(_a._) _The Ontological proof._—The argument here is as follows: it is possible that there is a most real being; now existence is implied in the conception of all reality, and hence, existence necessarily belongs to the conception of the most real being. But, answers Kant, existence is not at all a reality, or real predicate which can be added to the conception of a thing, but it is the position of a thing with all its properties. A thing, however, may lose its existence, and still be deprived of none of its properties. Hence if it have any property, it does not at all follow that it possesses existence. Being is nothing but the logical copula, which, does not in the least enlarge the content of the subject. A hundred actual dollars, _e. g._ contain no more than a hundred possible ones; there is only a difference between them in reference to my own wealth. Thus the most real being may with perfect propriety be conceived of as the most real, while at the same time it should only be conceived of as possible, and not as actual. It was therefore wholly unnatural, and a simple play of school wit, to take an idea which had been arbitrarily formed, and deduce from it the existence of its corresponding object. Any effort and toil which might be spent upon this famous proof is thus only thrown away, and a man would become no richer in knowledge out of simple ideas than a merchant would increase his property by adding a number of ciphers to the balance of his accounts.
(_b._) _The Cosmological proof._—This, like the ontological, infers the existence of an absolute being from the necessity of existence. If any thing exist there must also exist an absolutely necessary being as its cause. But now there exists at least I myself, and there must hence also exist an absolutely necessary being as my cause. The last cosmological antinomy is here brought in to criticise the argument at this stage. The conclusion is erroneous, because from the phenomenal and the accidental a necessary being above experience is inferred. Moreover, if we allow the conclusion to be valid, it is still no God which it gives us. Hence the farther inference is made: that being can alone be necessary which includes all reality within itself. If now this proposition should be reversed, and the affirmation made that that being which includes all reality is absolutely necessary, then have we again the ontological proof, and the cosmological falls with this. In the cosmological proof, the reason uses the trick of bringing forth as a new argument an old one with a changed dress, that it might seem to have the power of summoning two witnesses.