It is only a few decades ago that some of Marx's most important theoretical writings were discovered and published. Marx's Critique of Hegel's Philosophy of Right was published in 1927; the full text of The German Ideology was printed for the first time in 1932; the same year saw also the discovery of the Economic-Philosophical Manuscripts. The draft manuscript of Das Kapital, known as Grundrisse der Kritik der politischen Ökonomie, was printed for the first time as late as 1939.

A considerable gap exists therefore between the interest and discussion evoked by Marx and a real acquaintance with his writings and his theory. Most of the controversies in the Marxist movement raged while the protagonists did not know Marx's own views on the relevant subjects: Plekhanov wrote The Monist View of History without being aware that Marx had covered much of the same ground, though in a different fashion, in The German Ideology; and Lenin wrote his Materialism and Empirio-Criticism without knowing about the existence of the Economic-Philosophical Manuscripts. It sometimes happens that much of what traditionally passes for Marxism is directly contradicted by some of Marx's own writings.

The recent discovery of Marx's earlier writings shifted much of the emphasis in the discussions of Marx's theories. Until this discovery, discussion about Marx was largely limited to a political and ideological debate between various schools of socialists or between Marxists and anti-Marxists.