Deceptive Arguments Containing Persuasive Language and Persuasive Definitions

Using persuasive definitions and persuasive language generally to put a spin on an argument has often held to be suspicious, if not deceptive or even fallacious. However, if the purpose of a persuasive definition is to persuade, and if rational persuasion can be a legitimate goal, putting forward a persuasive definition can have a legitimate basis in some cases. To clarify this basis, the old subject of definitions is reconfigured into a new dialectical framework in which, it is argued, a definition should be evaluated in light of its purpose as a speech act. But if persuasive definitions are so often thought to be suspect, misleading, or even fallacious, how can individual cases be judged on some objective basis? In this paper, a new dialectical method of evaluating such definitions on a case-by-case basis is proposed, showing how abusive as well as reasonable uses of persuasive language can properly be identified, analyzed and evaluated. The purpose of this project is to develop a new approach to the study of persuasive definitions in different contexts of argumentation. Two more general other concerns also come centrally into the project: the study of definitions generally in argumentation, and the persuasive use of language in argumentation. The new approach to these subjects will show how the use of persuasive definitions should be evaluated by context-dependent sets of rules for argumentative discourse. Such a method of evaluation shows how such definitions can be used for legitimate purposes of persuasion in some cases, and therefore cannot be dismissed or categorically classified as misleading, deceptive or fallacious. Examples of persuasive definitions are presented from ethical disputation, discussions of social policy issues, scientific argumentation, business communications, and legal arguments. The project begins by reviewing Stevenson’s theory of persuasive definition and some real cases that illustrate persuasive definitions at work. The project is interdisciplinary, in that although it has a traditional base in logic, it also draws on recent work in the fields of computing (Reed, 1998; Grasso et al., 2000; Singh, 2000; Bench-Capon, 2002) and communication studies (Perelman and Olbrechts-Tyteca, 1969; van Argumentation (2005) 19:159 186 Springer 2005 DOI 10.1007/s10503-005-2312-y