No abstract

Most work in Kant's epistemology focuses on what happens "upstream" from experience, prior to the formation of conscious propositional attitudes. That story is familiar: fi rst there is sensory or pure intuition, then conceptualization in accordance with categorial rules, and, ultimately, cognitive experience that is susceptible to propositional judgment. Precisely how all this works, of course, has been the topic of 225 years of debate. Most work in Kant's epistemology ignores what goes on "downstream" from experience, despite the fact that this aspect of Kant's account touches directly on issues of substantial interest in contemporary philosophy. In particular, commentators neglect Kant's view of what it is for a judgment to be justifi ed or count as knowledge, as well as his account of the principles that ought to guide our practices of judgment formation if the latter are to count as rational. 1 We might well wonder why. One suggestion is that Kant's discussions of this sort of thing-justifi cation and the ethics of belief-are short and sketchy, and, moreover, they're located in the "Canon of Pure I am indebted to the following people for helpful discussions of the ideas in this essay:

Kant's speculativetheistic proof rests on a distinction between "logical" and "real" modality that he developed very early in the pre-critical period. The only way to explain facts about real possibility, according to Kant, is to appeal to the properties of a unique, necessary, and "most real" being. Here I reconstruct the proof in its historical context, focusing on the role played by the theory of modality both in motivating the argument (in the pre-critical period) and, ultimately, in undoing it as a source of knowledge of God's existence (in the critical period). Along the way I examine Kant's version of the now-popular "actualist" thesis that facts about what is possible must be explained by facts about what is actual. I conclude by discussing why the critical Kant claims both that there are rational grounds for accepting the conclusion of his theistic proof, and that such acceptancecan not count as knowledge. This is important, I argue, because the same considerations ultimately motivate his prohibition on knowledge of things-in-themselves generally.

In the first part of the paper I reconstruct Kant's proof of the existence of a 'most real being' while also highlighting the theory of modality that motivates Kant's departure from Leibniz's version of the proof. I go on to argue that it is precisely this departure that makes the being that falls out of the pre-critical proof look more like Spinoza's extended natura naturans than an independent, personal creator-God. In the critical period, Kant seems to think that transcendental idealism allows him to avoid this conclusion, but in the last section of the paper I argue that there is still one important version of the Spinozistic threat that remains. The possibility of things, which can only be regarded as determinations of a single universal possibility, namely of the highest being, proves the existence of the realissimi as a sum total. Kant, Reflexion 6279, from the mid-1780s (18:545) Spinozism is the true conclusion of dogmatic metaphysics. Kant, Reflexion 6050, from the mid-1780s (18:436) 1 Der einzig mögliche Beweisgrund zu einer Demonstration des Daseins Gottes [The Only Possible Basis of a Demonstration of the Existence of God, hereafter 'OPB'] is in the second volume of the Akademie edition. Quotations from Kant's works are translated from Kant 1902-, with the two editions of the Critique of Pure Reason cited by the standard [A/B] pagination, and all other works cited by [volume:page]. I have consulted and sometimes used the translations of OPB by Gordon Treash in Kant 1979, and by David Walford in Kant 1992, as well as Paul Guyer and Allen Wood's translation of the first Critique in Kant 1998.