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 palæontological 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.