Farzad Mahhotian (New York University) - Kant’s rejection of chemistry as a science in his first Critique is well known, as is the fact that he softens that position somewhat in the important 2nd edition of that work. Kant’s work on chemistry late in his life is less familiar, and less definitive. Troubled by a number of unresolved problems including those of substance vs substances (the 2nd Analogy of Experience) and the limits of mechanism (the Metaphysical Foundations of Natural Science), and stimulated by developments in chemistry and physics, Kant outlined a “Transition” project in the 1790s, preserved as part of his Opus Postumum (OP). In an attempt to account for chemical properties and reactions, Kant makes bold claims in OP, including an explicit suspension of the first Critique’s key distinction between regulative and constitutive uses of reason. This suspension occurs in the case of aether, the all-pervasive, pluripotent medium of heat and electricity, and significantly, the medium in which matter moves. Whereas the first Critique had, via transcendental deduction, established space as the a priori “form of outer perception,” the OP’s transcendental deduction explicitly hypostasized space as aether, establishing it as the very ground for the possibility of experience. Suspending the constitutive/regulative distinction impacts Kant’s 2nd antinomy (the “Transcendental Atomistic”) by shifting its focus from apparently mereological issues to ones that lie at the core of his concern with chemistry, namely: questions of elemental identity, integrity and interaction. In the context of the lively debate about what exactly Kant was trying to do in OP, an examination of Ernst Cassirer’s philosophy of science presents fruitful lines of inquiry. Whereas the regulative function of reason loses ground in OP’s hypostasization of space, Cassirer’s reinterpretation of the a priori as purely regulative is central to his philosophy of the growth of knowledge. For Cassirer, the a priori is not prior to experience, they are regulative “logical invariants“ that are “contained as a necessary premise in every valid judgment concerning facts.” Placing ‘regulative’ before ‘invariants’ is meant to indicate that these are 1) not to be understood as axioms that have or will appear at any given point in the history of a science, 2) necessarily plural. So, when Cassirer, following Kant, indicates that chemical elements are regulative ideas, not objects, he means that the concept of chemical element is functional and relational. For Cassirer, chemistry is properly scientific when our understanding of any given element is expressed mathematically as a network of relations expressing connections among empirical observations of chemical elements. Cassirer’s regulative idea of a chemical element implicates the whole network of relations represented by the periodic table—with the proviso that the table as we have it is not the final, or best, or only way of understanding chemical elements. Cassirer’s view of chemistry, as a science whose growth is guided by a relational idea of element, is consistent with recent approaches to mathematical chemistry which have shown that a plurality of periodic relations—and thus periodic tables—can be generated by selectively and systematically analyzing relations among various sets of chemical properties.
