Karl Marx was not only born a Jew; he came froma rabbinical family. His father Heschel Marx accepted Christianity in 1816 in order to practice law in Prussian territory. Like many converts, Marx found it necessary all his life to justify the mass conversion of his family by attacks against his blood brothers. Anti-Semitic expressions of his are to be found mainly in the present essay, in his Class Struggles in France, In the Eighteenth Brumaire of Louis Bonaparte, and in his Letters to Engels, censored by Bebel and Bernstein. Some of the editors of his writings attempted to modify the vindictiveness of Marx’s aggression. Others, like Mehring, even intensified them.