=1. The Stoic Psychology.= The Stoic built his conception of personality upon a deep psychological analysis. The soul in the body is like the pneuma in the world (see p. 255). Not only does the soul transform the excitations of the several sense organs into perceptions, but its distinguishing faculty is its power of transforming the excitations of the feelings into acts of will. This was called by the Stoics _the assent of the reason, and is the distinguishing feature of the Stoic conception of personality_. It established for the first time in history the independence of the personal soul. The Stoic felt keenly the antagonism between the reason and the senses, and he also felt that by estimating the senses as merely relative in value they would so much the more dignify the reason as the fundamental feature of the personality. While, therefore, all knowledge comes from the senses, the Stoic maintained that no knowledge exists in the senses by themselves. The assent of the reason is necessary to transform the sensations into true knowledge. The reason is not an aggregate of sensations, but an independent function of the personality. It transforms the sensations into perceptions, the perceptions into acts of will. The reason is therefore a kind of generating power of consciousness and is free from everything external. But in contrast to this free rational side is the irrational nature of man; for the reason is liable to suffer failure, when it allows itself to be hurried along to give assent to exciting causes. Then emotions arise, and emotions are failures, mental disturbances, and in chronic cases diseases. Man is not always able to defend himself against the excitations of his environment, but he can refuse to give the excitations his assent. He can refuse to allow the excitations to become emotions and to pour forth his life in passion. Man may be in the world and not of it. He may govern the world by controlling himself. The Wise Man is free from the emotions, and virtue consists in their absence. The virtuous man is self-sufficient in the proud consciousness that he can look upon pleasure as not a good and pain as not an evil. What guide does the reason have in granting or refusing its assent to its perceptions from without? What is the criterion of the truth? The clearness of the perception――the clearness in the sense that the presentation lays hold of the mind and extorts its assent. The truth is the “irresistible presentation” or the “apprehending presentation.” Who can know the truth? The Wise Man. By what means? By sensation and preconception. By what sign? By the sign of its irresistible power. The Wise Man is perfectly free and perfectly necessitated――he never gives assent except to what constrains assent.