The Scope of Aristotle's Defense of the Principle of Non-Contradiction

Abstract

In 'Metaphysics' book 4 Aristotle offers several arguments in defense of the principle of noncontradiction (PNC). In this paper I want to focus on the stretch of argument from 1006a11 to 1006b34 which Aristotle calls a proof by refutation (elenktikos apodeixai), (1006a11). Contrary to Elizabeth Anscombe and others, I will argue that in this section of the defense Aristotle can defend a version of the principle that extends to nonessential predication, predication of properties, aggregates, and transcategorials.