Figurative Synthesis, Spatial Unity and the Possibility of Perceptual Knowledge

Abstract

This chapter expands on the theme of synthesis and addresses Kant’s argument in that second step about how figurative synthesis (synthesis speciosa) or transcendental or productive imagination accounts for the possibility of perceptual knowledge of spatiotemporal objects. I consider three key points: First, I discuss some systematic issues regarding the precise relation between intellectual and figurative synthesis. I argue that figurative synthesis is in fact intellectual synthesis in the mode of the a priori synthesis of apprehension in empirical intuition, and that therefore figurative synthesis is always a function of the understanding, and hence can never operate independently of it. Figurative synthesis is simply how the understanding operates in the empirical domain, in an actual empirical judgement. This undercuts certain nonconceptualist construals of Kant’s argument, which argue that nonconceptual content is synthesised content by virtue of figurative synthesis, but not synthesised by virtue of intellectual synthesis, since the latter ex hypothesi implies conceptualisation by the understanding. Secondly, I examine in detail how figurative synthesis must be seen as providing the a priori formal ground for the knowledge of concrete spatiotemporal objects, and why synthesis is in one sense also a sufficient condition for the empirical reality of such objects but in another sense not a sufficient condition of their existence. I shall particularly pay attention to the role that synthesis plays in the determination of space, and stress the fact that Kant’s claims regarding the conceptual determination of space does not require, and in fact cannot mean, a collapse between what is receptively given in intuition and the spontaneous act of determining intuitions, nor imply that necessarily, what is receptively given is subject to the categories. My reading allows for a notion of not-yet-determined metaphysical space as irreducibly nonconceptual, in the sense that its unity is sui generis and not reliant on the unity of the understanding that is required for determinate spaces. Thirdly, I address Kant’s claims that the categories, through figurative synthesis, constitute “the original ground of [nature’s] necessary lawfulness” (B165) and that the laws of nature “exist just as little in the appearances, but rather exist only relative to the subject in which the appearances inhere, insofar as it has understanding” (B164). Of particular concern here is the need for the unity of apperception, hence the categories by means of figurative synthesis, as a guarantee and foundation of the a priori knowable uniformity of nature.