To this day, philosophers dispute whether Kant was providing a theory of how the mind in fact works or instead a critical theory of how we ought to view knowledge. In either case, Kant’s epistemology and metaphysics are both transcendental. His epistemology is transcendental in that he reasons a priori from what is known to what must be the case in order to account for what is known. And his metaphysics is transcendental in that what ultimately exists exceeds and eludes both our direct knowledge and full understanding, even though we are justified in postulating it according to certain principles of reason.