Philosophers, we are reminded, know the Forms and Goodness itself. Artists do not know the Truth. Take the example of the painter and extend it: Suppose the painter wants to paint a picture of a bridle. He has to copy a bridle made by some craftsman, a bridle-maker. The bridle-maker knows more about the bridle than the painter knows. And the bridle-maker made the bridle for some horseman, who knows how he wants the bridle made. And the real bridle is the Form of Bridle. Ergo, the knowledge the painter possesses is thrice removed from reality.
Socrates at this point tries to establish the attractiveness of the visual and dramatic arts, for which argument he adopts a kind of critical process analysis of painting and drama. Socrates points out that we are in everyday existence surrounded by spurious information and illusory experience which only our exercise in reason can correct, and that is precisely what is wrong with the arts: They deal in things illusory, depending upon illusion to accomplish their end. Painters, for example, create the illusion of depth in their works, and they can use line and proportion in the service of the illusion they are trying to accomplish. Any illusion is spurious, contradictory to man's best virtue, reason.
Socrates says that the same fault may be discerned in poets and dramatists, in that they employ language to create unstable tragic and comic characters of men and women who seem to be driven by their emotions and desires, people who lack reason. It is true that some drama and poetry is exciting, but the excitement it provokes is irrational.
