This books offers a reconstruction of Marx's critique of capitalism through the lens of contemporary realist political theory. Reading Marx through a realist lens enables us to make sense of the connections between (1) Marx's positive concept of freedom, rooted in a theory of human development, (2) his understanding of alienation as diagnosing capitalist unfreedom, and (3) his conception of democracy and socialism, respectively, as cures for this unfreedom. The chapters that follow discuss and respond to some of Marx's most insightful critics such as Max Weber and Friedrich Hayek. This approach clarifies Marx's ideas for a new generation of political thinkers, as well as explaining the challenge they post to contemporary debates about freedom, democracy, and the future economic institution, and demonstrates that these ideas remain both defensible and compelling.