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)

In Metaphysics Theta 3 Aristotle attributes to the Megarics and unknown others a notorious modal thesis: (M) something can φ only if it is φ-ing. Aristotle does not tell us what motivated (M). Almost all scholars take Aristotle’s report to indicate that the Megarics defended (M) as a highly counterintuitive doctrine in modal metaphysics. But this reading faces several problems. First: what would motivate the Megarics to hold such a counterintuitive view? The existing literature tries, in various ways, to motivate (...) (M) in a way neither trivial nor absurd. But, as we will argue, the main approaches end up attributing an unsustainable position to the Megarics. Second: most historical evidence for the Megaric lineage presents the group’s philosophical practice as dialectical or negative. So why think that the claim reported in Theta 3 presents a positive, and highly controversial, metaphysical claim? This paper addresses these problems by proposing a dialectical (or negative) reading of the Megarics in Theta 3. By ‘dialectical’ we here mean a mode of philosophizing that neither seeks to establish the truth or falsity of certain theses, nor takes a skeptical stance. There are different reasons why a philosopher might want to take up such a mode; in the case of the Megarics we argue that they might have wanted to put pressure on Aristotle’s idea of possibility and the ‘test’ for possibility that Aristotle mentions in several works. Reading, as we do, (M) as (part of) a paradox about possibility and actuality, we argue that the Megarics’ dialectical approach here aims to highlight a shortcoming of an intuitive conception of possibility, which underpins Aristotle’s idea of possibility and which features in his test for possibility. (shrink)

Bryson of Heraclea and Polyxenus have received little attention from scholars. Sources on these philosophers are few and difficult to interpret. However, they present interesting dialectical arguments that concern some of Plato’s and Aristotle’s most important theoretical elaborations: Bryson’s arguments on the issue of semantic ambiguity were explicitly discussed by Aristotle, and Polyxenus is credited with a particular version of the Third Man argument. My purpose in this paper is to reconstruct the historical background of these two philosophers and to (...) analyze the philosophical implications of the arguments that the ancient tradition ascribes to them. (shrink)

Los últimos cursos de M. Foucault en el Collège de France prestaron especial atención a la noción de parrhesía y su papel en la tragedia y la filosofía griega para revisar los tratamientos sobre el poder y la verdad. Dichos desarrollos pueden ser teóricamente enriquecidos con el estudio de la figura de Alcibíades y su tematización en el entorno del círculo socrático. Este horizonte mostrará la potencia de sugerencias de Foucault poco atendidas que señalan el camino de investigaciones pendientes e (...) iluminan a la vez la antigüedad y la filosofía contemporánea. (shrink)