Throughout this century there has been, and continues to be, a long standing debate about whether the rate of profit falls as technical change accelerates. All the major figures in economics have faced these questions. Its origins can be found in Adam Smith through to Ricardo and Marx, thereafter through all major Marxian thinkers, up to the present. The author's contribution is to provide students with an encyclopedic summary of the debates over time, to clarify complexities and divergent tendencies in the debates. He examines divergent wings of the Marxist debate, other writings on holistic, Cartesian debates from philosophers, sociologists, historians and others, including orthodox economists.