Tommaso Piazza

University of Pavia & LanCog

Second Thoughts on Pollock’s Notion of a Defeater

11 October 2019, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: In this talk I re-examine Pollock’s general characterization of a defeater (DEF), and Chandler 2013’s (until now unchallenged) objection against it. Chandler’s objection takes the form of a dilemma. He presents an example in which it is intuitive that D is a defeater for E as a reason for P, and E is not a defeater for D as a reason for P. On one horn of the dilemma allegedly illustrated by this example, DEF commits to denying that D is a defeater for E as a reason for P. On the other, it commits to saying that E is a defeater for D as a reason for P. Chandler’s objection can be resisted by showing that it presupposes a notion of reason that is different than the notion of reason to which DEF is meant to apply. Then I address the question about whether better examples can be devised that presuppose Pollock’s notion of a reason and illustrate the kind of dilemma Chandler has in mind. I show that standard Gettier cases (and possibly similar cases) provide initially more promising examples; however, on closer inspection they only raise a harmless variant of Chandler’s original dilemma. Thus, I conclude that Pollock’s DEF has not been successfully challenged by Chandler.