When such a process is caused by some energy impulse from without, it may produce various results. In the simplest case it discharges the corresponding reaction, just as the leaves of the sensitive plant close when they are touched. Or it may give rise to a series of processes following one another like the instinctive actions. Or, finally, it may bring about a series of inner processes which lead to an extreme differentiation of slight differences of this stimulus and to a corresponding graded reaction with the anticipation of success. We call this conscious thinking, willing, and acting. Through the age-long effect of the blunder committed by Plato in making a fundamental distinction between mental life and physical life, we experience the utmost difficulty in habituating ourselves to the thought of the regular connection between the simplest physiological and the highest intellectual acts. Moreover, this contrast has been accentuated by the mechanical hypothesis. If we abandon the mechanical hypothesis and adhere to the summarization of experience free from all hypotheses, as represented in the science of energy, this contrast disappears. For even if we concede the impossibility of conceiving thought as _mechanical_, there is no difficulty in conceiving of it as _energetic_, especially since we know that mental work is connected with expenditure of energy and exhaustion just as physical work is. However, the elucidation of this subject lies almost entirely in the future since the idea just developed has but only begun to influence scientific work in this field. But judging from the results that have already been obtained we may hope for a speedy development. =58. Society.= The external circumstance that as an organism multiplies the new being must come to life in the proximity of the older one, is in itself cause for the formation of closed groups confined to certain localities by animal organisms of the same species. But they become scattered if the advantage of their living together is not such as to outweigh the disadvantage of having a narrow field of competition for the means of sustenance. Thus we see different plants and animals behaving differently in this respect. While some species live in as great isolation as possible, others form communities, even if there is no mechanical tie to hold them together by a common integument. Since the second case is true of man in a highly marked degree, his _social_ characteristics and needs form a large and important part of his life. And since, further, the socialization of man makes continuous headway with increasing civilization--we need but think of the development of the former little groups and tribes into states and the present very active internationalization of the most important affairs of mankind, especially of the sciences--the social problems also occupy an ever larger place in the organization of human life.