In a crucial passage in the Republic found within a discussion of women’s role in the ideal polis, division of eidē is identified as necessary for dialectic. A careful consideration of the way division is described in this passage reveals that it resembles the procedure of division described in the Phaedrus and the Sophist and that this procedure, when carried out correctly, is central to dialectic according to the Republic and helps set dialectic apart from eristic. Consideration of additional passages (...) in the Republic indicates that division may be employed on different kinds of entities, such as virtues and types of human natures; for according to the argument of the Republic, the correct use of division for the purpose of distinguishing types of human natures or virtues, entities that to the untrained eye may look alike but are distinct by nature, is required for achieving the knowledge philosophers and philosopher-rulers need. In fact, correctly performed divisions help the dialectician to bring into focus a subject matter under consideration in a kind of double-vision that reveals that matter as a concrete phenomenon that exhibits participation in different eidê when it is considered from different points of view. (shrink)

This paper considers the use that Plato makes of the Principle of Non-Contradiction in his engagements with eristic refutations. By examining Plato’s use of the principle in his most detailed engagements with eristic—in the Sophist, the discussion of “agonistic” argumentation in the Theaetetus, and especially the Euthydemus—I aim to show that the pressure exerted on Plato by eristic refutations played a crucial role in his development of the PNC, and that the principle provided him with a much more sophisticated means (...) of demarcating philosophical argumentation from eristic than he is generally thought to have. In particular, I argue that Plato’s qualified formulation of the PNC restricts the class of genuine contradictions in such a way that reveals the contradictions that eristics produce through their refutations to be merely apparent and that Plato consistently appeals to his qualified conception of genuine contradiction in his encounters with eristics in order to demonstrate that their refutations are merely apparent. The paper concludes by suggesting that the conception of genuine contradiction afforded by the PNC did not just provide Plato with a way of demarcating genuine from eristic refutations, but also with an answer to substantive philosophical challenges that eristics raised through their refutations. (shrink)

This paper argues that there are three distinct senses of possibility at play in the Republic’s discussion of whether the best city is possible: natural possibility, possibility for existing cities, and ideal possibility. It is argued that Socrates makes different claims about each of the three political proposals in Book v. (1) Women guardians are argued to be naturally possible. (2) Socrates considers it an open question whether the common family of guardians (the so-called ‘community of women and children’) is (...) naturally possible. He argues, however, that it is ideally possible. (3) The philosopher-king is claimed to be possible in the strongest sense: it is not only naturally possible, it is also possible for existing cities. It is for this reason that the common family of guardians is ideally possible. This clarifies the sense in which the best city is best. (shrink)