Kalecki and Keynes share honors for discovering the principle of aggregate demand. But whereas Keynes set out this principle in a static model expressed in Neoclassical language, Kalecki explored it in a disequilibrium dynamic model incorporating Marxian and Classical insights about class conflict and income distribution. Geoffrey Harcourt has characterized Kalecki’s writings as ‘the most profound of the twentieth century’ (Harcourt, 1987). Nonetheless, Kalecki has exerted less influence than Keynes, even among heterodox economists.1