The poetic account of human nature cannot possibly be as defective as Socrates presents it. But the great power of poetry requires that it be placed under the jurisdiction of the philosophers for the good of the city. If we think this through, it leads to the subordination of philosophy to justice, and hence to politics. In order to found and live within the just city, philosophers must suppress the poetical side of their nature, or what comes to the same thing, submit it to constant censorship and the degradation of poetry into political ideology. It is no empty paradox to say that the price of entrance for genuine philosophers into the just city is expulsion or purgation of their previous decadent selves.
Plato's Republic: A Study (2005) - Introduction