Kant’s moral argument for faith in God aims not at converting unbelievers but at offering those who believe a reason for principled assent to the existence of God on moral grounds. It is based on a rational connection between purposive action and assent that applies not only to religious belief but to many other purposes as well, such as what Royce called “loyalty to a lost cause.” The argument in the Critique of Pure Reason differs significantly from its presentation in later works. Kantian moral faith is in tension with Cliffordian evidentialism but not inconsistent with it, and the two together constitute the doxastic virtue lying between the twin vices of uncritical credulity and stubborn incredulity; together they enable us to avoid the complacencies of both despairing resignation and overconfidence.