Martin Wight has distinguished among three traditions or worldviews of the a) Machiavellian or Hobbesian pessimists for whom power is crucial, b) The Grotian pragmatists or rationalists for whom cooperation matters, and c) The Kantian optimists for whom ideas and legal principles are vital. I have argued that the theoretical debates in international relations can be reduced to these three basic worldviews that have reappeared in the four debates since international relations emerged as a scientific discipline in 1919. My goal is twofold: