the crisis research of medieval intellectual system; The emergence of Descartes' methodology and its impact on Hans. J. Morgenthau's theory of classical realism

René Descartes (1596-1650), the French philosopher of the Age of Enlightenment, is known by many experts as the most important founder of new philosophy. He is the first great philosopher after the Middle Ages who belonged to the school of rationalism and emphasizes that it is not possible to simply understand what human senses perceive. It offers certainty, but it is only on the basis of reason that certain knowledge can be achieved. This research article is an analysis about the place of Descartes' thought in Hans's intellectual system. J. Morgenthau is a prominent theorist of classical realism of the 20th century, whose purpose is to show the direct and indirect effects of Descartes' thought on Morgenthau's methodology in presenting his theory. Morgenth's realism is a kind of attempt to present a scientific model of political developments at the level of human political behavior, in which it is emphasized that in examining foreign policy, political realities should be dealt with in the framework of a rational plan and context. In this article, we try to explore some of these influences.