In Metaphysics IV, Aristotle offers his defense of what is known as the principle of non-contradiction (PNC). While he initially defines the principle ontologically in terms of objects and their properties -(Fx and -Fx), many commentators have held that Aristotle is also defending the modern logical version of PNC which governs propositions and their truth values, -(p and -p). In my paper, I will argue that such an interpretation is misguided. While a logical variant of the principle does appear in the late stages of Aristotle’s defense, it is not the modern logi­cal version. Moreover, if we read Aristotle as defending the modern logical version, he runs the risk of begging the question (petitio principii) at three different junctures in his elentic proof. In contrast, if we read Aristotle as defending the ontological version of the principle, we can make better sense of Aristotle’s willingness to use logical argumentation in his defense and ul­timately save him from a petitio principii.

ORT: Sitzungssaal des Katholisch-Theologischen Dekanates, Uni Wien, Hauptgebäude, 2.Stock, über der Universitätsbibliothek (UB)

ZEIT: Do, 10. Jan. 2008, 18:30 Uhr s.t.

Eintritt: frei