When it was published earlier this year, an emigre journalist’s attempt to look at the collapse of Irish Catholicism with fresh eyes was acclaimed by critics inside as well as outside the Church

I remember where I was when I understood, finally, why Ireland’s Catholic Church collapsed. It was a grey January day in 2019 and I had slipped into St Monica’s church on Dublin’s northside.

Mass had just ended – with more brass memorial plaques on the pews than people sitting in them – and I headed into the low-ceilinged sacristy. I hadn’t been here since serving Mass as a child: listening closely for the moment to ring the consecration bells; begging the thurible charcoal to burn. I sought out the dim room beside the sacristy where I would change into my cassock and surplice. There are no altar servers now in St Monica’s and the old changing room is a cluttered storage space. In a corner I caught sight of a block of Oasis, those green blocks of sponge-like foam used to arrange flowers. Soaked with water, the block is heavy and firm. As an altar boy, though, I loved to break off a dry corner, rub it between my fingers and watch it turn to dust.

This, I realised, is what had happened to Irish Catholicism.