Abstract

It is commonly thought that we depend fundamentally on the “evidence of the senses” for our empicial beliefs, including and most directly, our beliefs about our local environment, the spatial world around us. The ultimate evidence we have for our perceptual beliefs is provided in some way by perception or perceptual experience. But what is this evidence? There seem to be three main options: external factualism allows that the evidence include facts about the external world; internal factualism takes facts that involve only the internal, mental world—like facts about one’s perceptual experiences or appearances—to count as one’s perceptual evidence; and non-factualism takes propositions, including false ones, to count as evidence—for example, propositional contents of appearances or seemings. We shall see that all these options face significant challenges. Some might conclude that perceptual beliefs can be justified without depending on evidence. Others might choose to accept skepticism: our perceptual beliefs are not justified. I shall end, however, by tentatively suggesting that there is a sort of internal fact that is a plausible candidate for perceptual evidence that has been overlooked.