A book of comparative ethnography, published in Paris in 1909 by a folklorist who never held a university chair in France. It reads like a filing system because it is one.

I have tried to assemble here all the ceremonial patterns which accompany a passage from one situation to another or from one cosmic or social world to another.

Arnold van Gennep, Les rites de passage, 1909

He had collected ceremonies from everywhere he could reach — births, initiations, weddings, funerals, pregnancy, the reception of a stranger into a village, the crossing of a frontier — and the finding is that they are not different ceremonies. They are one ceremony, performed on different occasions, in three movements.

• separation — you are removed from what you were;
• margin — you are held, and you are neither;
• aggregation — you are returned, as something else.

A funeral and a wedding have the same skeleton. That is the book, and it took a career of index cards to be able to say it in a sentence.

The middle movement had no name before him. He called it the limen: the threshold, the door-sill, the strip of a doorway that is stood on and not occupied.

He assumed nobody stays on the sill. There is no chapter for that.