Naturalism and the Paradox of Revisability

This paper examines the paradox of revisability. This paradox was proposed by Jerrold Katz as a problem for Quinean naturalised epistemology. Katz employs diagonalisation to demonstrate what he takes to be an inconsistency in the constitutive principles of Quine’s epistemology. Specifically, the problem seems to rest with the principle of universal revisability which states that no statement is immune to revision. In this paper it is argued that although there is something odd about employing universal revisability to revise itself, there is nothing paradoxical about this. At least, there is no paradox along the lines suggested by Katz. It is, to say the least, embarrassing when one’s own theory turns out to be self refuting. Indeed, there is no more damning critique of a position than to show that it is either inconsistent or otherwise fails by its own lights . Such was the plight of naïve set theory, naïve truth theory, logical positivism and, arguably, relativism about truth. The problem in each case is that, under diagonalisation, the theory in question leads to paradox. Jerrold Katz (2000) argues that there are similar problems for Quinean naturalism. According to Katz, the three central tenets of Quinean naturalised epistemology taken together are inconsistent. In the next section I examine Katz’s argument. In section 2 I propose a solution to Katz’s puzzle. In the following section I discuss a more formal argument to paradox, and in the final section I suggest that Katz’s argument is self undermining.