As a psychologist, Plato is concerned less with the city's political body and organization than he is with shaping the souls of citizens in the city. In this role he considers things like how to "persuade [children] that no citizen was angry with another "(56). Meanwhile, in his other role as political scientist Plato is concerned with structuring of the city's political system to maximize harmony and efficiency. .
The actions and forms of expression that Plato seeks to ban in his role as psychologist are numerous and oftentimes rather obscure, so the reader would do well to focus instead on the less numerous justifications that Plato cites for banning things in his aristocracy. In fact, there are only two arguments that Plato presents over the course of The Republic to justify banning things in the city, but each argument is extremely important in its own right. It should be noted here that Plato's primary function as a de facto psychologist, it seems, is to enumerate what shall be banned from the city as a way to ensure that citizens' souls are shaped in the correct manner. .
Arguably the broadest and more important justification that Plato gives for banning things in his aristocracy is that some things must be banned because they contradict the forms or they are not "holy"" (69). That something would contradict the forms in Plato's city is of utmost importance to him because the forms represent the highest level of knowledge and truth attainable by humans and because this contradiction is potentially destructive to the human soul. Plato is slightly more ambiguous regarding the significance of something in his city that is not "holy ", but he at least makes it clear that holiness is important because of its relation to the gods and to men's souls "that is, "if [the city's] guardians are going to be god-revering and divine insofar as a human can possibly be " (61). And Plato uses these justifications to banish poets and various types of speech from his city.
