The materialist conception of history was put forward by Karl Marx and Friedrich Engels and subsequently adopted by their followers and incorporated in the doctrine of Marxism-Leninism. According to "historical materialism," the structure of society and its historical development are determined by "the material conditions of life" or "the mode of production of the material means of existence." These last two phrases are quoted from Marx's preface to his Critique of Political Economy (1859), in which he gave a brief presentation of the view. Marx and Engels had formulated it, however, in their The German Ideology, written in 1845–1846 but not published until 1932. Marx himself gave a brief account in his Poverty of Philosophy (1847) and more concisely perhaps in a letter to Paul Annenkov, written in December 1846, while Marx was working on the Poverty of Philosophy. A vigorous sketch is given in the Communist Manifesto of 1848. Marx's chief...