INTRODUCTION.

• Author: Leff, Michael C.
• Position: Review

During the winter of 1999, Douglas Walton visited Northwestern University as a Fulbright Senior Fellow and taught a seminar in the Department of Communication Studies. The seminar, attended by Northwestern faculty as well as graduate students, offered an important opportunity to compare and combine two approaches to argumentation that have proceeded along similar but largely independent lines--American studies of the rhetoric of argument and Canadian informal logic. The papers collected in this issue are products of that seminar and represent a concerted effort to bring the two traditions into productive contact with one another.

In the essay that follows, Walton presents a clear summary of his own approach, and for the most part the affinities with rhetoric are so obvious that they require no commentary. Nevertheless, two points deserve special notice. The first is Walton's use of actual public arguments as a basis for generating and testing his theory. Like many other recent students of informal logic, Walton insists that arguments cannot be understood solely in terms of their formal features and thus argumentation theory must ground itself in the practical conduct of argument. More than most of his colleagues, Walton has taken this principle to heart and replaced the standard, abstract, and hypothetical cases of the logic textbooks with complex examples derived from the public arena. In this particular essay, Walton's focal subject is an argument that surfaced during the Clinton impeachment trial-precisely the kind of subject that has traditionally interested American rhetoricians-and the essay also displays sensitivity to such rh etorical considerations as the context of the argument's presentation and the personae of the arguers.

The second point is less obvious but more important, and it has do with Walton's attitude toward ad hominem. Note that he does not consider ad hominem a fallacy, a mistake in reasoning, but a kind of argument. In fact, for Walton, the traditional fallacies become argumentative schemes, and while they may be used fallaciously, they may also constitute legitimate arguments. Walton retains the normative rationality of traditional logic (i.e., the interest in judging whether arguments are or are not sound), but he does not rest his judgments on formal criteria. Appeals to the person of the arguer are not dismissed categorically, but are assessed relative to the purposes and contexts in which arguments appear. This...