2 of 2 Added quote in case the link goes dead

Émile Durkheim.

The sacred–profane dichotomy is an idea posited by French sociologist Émile Durkheim, who considered it to be the central characteristic of religion: "religion is a unified system of beliefs and practices relative to sacred things, that is to say, things set apart and forbidden."

From: Sacred–profane dichotomy on Wikipedia; the quote from Durkheim 1915, p. 47