Kant's Copernican-Newtonian Analogy

There is hardly an analogy in the history of philosophy that has been referred to as often as the one that Kant himself draws in the second preface of the Critique of pure reason between Copernicus' revolution in astronomy and his own revolution in metaphysics; and yet there is to the present day no detailed analysis thereof. The analogy is much more complex than meets the superficial eye: In the first passage (B XVI f.), Kant does not draw a simple comparison to Copernicus' famous heliocentric hypothesis (if he refers to it at all). In the second passage (B XXII, Anm.), Kant connects the reference to Copernicus with a reference to Newton by drawing an extremely rich analogy between the law of gravitation and the moral law of freedom. The revolution in metaphysics is related to the revolution in ethics; that famous analogy of Kant really is a Copernican-Newtonian analogy.