In my paper titled "What is Post Keynesian Economics" presented at the 4th International Post Keynesian Workshop at the University of Tennessee, I argued that Keynes's Treatise and the General Theory provided the groundwork for an intellectual revolution in economics. By questioning some basic assumptions and bringing money and financial markets into the determination of real output and employment, Keynes posed a serious challenge to the classical model that is still relevant today. Unfortunately this revolution was aborted an ....