Karl Marx

Marx began as a student of Hegel and ended as Hegel's inversion. Where Hegel saw history as the unfolding of Spirit, Marx saw it as the unfolding of material conditions — chiefly, who owns the means of production. Ideas, religion, culture, philosophy: these are superstructure, built on top of an economic base. To understand a society, follow the money — or more precisely, follow the labor.

His critique of capitalism is the most influential in the modern world. Workers, under capitalism, are alienated from what they make, from the act of making, from each other, and from their own human nature. Capital accumulates not by genius but by extracting surplus value from labor. The system contains its own contradictions and, Marx predicted, would eventually be overthrown.

Twentieth-century history happened, in large part, in the shadow of his prediction. Whatever one makes of his political legacy, he is — alongside Hegel and Nietzsche — one of the three indispensable hinges between classical and modern thought.