Abstract
According to metaphysical realism, there may be features of reality which we cannot conceive. If this thesis of cognitive closure is inconsistent, then, pace dialetheism, metaphysical realism proves incoherent. Recently, Graham Priest has revived Berkeley's idealist argument meant to show that cognitive closure is inconsistent. If cogent, this argument poses a threat to metaphysical realism. I argue that while Priest's reconstruction of Berkeley's argument may be seen to be paradoxical on one interpretation of ‘conceive’, that interpretation is not the intended one. On the intended interpretation, the argument fails and hence leaves metaphysical realism unassailed.