• Mackie and Boyle on Self-Refutation

Self-refutation arguments—i.e., arguments to the effect that a certain position is self-refuting—have played a crucial role in the history of philosophy and in metaphysics, and are often held to be a particularly philosophical kind of argument. However, there are considerable disagreements regarding the efficacy of such arguments. J. L. Mackie—in his classic analysis of self-refutation—argues that such arguments do not establish metaphysically necessary conclusions, and thinks that they have been misused by major figures such as Descartes and Berkeley. J. M. Boyle, meanwhile, holds that such arguments play a distinctive role in establishing metaphysical conclusions. This paper comes down on the side of Mackie, arguing that Boyle has gone awry in thinking that the inevitable falsity of a statement implies the necessary falsity of the proposition that that statement expresses. Boyle should instead plump for something like Nor-man Malcolm’s view on ‘mechanism’, viz., that it cannot be coherently or rationally asserted. However, even if self-refutation arguments do not establish the necessary falsity of the opponent’s view, they can nevertheless retain considerable dialectical significance if they can show that the opponent’s view cannot be coherently or rationally asserted.