Kant turns from an early representational view of cognition to a later anti-representational, epistemic constructivist view, often simply referred to as the Copernican revolution or the Copernican turn. Kant’s Copernican turn belongs to the modern, non-standard interest in epistemic constructivism. At least since Parmenides the standard approach to cognition requires knowledge of the real, reality or the world. In modern philosophy this approach is countered by the emergence of epistemic constructivism as a non-standard solution for the cognitive problem in Francis Bacon, Hobbes, Vico, and others, and independently in Kant. This paper briefly describes consequences of Kant’s Copernican turn concerning at least five themes: (i) cognition, (ii) German idealism, (iii) the subject, (iv) the historical character of knowledge and (v) the success or failure of the philosophical tradition.