In “The Uses of Argument” Toulmin introduces a number of concepts that have become popular in argumentation theory, such as data, claim, warrant, backing, force, field, and, most fundamentally, the concept of a “logical type”. Toulmin never defines the concept of a logical type or a field very clearly, and different interpretations can be found in the literature, either reconstructing what Toulmin has in mind, or revising his concepts to suit other concerns. A natural history of these concepts is not (...) my concern. I will analyse logical types according to what Toulmin uses this concept for, namely to raise a problem with deductive logic and motivate its replacement with the Toulmin model. I will argue that a logical type and the distinction he draws between different logical types resembles distinctions made in logical positivism between the directly and the indirectly verifiable, and the problem raised is, in essence, the positivist’s problem of how indirect propositions can be justified on the basis of direct propositions. I will show that Toulmin makes a straw man of the positivists’ own solution to the problem and hence does not prove there to be an adequate motivation for replacing deductive logic with the Toulmin model. (shrink)

This article provides a brief selective overview and discussion of recent research into natural language argumentation that may inform the study of human reasoning on the assumption that an episode of argumentation issues an invitation to accept a corresponding inference. As this research shows, arguers typically seek to establish new consequences based on prior information. And they typically do so vis-à-vis a real or an imagined opponent, or an opponent-position, in ways that remain sensitive to considerations of context, audiences, and (...) goals. Deductively valid inferences remain a limiting case of such reasoning. In view of these insights, it may appear less surprising that allegedly “irrational” behavior can regularly be produced in experimental settings that expose subjects to standardized reasoning tasks. (shrink)