This 1974 collection of six essays in ecomic 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 ecomic growth, and his well-kwn 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 macroecomic theories that have originated in Cambridge and a discussion of their deep foundations in classical ecomic analysis. Finally, the author evaluates some ecomic controversies and draws his conclusions on the basic forces determining rate of profit in the process of ecomic growth. Although the arguments are highly theoretical, they require kwledge of mathematics beyond elementary calculus and algebra.