Immanuel Kant in his "Critique of Pure Reason" (1787 edition) drew a parallel between the "Copernican revolution" and the epistemology of his new transcendental philosophy. Kant's comparison is made in the Preface to the second edition of the "Critique of Pure Reason" (published in 1787; a heavy revision of the first edition of 1781). Kant argues that, just as Copernicus moved from the supposition of heavenly bodies revolving around a stationary spectator to a moving spectator, so metaphysics, "proceeding precisely on the lines of Copernicus' primary hypothesis", should move from assuming that "knowledge must conform to objects" to the supposition that "objects must conform to our ["a priori"] knowledge".