"The vulgar economists of capitalism have tried to deny this contradiction of capitalist production ever since it was hinted at by the likes of Sismondi, and logically suggested by the law of value based on labour, first proposed by Adam Smith and David Ricardo. The apologists dropped classical theory and turned to a marginal utility theory of value to replace the dangerous labour theory.  They turned to equilibrium as the main tendency of modern economies and they ignored the effect of time and change.  Only the market and exchange became matters of economic analysis, not the production and exploitation of labour."

Grossman on capitalism's contradictions