Copernicus's De revolutionibus orbium coelestium (On the revolutions of the heavenly spheres, 1543) demonstrates that the sun is the center of the solar system and thus destroys the earlier Ptolemais system, which assumed that the heavenly bodies rotated around the earth. The so-called 'Copernican revolution' has therefore come to be seen as the archetypal example of a scientific revolution (or epistemological break), and analogies with it play an important role in attempts to demonstrate or assert the scientific nature of emergent theories.
In the preface to the second edition of his Critique of Pure Reason (1787), Kant explains that he proposes to do for philosophy 'just what Copernicus did in attempting to explain the celestial movements.' Kant's Copernican revolution in metaphysics reverses the traditional theory of cognition by demonstrating that knowledge does not conform to a realm of objects; objects conform, rather, to ways of knowing and it follows that we know them as they appear to us, and not as they exist in themselves.
Freud describes psychoanalysis (1916-1917) as the last of three Copernican revolutions, or of three major blows to the self-love of man. Copernicus demonstrated that the earth was not the center of the universe, and Darwin's theory of evolution dethrones man from his privileged place in creation. Psychoanalysis then delivers the most wounding blow of all, as the discovery of the unconscious reveals that the ego is not master in its own house.