Abstract

Suppose one has a visual experience as of having hands, and then reasons as follows: I have hands, If I have hands an external world exists; An external world exists. Suppose one’s visual experience gives one defeasible perceptual warrant, or justification, to believe – that is, one’s experience makes it epistemically appropriate to believe . And suppose one comes to believe on the basis of this visual experience. The conditional premise is knowable a priori. And can be established by modus ponens inference. If one reasons thus, say one’s engaged in -reasoning. What, if anything, is wrong with -reasoning? I consider two prominent responses to this question – the dogmatists’ and Crispin Wright’s. Each finds fault in -reasoning, but on different grounds. I argue Wright’s response faces a problem which is standardly only taken to be faced by dogmatists