On Refutations of Skepticism

Abstract

Perception and realism are intimately related topics, for opponents of realism typically base their argument upon certain assumptions drawn from the philosophy of perception. First, a distinction is drawn between what can and cannot be directly perceived; second, the entities and facts whose reality is in question are located beyond the realm of immediate observation; third, all possible ways of inferring the existence of the entities are considered and found wanting; and fourth, it is concluded that we have no reason to believe in their reality. This structure is exemplified by anti-realist arguments in various domains. In this paper I would like to focus mainly on the debate surrounding scientific theories, and then attempt to extract from that discussion some morals for the issue of realism concerning the external world. To begin with, since realismmeans so many different things to different people, let me be quite explicit about the senses that I shall attach to it. I think there are three forms of realism: epistemological, semantic, and metaphysical. By epistemological realism, I mean the doctrine that some specified class of entities exists. Thus one will normally be an epistemological realist about certain things (e.g. electrons, stars) and not about others (e.g. Martian Canals, the Loch Ness monster) depending on whether one does or does not believe in them, and regardless of any view about what their existence would consist in. Epistemological realism concerning X's is opposed both to general philosophical scepticism and also to any non-philosophical reason to question their existence. By semantic realism, I mean the antireductionist, anti-verificationist view to the effect that statements in a certain domainare to be construed literally, at 'face-value', and not to be understood as shorthand for complexes of observation reports or assertions of verifiability. Finally, by metaphysical realism, I have in mind the doctrine that the concept of truth is not entirely captured by Tarski's disquotation schema (P is true iff P), but involves a primitive, non-epistemic idea of correspondence with reality.'