There has been a great deal of discussion of social division and polarisation in recent times, but those terms are inadequate. What besets the United States is much worse. Both the right and the left are increasingly defined by a form of Manichaeism, in which the forces of light are taken to be in a death struggle with the forces of darkness. We are in a Manichaean moment.

Manichaeism was a religion founded in the third century by the prophet Mani, born in what is now Iraq. Seeking to synthesise all existing religions and offering its own elaborations, Manichaeism claimed that the principles of Good and Evil are in constant battle.