Introduction

Kant published this great work, eleven years in the making, at fifty-seven, and it changed the face of philosophy. He compared his undertaking to the Copernican revolution: where it had been assumed that our knowledge must conform to objects, he proposed that objects must conform to the forms of our knowing. Space and time are the a priori forms of our sensible intuition, and causality and the other categories are the a priori concepts of our understanding; it is they that make experience possible. We can therefore know only 'appearances', things as they appear to us, and not things as they are in themselves. When reason tries to go beyond experience to know the soul, the universe as a whole, and God, it falls into insoluble contradictions and illusions. 'I had to deny knowledge in order to make room for faith.' The work is translated in several volumes.