Die deutsche Ideologie
From 1839 to 1841, Bauer was a teacher, mentor and close friend of Karl Marx, but in 1841 they came to a break. Marx, with Friedrich Engels, had formulated a socialist and communistic programme that Bruno Bauer firmly rejected. Marx and Engels in turn expressed their break with Bauer in two books: "The Holy Family" (1845) and "The German Ideology" (1846).