The article compares classical and neoclassical monetary theories, discussing their origins and evolution. It explores how neoclassical theory has inverted classical ideas and how this has been confirmed by research in Cambridge. The study also delves into the dichotomy between these theories and discusses the development of monetary theory. It highlights misconceptions in monetarism and the Chicago Paradox. Additionally, it presents a neo-Keynesian alternative to outdated nationalistic monetarism in open economies. The article concludes with insights on the resilience and shortcomings of these theories.