 60-62, 63, 64, 65; embryos of carnivora, rodents, hoofed animals alike in earlier development, 65; of cat, dog, rat, sheep, rabbit, squirrel, cattle, pig, 65; of skate, shark, hammerhead, 66; the human, 168, 170, 171; of birds, reptiles, amphibia, 171; human hemispheres of brain like adult cat or dog, 215.

Embryology, 32, 33, 34; of no form fully understood, 57; general principles of, 57-67; embryonic agreement, 65; of insects, 67; weight of facts of, 69; comparative, a distinct division of zooelogy, 70, 71; 76, 94, 100; evidence of, 170; of mind, 202, 214; in early stages of human, no nervous system present, 214; development of, 215.

English sparrow, 123, 127.

Environment, 111, 112; influences of, 126; determines mode of life of a race, 213.

Epoch, Glacial, 86; Silurian and Devonian, rich array of types, 93; Cenozoic, 96.

Erosion, 89.

Eskimo, picture-writing, 223.

Ethics, 281; biological, 283; natural, 284; evolution of, 285.

Ethnology, 177.

Evolution, the Doctrine of, 1; is it a science, 3; the conception of, 8; organic, 10-12; 31, 32; evidence of, 54, 95; of amphibia, 62; of birds, 63; of protozoa, 69; theory of, supported by palaeontology, 76; cosmic, 84; biological evidence of, 91; three important elements of, 109; adaptation, variation and inheritance, 110; mechanical, 109; dynamics of, 109; second element of, 122; human, 150-196; 174; physical, of man, falls into two groups, 153; of human races, 176; racial, 177, 178; mental, 197-240; human faculty as a product of, 212; mental as real as physical, 214; of brain, 214-217; of art of writing, 223; method of mental, 231; social, 241; of societies of insects, 258; human, biological interpretation of, 267-274; of higher human life, 278-311; of ethics, 285; final conception of, 307-311.

Factors, primary, secondary, 110; three kinds, 111; congenital, 113.

Falls of St. Anthony, 86.

Fishes, lowest among common vertebrates, 46; trunk-fish, cow-fish, puff-fish, mouse-fish, flounder, 46; most primitive backboned animals, 92; 94; 157; embryos of, 171.

Fiske, 139.

Flies, may, 259.

Flounder, a variant of the fish theme, 66.

Fossilization, conditions of, 77-78.

Fossils, 73-105; remains of, 73; groups, 77; 78, 79; order of succession, 91; oldest rocks devoid of, 92; forms, 99.

Fowl, game cock, 138; pigeons, 138.

Frog, 45; eggs of, larva, development of, 58, 59, 60, 68.

Galapagos Islands, 102, 103, 104.

Galton, 142, 147; heredity of mental qualities, 232.

Gametes, 252.

Gastrula, 68.

Gemmules, 143.

Genera, 32.

Generation, spontaneous, 78.

Geographical distribution, 32.

Geological agencies, rain, rivers, glaciers, 88; construction, volcanoes, 88.

Geology, data of, 83, 84.

Germ, Bonnet's idea of, 70; cells, 144, 146; plasm, 145, 146.

Gibbon, 163.

Gills, 58, 62.

Gill-slits, bars, clefts, 61, 62, 64; in embryos of lizards, birds, mammals, 69; 171.

Giraffe, 133.

Glaciers, alterations made by, 87.

Goats, 157.

Gorilla, 163, 165, 195.

Grand Canon of the Colorado, 85, 90.

Gravitation, 155.

Guinea-pigs, Brown-Sequard's, 148.

Gulick, 103.

Haeckel, 63, 71, 184.

Haemoglobin, 22.

Hapalidae, 160.

Harvey, 70.

Hawaiian Islands, 103; snails of, 104.

Heredity, 142; a real human process, 175; instinct determined by, 206; Anglo-Saxon, 213; of mental qualities, 232.

Heron, 44.

Hesperornis, 99.

Hippopotamus, 42.

Hominidae, 160.

Homo sapiens, 183.

Hoofed animals, 95, 96, 97.

Hornets, communities of, larvae of, 260.

Horse, 41, 42, 65; place of in zooelogical science, 95, 96; development of, 97; perfection of one type of, 136, 157; 167; intelligence of, 209.

House-fly, eggs of, 67.

Human faculty, 212; its three constituents, 212.

Huxley, 6, 26, 30, 63, 184.

Hydra, 50, 51, 52, 53, 68, 69; comparative study of, 204, 205, 206; 254; cells of, 255; 256, 257, 258, 261, 262, 263, 265, 266.

Hydrogen, 25, 27.

Hyracotherium, 96.

Ichthyornis, 99.

Ichthyosaurus, 94.

Indians, American, pictography of, 223, 224; of Brazil, 227; life of, 272.

Individual development, a resume of history of species, 63.

Inertia, 155.

Infant, human, activities of, 216.

Ingestive structures, 17.

Inheritance, 110, 131; biological laws of, 142; paternal and maternal basis of, 144; 145; Mendelian phenomena of, 146; Galton's Law of, 147; laws of, in mental phenomena, 203; strength of, in mental traits, 232; physical, provides mechanism of intellect, 233.

Insects, butterflies, beetles, bees, grasshoppers, spiders, scorpions, 49; 66; eggs of common house-fly, 67; 82; nervous mechanism of, 205; communities of, 207, 258-260, 267; nervous system of, 256, 257.

Instinct, determined by heredity, 206; of higher animals, 208; differs from intelligence in degree, 210.

Intelligence, 203; in mental life of communal insects, 207.

Invertebrates, lower animals devoid of backbone, 47; structural plan, 48; branches of, 49; groups, two layer animals, 50; hydra, sea-anemones, soft-polyps, 50; more complicated, 68; palaeontological materials, 82; evolution of lowest members, 92.

Jaguar, 101.

Jastrow, 294.

Java, 173.

Jellyfish, 81.

Jordan, David Starr, 123.

Kangaroo, 42.

Keane, 185.

Lamarck, 115, 133, 135.

Lampreys, 156.

Language, most important single possession of mankind, 218.

Laplace, 29.

Larvae, of lobster, 66; of insects, 67; of ground wasp, 207; of caterpillar, 259; of wasps, 260.

Lavoisier, 29.

Law of Recapitulation, 66; stated by Von Baer and Haeckel, 71.

Lemurs, 158, 160, 161, 195.

Life, what is it? 27.

Limestone, 89, 90.

Links, 99.

Linnaeus, 79, 158, 183.

Lions, 101; environment of, 112.

Lizard, nearest form to remote ancestor, 45.

Lobsters, 66; larvae of, 66.

Lyell, 80, 107, 135, 136.

MacDougal, 148.

Madagascar, 161.

Mallock, 295.

Malthus, 136.

Mammalia, lower orders of, 42; their own mode of growing up, 64; embryos of, 64; 97; members of class differ, 157, 158; 200; order of mentality, 203.

Mammals, 40, 43, 157; embryo of, 171.

Mammoth, 97.

Marmosets, 161.

Marquesas, 103.

Marsupials, 104.

Mastodon, 97.

Mechanism, organic, 14; living, 110.

Melanesia, 103.

Mendel, Gregor, 145; his law, 146; 147, 148.

Mentality, human, 233.

Metazoa, 254.

Mice, 41, 134; field, 139.

Miller, 293.

Mind, anatomy of, 202; human, differs only in degree, 203; 210, 211; embryology of, 214; palaeontology of, 217; and matter inseparable, 234-237.

Missing links, 77.

Moeritherium, a significant fossil, 97.

Molecule, protein, 22, 23, 24.

Mollusks, 81, 82; connecting widely separated ages, 95.

Monkeys, 158.

Morgan, Lloyd, 148.

Morphology, 32.

Moths, 67.

Mueller, 293.

Mutation theory, 146.

Naegeli, 143, 148.

Natural Selection, doctrine of, 116, 117, 118; the struggle for existence, 124, 125; simply trial and error, 131; Darwin recognized it as incomplete, 142; germ-plasm theory supplements, 145.

Nebula, gaseous, 84.

Nervous systems, 201, 202, 205, 206, 211; of worker-bee, 232.

Niagara, 85, 86, 89.

Ontogeny, recapitulates phylogeny, 63.

Orang-outang, 163, 164.

Orders, 32.

Organic, 15; systems, 17; transformation, analogies of, 43, a real and natural process, 55, 56, 76; mechanism, alteration of, 55.

Organisms, living, 14; analysis of, 16; 17, 18, 19, 26, 28, 29, 31, 32; characteristic early stages, 55; are they adapted by circumstances? 109; environment, 111; physical heritage of, 113; variation of, 119; difference, 121; universal conflict of, 127; change, 130; human, 32, 156, 159, 165-171; nervous system of, 201; psychical characteristics of, 202; many-celled, 257.

Organs, 16, 17, 28; of human body, 156.

Origin of Species, 136, 149.

Origination of new parts, 109.

Osborn, 148.

Ostrich, 44.

Over production, 122-124, 129.

Owls, horned, of Arizona, 45; 139.

Palaeontology, 32, 34, 73, 74, 76; evidence of, not complete, 80, 81; table of facts of, 91; 94; second division of evidence, 95; does it throw light on antiquity of man? 155; of mind, 202, 203, 217.

Paludina, 95.

Partulae, 103.

Pearson, Karl, 6, 7, 142, 147; heredity of mental qualities, 232.

Penguin, a counterpart of the seal, 44.

Peoples, fusion of, 178, 179; Mexicans, 178, 181; Anglo-Saxon, 179; American, 179; Indians, 181, 183, 185, 191, 192; Patagonian, 180, 192; Polynesian, 181, 182, 187; Moor, 181; Zulu, 181, 183; Malay, 181, 183, 190; Mongolian, 181, 186-190; Papuan, 182; Negro, African, Ethiopian, 182, 183, 192-195; Caucasian, 182, 185-189, 195; Veddahs, 182, 188; European, 183; Asiatic, 183; Laplander, 183, 190; Scandinavian types, Norwegians, Swedes, Danes, Germans—north and south—186, 187; types of, 186-196; Persians, 186, eastern, 187; Afghans, Hindus, 186; Welsh, French, Swiss, 187; Russians, 187-190; Poles, Armenians, 187; Mediterranean type, Spaniard, Italian, Greek, Arab, 187; subordinate group, Semitic, Arab, Hebrew, 187; North African, Berber, Hamites, 187; relatives of the Mediterranean, Dravidas, Todas, Veddahs, Ainus, 188; Manchurian, Chukchi, Buryats, Yukaghir, 189; Finlander, Bulgar, Magyar, Korean, Japanese, Gurkhas, Burmans, Annams, Cochin Chinese, Tagals, Bisayans, Hovars, 190; Pueblos, Eskimos, Aztecs, Mayas, Caribs, 191; Yahgan, Alacaluf, 191; Papuan, Australian, 193; Negrito section, Adamans, Kalangs, Sakais AEtas, Bushmen, Hottentots, Akkas, 194.

Periods, Triassic, Jurassic, 94; Eocene, Miocene, 96.

Phenacodus, 96.

Phyla, 32.

Phylogeny, 63.

Pictography, 223-226; of Eskimos, of American Indians, 223, 224; of Asia, 224; of Egypt, 224, 225.

Pig, 42, 157.

Pithecanthropus, 174.

Plesiosaurus, 94.

Polynesia, 103, 104.

Pouched animals, kangaroo, opossums, 42.

Primates, name given by Linnaeus, 158; eutheria, 158, 159; order of, 160; anthropoids, 161; arrangement of organs, 201.

Processes, psychological, of higher animals, 208, 209.

Prosimii, 160.

Proteins, 22, 23, 24.

Protoplasm, 22-30; the physical basis of life, 143; 144; human, 156; chemicals that make up, 156.

Protozoa, 52, 53, 68, 70; relations of, 126.

Protozooen, 251.

Psychology, comparative, 198; principle of, 199; descriptive, genetic, 202; terms of, 203; human, 210, 211.

Pseudopodia, 52.

Puma, 101.

Pupa, 259.

Pygmy, 195, 196, 227.

Rabbits, 41, 101; domesticated, 137; introduced into Australia, 140.

Races, human, age of, 178; divisions of, 183-195; character of: status, variations of, 180, 181; color, a criterion of racial relationship, 181, 184; hair, character of, as means of classification, 181, 182; cranium, shape of, as means of identification, nose, jaws, 182.

Racoon, 38.

Rats, 41, 134.

Reason, 203; in mental life of communal insects, 207.

Religions, 288; Christian, Hebrew, Buddhistic, Tangaroan, 289, 290; Mohammedan, 290, 298; Dervish, Mahdist, 293; linguistic basis of, 293, 294; of savagery, 294, 300, 301; barbarism, civilization, 294; elements of, 295; forms of Christianity, 296; sects, Judaism, 297, 298; Brahmanism, Buddhism, 298, 299; Polytheism, Roman, 300.

Reptiles, variations about a central theme, 45; lizard, typical, 46; 157; embryos of, 171; 200.

Retention of better invention, 109.

Rhinoceros, 41.

Rivers, Mississippi, 86, 89; Hoang-ho, Ganges, Thames, 87; alterations made by, 87.

Rocks, crystalline or plutonic: sedimentary, 85; eruptive, 88; new, 59; of Grand Canon, 90; testimony of, establishes evolution, 100.

Salamanders, 45, 46.

Salts, of sodium, chlorine, magnesium, potassium, 24.

Samoan Islands, 103.

Sandstone, 90.

Science, what is it? 5, 6; physiological, 14.

Sea anemones, 68.

Sea elephant, 38.

Seals, 38, 39, 40, 209.

Selection, natural, doctrine of, 116, 117, 118; struggle for existence, 124, 125; simply trial and error, 131, 136, artificial, 136, 137, 138; laws of, in mental phenomena, 203.

Sequence, physiological, in training animals, 209; 210.

Series, sedimentary, 84, 90, 92; crystalline or plutonic, 85; Azoic or Archaean, age of, 92.

Shale, 89.

Shark, common, most fundamental form, 46; embryo of, hammerhead; embryos of, 66.

Sheep, 157.

Simiidae, 160, 163.

Skate, embryos of, 66.

Snails, 45; shells of, 95; land snails, 103; Hawaiian and Polynesian, 104.

Society Islands, 103.

Solar system, origin of, 84.

Solomon Islands, 103.

Species, origin of human, 153.

Spencer, Herbert, 8.

Squirrels, evolved from terrestrial rodents, 14; 41; flying, true rodents, 41.

Starch, 24.

Stephenson, 10.

Strata, 88, 89; arranged according to ages, 89; 90; time of formation, 92.

Struggle for existence, 124; intra-specific, 125; three divisions of, 126-129; 139, 174, 175.

Substances, inorganic, 29.

Sugar, 23, 24.

Survival of the fittest, 129.

Systems, respiratory, excretory, circulatory, 17; organic, reproductive, 18; nervous, 256, 257; blood-vascular, respiratory and excretory, 257; ethical, 286; religious, 288.

Tadpole, 58, 59, 60; larvae, 64.

Tapeworm, a relative of simple worms, 50; 123.

Tapir, 41; Moeritherium, 97.

Thorndike, 209; heredity of mental qualities, 232.

Tidal waves, 85.

Tigers, 101.

Tirawa, 301.

Tissue-cells, 28.

Torga, 183.

Tortoise, soft shelled, of the Mississippi, 45.

Tower, 148.

Transformation, natural, 170.

Tribes, 32.

Tuberculosis, bacillus of, 127.

Turtles, evolution of, 45.

Ungulates, 65.

Uniformitarianism, Lyell's doctrine, 80.

Urea, 29.

Ussher, Archbishop, 178.

Variation, 110; causes of, 111; among individuals, 112, 113; fact of difference, phenomenon of, 114; 115, 118, 119, 121, 129; congenital, 138; human, 174; racial, 177; laws of, in mental phenomena, 203; 232.

Vertebrata, 43.

Vertebrates, backboned animals, fishes the lowest order of, 46; principles of relationship, families, tribes, 47; 53-59; great classes originate together, 64; more complicated, 68; skeleton remains of, succeed invertebrates, 92; testimony of the rocks, 93; largest, 94; appearance of great classes of, 94; 95; classes that make up, 156; lower, arrangement of organs, 201; nervous system of, 256, 257.