Argument Schemes and the Evaluation of Presumptive Reasoning

Abstract

In “Presumptive Reasoning/Argument: An Overlooked Class” (Blair 1999) J. A. Blair makes a largely convincing case that “presumptive reasoning/argument represents a sui generis class of reasoning/argument” (Blair 1999, p.15). The strength of Blair’s paper lies in the fact that

• a) he demonstrates through the use of examples that there is a large class of plausible arguments/inferences that don’t fit the usual models of good deductive or of good inductive reasoning

• b) he sets out a list of four properties of presumptive reasoning — properties whose joint presence might be taken to be criterial for the class in question.