Leibniz’s views on modality are among the most discussed by his interpreters. Although most of the discussion has focused on Leibniz’s analyses of modality, this essay explores Leibniz’s grounding of modality. Leibniz holds that possibilities and possibilia are grounded in the intellect of God. Although other early moderns agreed that modal truths are in some way dependent on God, there were sharp disagreements surrounding two distinct questions: (1) On what in God do modal truths and modal truth-makers depend? (2) What (...) is the manner(s) of dependence by which modal truths and modal truth-makers depend on God? Very roughly, Leibniz’s own answers are: (1) God’s intellect and (2) a form of ontological dependence. The essay first distinguishes Leibniz’s account from two nearby (and often misunderstood) alternatives found in Descartes and Spinoza. It then examines Leibniz’s theory in detail, showing how, on his account, God’s ideas provide both truth-makers for possibilities and necessities and an ontological foothold for those truth-makers, thereby explaining modal truths. Along the way, it suggests several refinements and possible amendments to Leibniz’s grounding thesis. It then defends Leibniz against a pair of recent objections by Robert Merrihew Adams and Andrew Chignell that invoke the early work of Kant. I conclude that whereas Leibniz’s alternative avoids collapsing into yet another form of Spinozism, the alternatives proposed by Adams, Chignell, and the early Kant do not. (shrink)

Much recent attention has been paid to Kant’s account of the unity of space in the Critique of Pure Reason, not least because of the significant implications of that view for other key critical-period doctrines. But far less attention has been paid to the development of Kant’s account of the unity of space. This paper aims to offer a systematic account of Kant’s pre-critical account of the unity of space. On the view presented herein, Kant’s early account of the unity (...) of space is deeply rooted in his pre-critical cosmological views. In particular, I argue that Kant sees the unity of space as grounded in the cosmological unity of the world of substances, which is itself rooted in the divine conservation of all substances in relations of mutual causal dependence. I contend that the seeds of this view are present in the late 1740s and 1750s, but that this view receives its fullest and most complete expression in the 1770 Inaugural Dissertation. The final section of the paper considers the fate of Kant’s pre-critical account of the unity of space. I contend that the theory is excluded from the Critique of Pure Reason in light of the strict epistemological strictures adopted in that text. But considerable textual evidence shows that Kant continues to aver the theory throughout the 1770s and 1780s in the looser epistemic context of his lectures. I contend, then, that this theory is not abandoned at all. Rather, like Kant’s 1763 proof of the existence of God, it is epistemically demoted: it is Kant’s preferred view, but one that falls short of the demanding epistemic standards of the critical philosophy. (shrink)

The nature of Kant’s criticism of his pre-Critical ‘possibility proof’ for the existence of God, implicit in the account of the Transcendental Ideal in the Critique of Pure Reason, is still under dispute. Two issues are at stake: the error in the proof and diagnosis of the reason for committing it. I offer a new way to connect these issues. In contrast with accounts that locate the motivation for the error in reason’s interest in an unconditioned causal ground of all (...) contingent existence, I argue that it lies in reason’s interest in another kind of unconditioned ground, collective unity. Unlike the conception of the former, that of the latter directly explains the problematic ontological assumption of the possibility proof, the existence of intelligible objects as the ground of possibility. I argue that such Platonic entities are assumed because they are amenable to the kind of unity prescribed by reason. However, since the interest in collective unity has a legitimate regulative use when applied to the systematic unity of nature, the conception of God entailed by the possibility proof is retained as a regulative idea of reason. (shrink)

Andrew Chignell and Omri Boehm have recently argued that Kant’s pre-Critical proof for the existence of God entails a Spinozistic conception of God and hence substance monism. The basis for this reading is the assumption common in the literature that God grounds possibilities by exemplifying them. In this article I take issue with this assumption and argue for an alternative Leibnizian reading, according to which possibilities are grounded in essences united in God’s mind (later also described as Platonic ideas intuited (...) by God). I show that this view about the distinction between God’s cognition of essences as the ground of possibility and the actual world is not only explicitly stated by Kant, but is also consistent with his metaphysical picture of teleology in nature and causality during the pre-Critical period. Finally, I suggest that the distinction between the conceptual order of essences embodied in the idea of God and the order of the objects of experience plays a role in the transition into the Critical system, where it is transformed into the distinction between the intelligible and the sensible worlds. (shrink)

Andrew Chignell recently proposed an original reconstruction of Kant's ‘Only Possible Argument’ for the existence of God. Chignell claims that what motivates the ‘Grounding Premise’ of Kant's proof, ‘real possibility must be grounded in actuality’, is the requirement that the predicates of a really possible thing must be ‘really harmonious’, i.e. compatible in an extra-logical or metaphysical sense. I take issue with Chignell's reconstruction. First, the pre-Critical Kant does not present ‘real harmony’ as a general condition of real possibility. Second, (...) the real harmony requirement is not what motivates the ‘Grounding Premise’ of the proof. Instead, this premise is sufficiently motivated by what Chignell labels the ‘content’ requirement. Finally, Kant's downgrading of the proof in his Critical period is not based on a concern regarding the real harmony of the predicates of God, but on his Critical restrictions on cognition in general and modal cognition in particular. (shrink)

There has been a groundswell of interest in the account of modality that Kant sets forth in his pre-Critical Only Possible Argument. Andrew Chignell's reconstruction of Kant's theistic argument in terms of what he calls has a prima facie advantage in that it appears to be able to block the plurality objection (namely, that even if every modal fact presupposes some ground, this does not entail that all modal facts share the same ground). I argue that it is both textually (...) and philosophically problematic to interpret Kant's argument in terms of real harmony. Then, I set forth an alternative response to the plurality objection which does not require the adoption of the problematic notion of real harmony. Instead, I argue that the objection can be overcome by observing that the argument seeks to ground modal facts as a totality and that, according to Kant, such relations can be accounted for only by their schematization in a single intellect. (shrink)