Abstract

The purpose of this paper is to argue for the necessity of dialectic in Aristotelian philosophy—dialectic defined as the art of arguing from probable opinions to contradictory conclusions. In particular, I will argue that dialectic is necessary for definition. In the Posterior Analytics, Aristotle identifies three principles of scientific demonstration: axioms, un-middled premises, and definitions. In showing the need for dialectic to define, I also show scientific knowledge’s dependence on dialectic.