of Reflection,” which serves as an Appendix to the Transcendental Analytic in the first Critique—A260-92/B316-49.
16. These ideas are discussed and clarified in Adams 1994, 181-2, 246-7 and Langton 1998, 93-121. Langton in particular attempts to provide a reading of Leibniz's metaphysics—especially its treatment of relations and of space and time—that helps to illuminate Kant's transcendental idealism.
17. Other passages corroborate the impression that this sentence leaves. For instance, in the first passage in the Aesthetic in which Kant claims that transcendental idealism is correct, he writes: “Space represents no property at all of any things in themselves nor any relation of them to each other, i.e., no determination of them that attaches to objects themselves and that remains even if one abstracts from all subjective conditions of intuition” (A26/B42; cf. A39/B56). And in a later passage in the Critique, after describing transcendental idealism, Kant adds (in a section of the text quoted above): “To this idealism is opposed a transcendental realism, which regards time and space as something given in themselves (independent of our sensibility)” (A369; the passage is retained in the second edition).
18. In a recent paper, Jauernig (2008) presents a markedly different interpretation, in part in an attempt to indicate that Kant's criticisms in the Critique are often intended to undermine various Leibnizian positions that Leibniz himself did not embrace. In the course of presenting this interpretive perspective, Jauernig provides a very helpful reading of the so-called Amphiboly, the text in which Kant discusses Leibnizian philosophical views in the most depth.
19. The contention that transcendental idealism and transcendental realism differ in their conceptions of the relation between space and intuition, rather than space and the mind, is significant. For as we have seen, Leibniz does not think that space is real in the sense of being independent of the mind per se; space is a relational order and relations are dependent on “the understanding.” Rather, on Kant's reading, he thinks space is independent of intuition per se.
20. Yet if Leibniz thinks that space is a relational order, that relations are mind-dependent, and that our <space>confused is dependent upon sense perception, is he committed to the idea that space itself is somehow dependent upon sense perception? If so, it is not clear that Kant's characterization of him through the lens of transcendental realism is fair. First, as Kant well knew, Leibniz contends in the New Essays that relations are not merely mind-dependent, but in fact dependent on the understanding, rather than on sense perception. This may suggest that when we consider space through the lens of the understanding—when we focus on our <space>clear & distinct—we find that space is a relational order that depends upon the understanding because it depends upon relations, which in turn are “added” by the understanding to the objects that exist. Perhaps the suggestion here is that relations themselves are not an aspect of our <space>confused but in fact are an aspect of our <space>clear & distinct. One might think our confused representation of space represents space as a kind of independent entity, and not as a relational order, since for Leibniz, the ordinary conception is mistaken in its portrayal of space as a kind of quasi-entity. Of course, space is not actually a quasi-entity, and therefore the correct view of the origin of our representation of space, outlined in Leibniz's last letter to Clarke, should not present space in that fashion. Instead, the correct view of the origin of our representation of space ought to presuppose that space is merely a relational order, and ought to be able to explain that origin while making that presupposition, despite the fact that the representation itself represents space as something other than a relational order. When we focus on our <space>clear & distinct, we find that space is represented as a relational order, and as we have seen, those relations are 