The ontological and analytical status of Marxian social theory has been a matter of fierce controversy since Marx’s death, both within and without Marxist circles. A particular source of contention has been over whether Marxism should be construed as an objective science of the capitalist mode of production or as an ethico-philosophical critique of bourgeois society. This is paralleled by the dispute over whether Marxism ought to be considered a humanism or a structuralism. This article addresses both sides of this (...) debate. The argument is that, rather than Marx’s own social thought being split into incompatible poles, giving rise to ‘two Marxisms’, it forms a coherent unity. Marx’s social theory is neither humanist philosophy, nor structural science, but is in fact realist science, which synthesizes these apparent antinomies, and thereby transcends both. (shrink)