Rhetoric, Dialectic and Syllogistic Argument: Aristotle's Position in "Rhetoric" I-II

Abstract

In Rhetoric I-II Aristotle analyses the kind of reasoning used by orators. He suggests that rhetoric, the art of persuasion, has certain affinities with dialectic, the art of dispute. He also analyses how rhetorical reasoning falls short of the syllogistic reasoning which he explores at length in the Prior Analytics. The relationship of rhetoric to dialectic and to syllogistic argument is complex and difficult. In this paper I shall argue that Aristotle was himself unclear about this relationship, and that his lack of clarity explains certain obscurities in the Rhetoric which have troubled the commentators. The first point to consider is what does Aristotle mean by 'dialectic'. He expounds the method of dialectic in the Topics, which is a list of rules for debating exercises. The Greek term t67r6n literally means 'places', but Aristotle uses it in a logical context to mean something like 'grounds for argument'. He identifies '6rcog with =GoLxeLov in Rhet. 1396 b 20-21, and says in Met. B.2.998 a 25-7 and A.3. 1014 a 35 b 1 that a arotyeZov is a proposition whose demonstration is presupposed in the demonstration of other propositions. So a =odXLov or T67tog is a proposition whose truth is taken for granted in a number of arguments. (Cf. also a remark in Rhet. 1403 a 17-18: g,'L yocp CoOLX?LoV xXol 'r64oc et; 8n E?u that parallel lines do not meet; this proposition is the foundation on which all subsequent theorems are based. In the Topics, the Sr6not are grouped into four principal classes corresponding to the four kinds of predicables, namely, accident, genus, necessary property and definition. In order to use the '6mOL, one must be able to apply the doctrine of the predicables. For example, under the heading of 'accident' Aristotle includes the topic of asserting a predicate to be an accident when it is not really an accident (Top. II.2.109 a 34-5: Etq lkev 8& t6no; '6 ip,XCnetv et cT xa'&XXov 'vTWX -rpo67ov urapXov k mlipepBqx6g hr0oWcoxev). Thus if someone argues that justice is good in some circumstances but not in others, one method of refuting him is to show that justice is always and invariably good (i.e. that goodness is a necessary property of justice, not an accidental one).