INTERNAL REALISM AND TRANSCENDENTAL IDEALISM: A COMPARISON OF THE PHILOSOPHIES OF PUTNAM AND KANT

Hilary Putnam claims that his "internal realism" is a Kantian philosophy. Gerd Buchdahl agrees, and claims that internal realism should be further extended along Kantian lines. In this dissertation I show that Putnam and Kant are motivated by similar concerns. Both wish to defend our empirical knowledge claims from scepticism. I also show that internal realism and Kant's transcendental idealism are similar in overall structure. Both present transcendental arguments which attempt to show that objectivity must be presupposed if we are to account for the possibility of self-conscious experience. Putnam calls upon a distinction between claims which are "internal to our theories" and those which are "external to our theories." This distinction plays the same role within internal realism that Kant's distinction between the "empirical" and the "transcendental" plays within transcendental idealism. But I argue that in matters of detail these two philosophies are vastly different. Kant uses the a priori conditions of space and time in order to distinguish the empirical level of discourse from the transcendental. Lacking the notion of a priori conditions of human knowledge, Putnam relies upon our empirical theories and descriptions. Moreover, on Putnam's account "empirical objects" are posits or hypothetical entities in the instrumentalist sense. Putnam effectively denies the existence of these objects. Kant achieves objectivity by adopting a transcendental form of "subjectivism" according to which objects in space and time are produced out of our non-empirical perceptions or "intuitions." In light of these differences I argue against Buchdahl's claim that transcendental idealism is an "anticipation" of internal realism. I also suggest that neither internal realism nor transcendental idealism achieve objectivity in a viable and acceptable fashion.