Peace Studies as a discipline must have a system, as shown by Immanuel Kant and Johan Galtung. As human beings should recognize that nuclear weapons are evil, peace researchers must first try to find the way to eliminate nuclear weapons by appealing to governments, international organizations, NGOs, and all other means. Since the time I visited the United Nations Headquarters in New York in 1982, I have been impressed by the idea that peace, human rights and development are linked to each other. Professor Anatol Rapoport once told me that the word ""trinity"" would best symbolize the linkage between peace, human rights and development. The linkage or ""trinity"" should be understood not ideally, but concretely and systematically. It should also be noted that the principle of peace enshrined in the Constitution of Japan would contribute to systematization of Peace Studies.