Incongruent Counterparts and the Nature of Space

Abstract

In 1768 Kant argued that the fact that there are such objects as left and right hands, which he calls incongruent counterparts, proves the existence of absolute space. In his essay of that year, Concerning the Ultimate Foundation for the Differentiation of Regions in Space, he explicitly breaks with the Leibnizian views he held for the preceding 20 years. The essay is interesting, however, not only because it represents a change in Kant’s thought on space. For one thing, Regions in Space appears just two years before Kant’s Inaugural Dissertation, which contains the first version of the Critical distinction between the sensibility and the understanding, and the analysis of space as a merely subjective form of sensibility. For another, Kant uses incongruent counterparts in three of his Critical writings, including the Dissertation, to support aspects of this Critical theory, conclusions quite different from that of Regions in Space. It is my view that the different uses Kant makes of incongruent counterparts are related, and that the phenomenon provided Kant a basis for rethinking not only the theory of space, but the Leibnizian theory of sensibility as well.