Peirce believed that inquiry involves three types of reasoning—abduction, deduction, and induction. While Peirce’s beliefs about reasoning, especially abduction, changed over time, in his mature work the following picture of reasoning emerges: abduction generates and chooses hypotheses to test; deduction determines the entailments of a hypothesis; induction ascertains whether the evidence accords with the hypothesis in question.1 Peirce both identified abduction and coined the word.2 His concept of abduction is one of the most original contributions he made to the study (...) of reasoning. It is also one of the most poorly understood. Peirce’s concept of abduction has been distorted by contemporary... (shrink)

Douglas N. Walton considers the question of whether the conventions of informal conversation can be articulated more precisely than they are at present. Specifically, he addresses the problem of the fallacy of ad hominem argumentation as it occurs in natural settings. Can rules be formulated to determine if criticisms of apparent hypocrisy in an argument are defensible or refutable? Walton suggests that they can, and ultimately defends the thesis that ad hominem reasoning is not fallacious per se. He carries his (...) analysis to the core of action--theoretic reasoning--by examining a number of specimen arguments. As suggested by the title, the conclusion of ad hominem argument is demonstrated to be relative to the arguer's position. In the appendixes of the book, articles by Gerald McAuliffe and Gordon R. Lowe illustrate vivid and powerful cases in which Walton's contentions are put to the test. (shrink)