Mike Davis, recipient of the MacArthur Fellowship, has written Old Gods, New Enigmas to tackle the remaining interest of Marx's oeuvre. Although everyone agrees that proletarian agency is at the very core of revolutionary doctrine, one searches in vain for any expanded definition, much less canonical treatment. For this reason, Chapter 1 adopts an indirect strategy: a parallel reading of Marx and other socialist thinkers of the classical frame. The goal has been to find accounts of how class capacities and consciousness arose on the principal terrains of social conflict; in the socialized factory and the battles within it for dignity and wages; through sometimes invisible struggles over the labor process; out of the battles of working-class families against landlordism and the high cost of living; from crusades for universal suffrage and against war. Chapter 2, "Marx's Lost Theory," influenced by Erica Benner's work on the politics of nationalism in Marx, argues that Marx's requiem for the failed revolution in France (The Eighteenth Brumaire and Class Struggles in France) stands second only to Capital as an intellectual achievement; moreover, one that is grounded completely in the urgency of revolutionary activism. Chapter 3 focuses on Marx's critic, Kropotkin, who in his scientific persona instigated a great international debate on climate change. Chapter 4, "Who Will Build the Ark?," centers on the debate about the "Anthropocene," a proposed geological epoch, without previous analogue, defined by the biogeochemical impacts of industrial capitalism, was still largely confined to earth science circles.