EXPLANATORY Sotminor. This department is as yet in a very incomplete state of development. So far as the physical side of social evolution is coneerned, it exhibits the same phenomena of integration, differentiation, and increasing defi niteness of organization, that material bodies undergo. The cause also is the same, namely the equilibration of energy between bodies over charged and eontignous bodies undercharged. There is such an equilibration between a popula tion and its environment, and all the energy that society is enabled to expend it derives from the bounty of nature, supplemented by industrial activities. There is such an equilibration of energy between strong and weak States and be tween strong and weak races. The transforma tion of the weak by the strong can never cease until equilibrium is established. The transforma tion need not be a. military conquest, however, or even an economic exploitation. So far as physical law is concerned, it may equally well be an uplifting of the weak to higher planes of sympathy and intelligence by the hands of the strong. The extent to which the process may thus he philanthropic depends upon the growth of the consciousness of kind. Originally limited to the kindred of horde and clan, it has broad ened into tribal and at length into a national consciousness. To-day it is becoming a human consciousness. In all this transformation every change obeys the laws of parsimony. :Motion follows the line of least resistance and human activities try to achieve given results with the least expenditure of effort. In is only a corollary of this law that activity is conditioned by the consciousness of kind, since strangeness and an tipathy are resisting conditions. It is only an
other corollary again that dogmatic like-minded ness develops out of sympathetic, and delibera tive like-mindedness out of dogmatic; for the results achieved by the lower forms of con certed volition, namely the instinctive and the sympathetic, are wastefully accomplished as compared with those achieved by the higher forms. These laws are otherwise formulated as the great laws of diminishing and increasing re turns, long familiar to economic science, but equally true in the realm of social phenomena. \\ hen the lower forms of activity are carried far they begin to yield diminishing returns. When old channels of activity are obstructed energies breakthrough into new channels, and for a time new adjustments yield increasing returns. By these laws we account for the substitution of reason for impulse, of deliberation for mob-like action. The substitution is in a broad sense a natural selection. Social activities and forms begin unconsciously. In the course of time men, becoming aware of the social relations that have spontaneously developed, try to perfect them. They create institutions and carry out policies.
The unconscious operations of nature now again assert themselves. Some of the products of man's invention, proving useful, and promoting his welfare, survive. Others perish and are for gotten. Those social forms survive which, like organisms successful in the struggle for exist ence, yield on the whole increasing returns of useful conversions of energy.