The preface of the Only Possible Ground reveals his inner torment. Providence, he writes there, already imparted to common sense the notion that God exists, hence the project of a demonstration is redundant (2:65). The insight that God exists does not need “the sophistry of subtle inferences” (ibid.). In theory, such a demonstration might illuminate much else in this object, but “to achieve this purpose, however, one must venture into the bottomless abyss of metaphysics” (2:65.25–66.1). And what is metaphysics? A dark ocean without shore and lighthouse, Kant says, on which it is all too easy to lose one’s way (2:66.1–6).