 Unsurprisingly, Kant influenced empirical theory in early 19th-century Germany. (However, it was his transcendental psychology in the Critique of Pure Reason, not his views on empirical psychology, that proved to be most influential.) In particular, his doctrine of space and time as forms of sensibility was given a naturalistic construal in the physiology and psychology of perception. Since for Kant an a priori form of intuition need not be innate, it could unfold in the course of sensory experience. This led J.G. Steinbuch (1811) and C. Th. Tourtual (1827) to investigate empirically how spatial representation arises – specifically, how particular subjects become able to see things as arrayed in space, perceive objects as three-dimensional, and represent spatial structures more generally. Hatfield (1990, Chapter 4) surveys these post-Kantian developments in more detail. 