Dianoetic Education in Plato’s Republic

In Plato’s Republic, Socrates contrasts dianoetic reasoning to dialectic, his preferred method of inquiry and demonstration. Though dianoetic is unable to yield knowledge, when practiced correctly it may serve as a “prelude” to dialectic. Socrates adopts the dianoetic method in his use of the city/soul analogy to investigate justice and its effects on the soul in Books 2–4 and 8–9. Significantly, conclusions from these arguments have had great influence on interpreters of Plato’s political and moral philosophy in the Republic. Here, I argue that the dianoetic status of Socrates’ investigation has implications for how we should read the dialogue: Socrates’ conclusions should be considered not as stopping points but as road signs in guiding us to the dialectical path. I support this thesis by (1) explaining dianoetic reasoning and contrasting its correct and incorrect use, (2) drawing parallels between the correct use of dianoetic reasoning and Socrates’ use of the city/soul analogy in the Republic, and (3) showing how this dianoetic investigation may serve as a prelude to dialectic for the reader.