Robert Paul Wolff explains the development of the classical theory of value from Adam Smith to Karl Marx in a form readily accessible to readers unfamiliar with anything more than high school algebra, while at the same time offering to the specialist a fundamental criticism of Marxian political economy and an original and controversial interpretation of Capital. He clarifies recent mathematical reinterpretations of classical political economy, so that philosophers, political scientists, psychologists, and sociologists interested in Marx's theories can understand the modern rehabilitation of his political economy. Originally published in 1985.