The incomprehensibleness of the Divine perfections is no reasonable objection against their reality. We do not comprehend the manner even of our own existence, although we are quite certain that we do exist. Assent, however, has often been refused to _a priori_ theistic argumentation, not on the ground that it is illogical, but on the ground that the conclusions inferred are incomprehensible. Thus the author of whom I have just been speaking urges in favour of the procedure which he adopts the following argument, in addition to the one already specified: "Self-existence necessarily means existence without a beginning; and to form a conception of self-existence is to form a conception of existence without a beginning. Now by no mental effort can we do this. To conceive existence through infinite past-time, implies the conception of infinite past-time, which is an impossibility." "Those who cannot conceive a self-existent universe, and who therefore assume a creator as the source of the universe, take for granted that they can conceive a self-existent creator. The mystery which they recognise in this great fact surrounding them on every side, they transfer to an alleged source of this great fact, and then suppose that they have solved the mystery. But they delude themselves. Self-existence is rigorously inconceivable; and this holds true whatever be the nature of the object of which it is predicated. Whoever agrees that the atheistic hypothesis is untenable because it involves the impossible idea of self-existence, must perforce admit that the theistic hypothesis is untenable if it contains the same impossible idea."