One notorious apikoros named Hiwa al-Balkhi, writing in ninth-century Persia, offered two hundred awkward questions to the faithful. He drew upon himself the usual thunderous curses—’may his name be forgotten, may his bones be worn...

Antisemitism is unique among religious hatreds. It is a racist conspiracy theory fashioned for the needs of messianic and brutal rulers, as dictators from the Tsars to the Islamists via the Nazis have shown. Many...