This book demonstrates the continuing relevance of Marx's critique of the capitalist system, in which value is simply equated with market price. It includes chapters specifically on the environment and financialisation, and presents Marx's qualitative theory of value and the associated concept of fetishism in a clear and comprehensive manner. Section I demonstrates how fetishism developed in Marx's writing from a journalistic metaphor to an analytical device central to his critique. In Section II, commodity fetishism is distinguished from other forms: of money, capital and interest-bearing capital. There follows an analysis of Marx's complex attempt to distinguish his argument from that of Ricardo, and Samuel Bailey. The section ends with a discussion of the ontological status of value: as a social rather than a natural phenomenon. Section III considers the merits of understanding value by analogy with language, and critically assesses the merits of structural Marxism. Section IV challenges Marx's emphasis solely on production, and considers also exchange and consumption as social relations. Section V critically assesses recent Marx-inspired literature relating to the two key crises of our time, finance and the environment, and identifies strong similarities between the key analytical questions that have been debated in each case.