"The New Rhetoric"'s Argument Schemes: A Rhetorical View of Practical Reasoning.

In a lecture delivered in 1957, Chaim Perelman (1958) described the workings of practical reasoning and compared them to the structures of formal logic: Why envisage proof always in terms of a single model? . . . |A~ final convergence |of a number of indications~ can lead to conclusions so sure that only a lunatic would ever think of doubting them. . . . When we have to reconstruct the past |for example~ the arguments which we use seem to me very much more like a piece of cloth, the total strength of which will always be vastly superior to that of any single thread which enters into its warp and woof. In The New Rhetoric, Perelman and Olbrechts-Tyteca (1969) developed a description of the various threads making up this cloth; these include the starting points for argument, the conventions governing argument practices, and the mechanisms or schemes for making inferences.(1) Each of these dimensions of argument is tied in Perelman and Olbrechts-Tyteca's (1969) theory to a conception of what the arguer believes that the audience will accept, since "it is in terms of an audience that an argumentation develops". For instance, the starting points of argument--facts, truths, presumptions, values, hierarchies, and the loci of the preferable--are derived from premises to which the arguer's anticipated audience presumably subscribes. The conventions for conducting arguments also grow out of practices and norms mutually accepted by interlocutors who participate together in a common culture. Likewise, the inferential schemes that move the audience to accept the arguer's claims are generated through commonplaces and structures recognized and accepted by Western society. Over two-thirds of The New Rhetoric was devoted to describing these agreed-upon liaisons that make inferences possible, for Perelman and Olbrechts-Tyteca believed that in practical reasoning, inferential moves are made possible rhetorically. Yet The New Rhetoric's system of argument schemes has not received attention proportionate to its significance. While numerous studies have focused on the concepts of universal audience (Scult, 1976; Ray, 1978; Perelman, 1984; Golden, 1986), presence (Karon, 1976), and the rationality/reasonableness distinction (McKerrow, 1982; Laughlin & Hughes, 1986), attention to the argument schemes themselves has been infrequent, despite the fact that Perelman and Olbrechts-Tyteca (1969) devoted the bulk of their treatise to the rhetorical nature of inference forms. Quasi-logical, analogical, and dissociative scheme types have been individually studied (Dearin, 1982; Measell, 1985; Schiappa, 1985). One critique of the system has appeared (van Eemeren, Grootendorst, & Kruiger, 1984), and various critics have made partial or tentative efforts to apply the schemes to argument practices (Siebold, McPhee, Poole, Tanita, & Canary, 1981; Farrell, 1986). While argument textbooks make general use of the scheme typology to describe argument practices (Katula, 1983; Herrick, 1991), precise study of the individual schemes has been sporadic and indeterminate. Two decades after The New Rhetoric was published, Olbrechts-Tyteca (1979) expressed disappointment at the lack of attention given to the study of specific schemes. And in 1986, Thomas Farrell could claim that The New Rhetoric's descriptions of practical reasoning practices "have been the singularly most neglected feature of Perelman's rhetorical theory". The scheme typology is nonetheless of singular importance because it provides us with a rhetorical account of the operation of argument schemes. Prior to The New Rhetoric, our vocabulary for describing inference patterns was limited to formal logical patterns (e.g., categorical, disjunctive, and conditional syllogisms) and the standard classifications of inductive reasoning (analogy, generalization, cause, and sign). Perelman and Olbrechts-Tyteca (1969) generated their schemes through a careful empirical process in which they collected discursive arguments for over ten years, typed them, and added new categories (dissociations, symbolic liaisons, and double hierarchy arguments, among others), thus providing a richer vocabulary for describing reasoning structures. …