Doubtless the hypothesis of Theism, as thus presented, will be deemed by many persons but of very slender probability. I am not, however, concerned with whatever character of probability it may be supposed to exhibit. I am merely engaged in carefully presenting the only hypothesis which can be presented, if the theory as to an Intelligent Author of nature is any longer to be maintained on grounds of a rational teleology. No doubt, scientifically considered, the hypothesis in question is purely gratuitous; for, so far as the light of science can penetrate, there is no need of any such hypothesis at all. Thus it may well seem, at first sight, that no hypothesis could well have less to recommend it; and, so far as the presentation has yet gone, it is therefore fully legitimate for an atheist to reply:--'All that this so-called metaphysical theory amounts to is a wholly gratuitous assumption. No doubt it is always difficult, and usually impossible, logically or unequivocally to prove a negative. If my adversary chose to imagine that nature is presided over by a demon with horns and hoofs, or by a dragon with claws and tail, I should be as unable to disprove this his supposed theory as I am now unable to disprove his actual theory. But in all cases reasonable men ought to be guided in their beliefs by such positive evidence as is available; and if, as in the present case, the alternative belief is wholly gratuitous--adopted not only without any evidence, but against all that great body of evidence which the sum-total of science supplies--surely we ought not to hesitate for one moment in the choice of our creed?' Now all this is quite sound in principle, provided only that the metaphysical theory of Theism _is_ wholly gratuitous, in the sense of being utterly destitute of evidential support. That it is destitute of all _scientific_ support, we have already and repeatedly seen; but the question remains as to whether it is similarly destitute of _metaphysical_ support.