Republic Bk. IV (cont.) EP 15 The Theory of Parts of the Soul and the Humunculus Problem

If Socrates is to convince Glaucon that justice and injustice in the soul is like justice and injustice in the city-state, then he must prove that there are parts of the soul analogous to the three classes of the city-state. Socrates believes he can do this by using the Principle of Opposites. But having made his point he runs into another question: Is each part of the soul an entity (a "humunclus") that has its own parts?