Friedrich Engels, the other half of the Marx-Engels double act, has a lot to answer for. The German philosopher fell for the crackpot theory, first proposed by a Swiss antiquarian named J J Bachofen, that humans started off in matriarchies when we lived in a state of nature. Only after the men wrested control from the sappy women and started building civilisation did the right and proper state of patriarchy come into being. Engels went to town on the idea in his 1884 book, The Origin of the Family, Private Property and the State, calling progress “the world-historical defeat of the female sex”. Where he went, an army of Marxists and chauvinists followed.