Impressed by the accomplishments of mathematics and physics during the seventeenth and eighteenth centuries, Kant was prompted to ask whether metaphysics might not profit from a consideration of at least the methods adopted by these enquiries. In the preface to the second edition of the Critique of Pure Reason he cites the experiment of Copernicus' in which, by reversing the habitually conceived relation between the earth and the other planets, this scientist was able to render a more exact explanation of (...) their respective activities. On the analogy of such a procedure, Kant asks how it would be in metaphysics if instead of our assuming, as he claims had been done in the past, that all knowledge depends wholly on its abject, we assume the reverse relationship, and investigate the possibility that abjects depend in certain respects upon our knowledge. [...]. (shrink)