We must also recall that the whole scheme, the whole radical subpicture, seems incoherent in a familiar way. One who states and proposes this scheme makes several claims about the Dinge: that they are not in space and time, for example, and more poignantly, that our concepts don't apply to them (applying only to the phenomena), so that we cannot refer to or think about them. But if we really can't think the Dinge, then we can't think them (and can't whistle them either); if we can't think about them, we can't so much as entertain the thought that there are such things. The incoherence is patent.
Would it be possible to induce coherence by refusing to make the distinction between phenomena and noumena, speaking only of what, if we did make that distinction, would be the phenomena, and claiming that whatever there is, is either a bit of experience or an object constructed by us from bits of experience by way of concepts (i.e., rules for constructing things from experience)? That is extremely hard to believe: are the stars, for example, which, as far as we can tell, existed long before we did, either bits of human experience or objects constructed by us from bits of human experience? How are we supposed to make sense of that? On this view, furthermore, the objection to Christian belief would not be that serious Christians improperly take it that they can refer to God; the objection would be that there is no God. If there were such a person, he certainly wouldn't be either a bit of human experience or something we have constructed from it. Still further, on this picture we ourselves (because we are among the things there are) would either have constructed ourselves from bits of experience or we would just be bits of experience; but of course we couldn't have constructed ourselves before we existed, so we must have started off, at least, as bits of experience with the power to construct things. Not a pretty picture. And even if we could somehow induce coherence here, why should we feel obliged to believe it? What possible claim could such a bizarre scheme have on us?
By way of conclusion then: it doesn't look as if there is good reason in Kant or in the neighborhood of Kant for the conclusion that our concepts do not apply to God, so that we cannot think about him. Contemporary theologians and others sometimes complain that contemporary philosophers of religion often write as if they have never read their Kant. Perhaps the reason they write that way, however, is not that they have never read their Kant but rather that they have read him and remain unconvinced. They may be unconvinced that Kant actually claimed that our concepts do not apply to God. Alternatively, they may concede that Kant did claim this, but remain unconvinced that he was right; after all, it is not just a given of the intellectual life that Kant is right. Either way, they don't think Kant gives us reason to hold that we cannot think about God.
Warranted Christian Belief