Abstract
There is a Barthian objection to the project of natural validation theology (i.e. to the attempt to establish, on purely natural bases, whether God exists) according to which, far from being required to engage in the project, the theologian is required to abstain from engaging in it. By considering the motivation for an analogous objection to validation projects in metaphysics and epistemology, voiced by representatives of the comman sense tradition in modern Western philosophy, I argue that this objection is plausibly motivated by the thought that engaging in natural validation theology inappropriately commits one to the irrelevance of putatively nonnatural belief-sources.