One of the most significant figures in the history of Japanese philosophy is the Zen master Hakuin. Yet, in the West, little attempt has been made to present and evaluate his thought in a way that would make it accessible to Western philosophers. This article attempts to redress this neglect. Here, it is shown how Hakuin uses kōan meditation to create ‘the great doubt’ or scepticism concerning the self. Hakuin’s method shares elements in common with both ancient Greek scepticism and Descartes. Kōan-induced scepticism leads to ‘the great death’ or a rejection of the self as a delusion. Hume’s similar rejection of the self helps to explain the basis of this delusion. The rejection of this delusion carries with it the realization that one is not separate from the rest of reality. This is the instant of seeing into one’s own nature and, for Hakuin, is the experience of nirvana.