can decide what the proper concept of virtue is, then the question whether any particular act is virtuous can only be decided by comparing that act with the concept, and seeing if they agree. The Sophist can no longer say, "whatever seems to me right, is right for me. Whatever I choose to do is virtuous for me." His act must be judged, not by {146} his subjective impressions, but by the concept or definition, which is thus an objective standard of truth, independent of the individual. This, then, was the theory of knowledge propounded by Socrates. Knowledge, he said, is not the same thing as the sensations of the individual, which would mean that each individual can name as the truth whatever he pleases. Knowledge means knowledge of things as they objectively are, independently of the individual, and such knowledge is knowledge of the concepts of things. Therefore the philosophizing of Socrates consisted almost exclusively in trying to frame proper concepts. He went about enquiring, "What is virtue?" "What is prudence?" "What is temperance?"--meaning thereby "what are the true concepts or definitions of these things?" In this way he attempted to find a basis for believing in an objectively real truth and an objectively real moral law. His method of forming concepts was by induction. He would take common examples of actions which are universally admitted to be prudent, and would attempt to find the quality which they all have in common, and by virtue of which they are all classed together, and so form the concept of prudence. Then he would bring up fresh examples, and see whether they agreed with the concept so formed. If not, the concept might have to be corrected in the light of the new examples.