Hans Morgenthau’s revolutionary theory on IR is considered the foundation of IR theory academic discipline as we know it, although that doesn’t neglect the contributions of some of his predecessors who also had successful attempts. Morgenthau’s Politics Among Nations has taken the study of IR as a phenomenon of the world to be an independent branch of social science. He refers to Professor Grayson Krik’s comment that the study of IR has been dominated by either historians or lawyers or dreamers of building a peaceful system (such as Kant), rather than scholars who are concerned about the forces leading world politics. He also did not neglect the connection of knowledge to action and that the purpose is maintaining peace, and in doing so he suggests the study of peace not through ideal thoughts about establishing a federation but rather maintaining peace through two devices: regulating the social forces of the struggle for power, which is balance of power, and normative limitations represented in international law and world public opinion.