Lecture 3/8. Kant's so-called "Copernican" revolution in metaphysics begins with the recognition of the observer's contribution to the observation. Thus, to the extent that Hume's empiricism restricts knowledge to experience, empiricism succeeds only by accepting the a priori grounding of experience itself. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/