" In 315 CE, for example, the Synod of Neocaesarea (now Niksar, Turkey) banned men from marrying the wife of a dead brother—no levirate marriage. A decade later, in 325, the Council of Nicaea prohibited men from marrying the sister of a dead wife—no sororate marriage—and from marrying Jews, pagans, and heretics. "

― Joseph Henrich , The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous