Environmental degradation, crises in care and the predations of finance capital impose new challenges to human reproduction. It is imperative to understand their roots in capitalism. But how best to do so? This book develops the concept of ‘immanent externalities’ to grasp the non-capitalist life processes produced by – and necessary for – capitalist reproduction. Immanent Externalities thus considers the category of reproduction by means of a philosophical re-reading of the three volumes of Marx’s Capital. In doing so, the book locates capitalism’s fundamental contradiction as that between the reproduction of profit-driven activity and ecologically situated human life, suggesting new orientations for theory and practice today.