Metaphysics and the Vera Causa Ideal: The Nun’s Priest’s Tale

Abstract

L.A. Paul has recently defended the methodology of metaphysics on the grounds that it is continuous with the sciences. She claims that both scientists and metaphysicians use inference to the best explanation (IBE) to choose between competing theories, and that the success of science vindicates the use of IBE in metaphysics. Specifically, the success of science shows that the theoretical virtues are truth-conducive. I challenge Paul’s claims on two grounds. First, I argue that, at least in biology, scientists adhere to the vera causa ideal, which allows the theoretical virtues to play a much more limited role in scientific reasoning than Paul requires for metaphysical reasoning. The success of biology thus does not vindicate the methodology of metaphysics. Second, I argue that, at least in many cases, the successful reliance on the theoretical virtues in scientific contexts shows only that the theoretical virtues are truth-conducive within those local contexts, and not that they are truth-conducive generally. The upshots are (1) that Paul’s defense of the methodology of metaphysics fails, and (2) that any attempt to rescue her defense must pay more careful attention to what precisely is vindicated by successful science.