The ontological argument aims at asserting the possibility of conceiving the idea of an _ens realissimum_, of being possessed of all reality. But the idea of existence and the fact of existence are two very different things. Whatever I conceive, or sensibly imagine, I necessarily conceive as though it were existing. Though my pocket be empty, I may conceive it to contain a "hundred thalers." If I conceive them there, I can only conceive them as actually existing there. But, alas, the fact that I am under this necessity of so conceiving by no means carries with it a necessity that the coins should really be in my pocket. That can only be determined by experience. The cosmological argument contends that if anything exists, there must also exist an absolutely necessary being. Now, at least I myself exist. Hence there exists an absolutely necessary being. The argument coincides with that by which the thesis of the fourth antinomy is supposed. The objections to it are summed up in the proof of the antithesis of the fourth antimony. As soon as we have recognised the true conception of causality, we have already transcended the sensible world. The physico-theological or teleological argument is what is often styled the argument from design. It proceeds not from general, but particular experience. Nature discloses manifold signs of wise intention and harmonious order, and these are held to betoken a divine designer. This argument deserves always to be treated with respect. It is the oldest and clearest of all proofs, and best adapted to convince the reason of the mass of mankind. It animates us in our study of nature. And it were not only a cheerless, but an altogether vain task to attempt to detract from the persuasive authority of this proof. There is nought to urge against its rationality and its utility. All arguments, however, to prove the existence of God must, in order to be theoretically valid, start from specifically and exclusively sensible or phenomenal data, must employ only the conceptions of pure physical science, and must end with demonstrating in sensible experience an object congruous with, or corresponding to, the idea of God. But this requirement cannot be met, for, scientifically speaking, the existence of an absolutely necessary God cannot be either proved or disproved. Hence room is left for faith in any moral proofs that may present themselves to us, apart from science. With this subject ethics, the science of practice or of practical reason, will have to deal. The Critique of Practical Reason