This 1974 collection of six essays in economic theory represents a major contribution to the field. The first contains the formulation of the Ricardian system, whilst the next two contain, respectively, the author's synthetic treatment of the complex problems of fluctuations and economic growth, and his well-known theorem that in the long run the rate of profit and income distribution are independent of the propensities to save of the working class. The essays that follow provide the missing links: a coherent picture of the macroeconomic theories that have originated in Cambridge and a discussion of their deep foundations in classical economic analysis. Finally, the author evaluates some economic controversies and draws his conclusions on the basic forces determining rate of profit in the process of economic growth. Although the arguments are highly theoretical, they require no knowledge of mathematics beyond elementary calculus and algebra.