Unless it is to resemble a voice without a speaker, Christology must pre-suppose a backing in Theism; and any talk of Revelation must assume some conviction, to be more or less rationally defended, of the existence of the God who speaks. Such a Theism, admittedly, can by no means be erected from the bricks of the discursive reason alone; for reason is often, if not always, simply the finding of reasons for what one cannot help but believe by a sort of insight, intuition–or even inspiration. Yet reason, together with the language in which it is bound up, is the common factor which we all share with each other; so that if Theism is to be given a hearing, it must be able publicly to commend itself by the displaying of some reasons, even if (as is the case) those reasons fall short of proof. Such at any rate is my excuse for what follows.