Karl Marx was communism’s most zealous intellectual advocate. His comprehensive writings on the subject laid the foundation for later political leaders, notably V. I. Lenin and Mao Tse-tung, toimpose communism on more than twenty countries.
Marx was born in Trier, Prussia (now Germany), in 1818. He studied philosophy at universities in Bonn and Berlin, earning his doctorate in Jena at the ageof twenty-three. His early radicalism, first as a member of the Young Hegelians, then as editor of a newspaper suppressed for its derisive social and political content, preempted any career aspirationsin academia and forced him to flee to Paris in 1843. It was then that Marx cemented his lifelong friendship with Friedrich Engels. In 1849 Marx moved to London, where he continued to study and write,drawing heavily on works by David Ricardo and Adam Smith. Marx died in London in 1883 in somewhat impoverished surroundings. Most of his adult life, he relied on Engels for financial support.

Atthe request of the Communist League, Marx and Engels coauthored their most famous work, “The Communist Manifesto,” published in 1848. A call to arms for the proletariat—“Workers of the world,unite!”—the manifesto set down the principles on which communism was to evolve. Marx held that history was a series of class struggles between owners of capital (capitalists) and workers (the proletariat). Aswealth became more concentrated in the hands of a few capitalists, he thought, the ranks of an increasingly dissatisfied proletariat would swell, leading to bloody revolution and eventually a classlesssociety.

It has become fashionable to think that Karl Marx was not mainly an economist but instead integrated various disciplines—economics, sociology, political science, history, and so on—into hisphilosophy. But Mark Blaug, a noted historian of economic thought, points out that Marx wrote “no more than a dozen pages on the concept of social class, the theory of the state, and the…