Abstract
This paper traces the development of transcendental philosophy in the 20th century back to the strongly perceived need to preserve an exclusive area of a priori research for philosophy. It will argue that a genuine sort of aprioristic philosophical inquiry does not in fact require the step from descriptive psychology to transcendental phenomenology taken by Husserl and well attested in his works from at least his 1911 essay "Philosophy as Strict Science", nor does it require the "detranscendentalization" of Husserlian phenomenology carried out in the work of Heidegger. On the contrary, as I will show, recent work in philosophy connected to the development of the cognitive sciences suggests how it is possible to obtain significant a priori knowledge, by a sort of "wide reflexive equilibrium", consistently with the empirical impugnability of knowledge required by Quinean empiricism.