The Ontological Argument
This chapter argues that Kant’s criticism of the ontological argument is targeted, in the first instance, at Leibniz’s sympathetic revamping of the Cartesian argument. But Kant’s discussion actually contains a suite of objections to the ontological argument, some of them effective against Descartes, others (less successfully) directed against Wolff and Baumgarten, and one—the famous objection that being is not a real predicate—directed exclusively against Leibniz. It argues that this last objection, which appeals to the example of a hundred thalers, succeeds against Leibniz because he is prevented by his stance on the Euthyphro contrast from offering the obvious reply. Kant’s most famous objection is thus an ‘ad hominem’ argument in the original (and now largely forgotten) sense of that term: a perfectly rational argument that does not attack an opponent’s character, but rather uses one of their own commitments against them.