Even in a Church with no deficit of mystery, there is a special place reserved for Carmelite nuns. These followers of the austere mystic, St Teresa of Avila, who live their lives behind a grille in a now-dwindling number of small monasteries dotted around the country, often seem to be an impossible enigma.

To most people, Carmelites are only ever encountered as a group, probably at Mass, glimpsed across a monastery church in their identikit brown habits and swirling creamy white cloaks. Too often they seem like a race apart, a strange race called “nuns”, rather than individual women. To understand Carmelites, we have to understand they are women.

This has never been difficult for me: my father’s only sister entered Carmel the year before I was born, and the summers of my childhood were spent playing on the floor in the parlour before graduating to spend a much-cherished week living inside the enclosure with her, and her sisters, in order to write about their life.