This article proposes an understanding of critical international theory as an historical rather than philosophical mode of knowledge. To excavate this historical mode of theorizing it offers an alternative account of CIT's intellectual sources. While most accounts of critical international theory tend to focus on inheritances from Kant, Marx and Gramsci, or allude in general terms to debts to the Frankfurt School and the Enlightenment, this is not always the case. Robert Cox, for example, has repeatedly professed intellectual debts to (...) realism and historicism. The argument advanced here builds on Cox by situating CIT in a longer intellectual heritage that extends from Renaissance humanism and passes through Absolutist historiography before reaching Enlightenment civil histories, including Vico's history of civil institutions. The critical element in this intellectual heritage was the formation of a secular political historicism critically disposed to metaphysical claims based on moral philosophies. By recovering this neglected inheritance of criticism, we can articulate not only a critical theory to rival problem-solving theories, but propose a conception of theory as a historical mode of knowledge that rivals philosophical modes yet remains critical by questioning prevailing intellectual assumptions in International Relations theory. (shrink)