Refutation, Deduction and The Demarcation of Philosophy from Sophistry

Abstract

This dissertation argues that Plato’s and Aristotle’s conceptions of genuine philosophical argumentation were significantly shaped by their attempts to distance their own methods from the argumentative practices of the Eristic sophists. The Eristics characteristically employed short question-and-answer refutational arguments in which a questioner deduced a conclusion based on an answerer’s commitments that contradicted one of the answerer’s central philosophical positions, but did so in ways that we would now regard as fallacious. I begin by showing that the Eristics’ refutations presented a significant challenge to Plato and Aristotle not only because they derived contradictions based on important Platonic and Aristotelian commitments, but also because the Eristics’ primary aim in offering these refutations was to establish controversial doctrines that were immune to the contradictions that they derived. In the remaining chapters I argue that Plato originally developed his conception of a genuine contradiction in explicit contrast to the contradictions produced in Eristic refutations and that Aristotle developed his conception of a deduction in direct opposition to the ways in which Eristics deduced contradictory conclusions in their refutations. Plato made it a necessary condition for a refutation that the contradiction it produces satisfy conditions that clearly demarcate genuine contradictions from the merely apparent ones that the Eristics produced. Aristotle then accepted and strengthened Plato’s conception of true refutation by making it a necessary condition for a refutation that its conclusion is deduced in accordance with a set of requirements that clearly exclude Eristic ways of deducing from the class of genuine deductions. These logical innovations provided both philosophers with the tools necessary to diagnose sophistical refutations as fallacies, and thereby to resist the unpalatable doctrines the Eristics advanced through their arguments. On the account I offer, it was in large part through their efforts to demarcate their argumentation from that of these opponents that Plato laid the groundwork for, and Aristotle brought to completion, the first system of logic in Western philosophy.