The Problem of the A Priori in Michael Friedman's Neo-Kantianism

The aim of this article is to lay out the principal aspects of the contemporary philosophical debate about Michael Friedman's conception of the a priori. Friedman has defended the existence of a priori constitutive principles, which make it possible to coordinate the mathematical structure of physical theories with our sensible experience. Although he relies on the Cassierian conception of the a priori to defend a continuity between the mathematical structures of the theories, Friedman, in line with Hans Reichenbach, conceives these constitutive principles as revisable according to changes that occur in physical theories. This conception of constitutive principles has been criticized as too arbitrary in its choice of principles, but also as insufficient and simplistic as a description of the way in which physical theories are applied to experience. Finally, it does not seem possible to reduce Ernst Cassirer's a priori to its regulative role, as Friedman did, since Cassirer also conceived alternative constitutive principles to those of Reichenbach.