Across the street from my office is Torrington Square, where a stone set in the wall of the terrace marks the house in which the poet Christina Rossetti spent her final decades. Despite being one of the most famous poets of her day, Rossetti was, in her own phrase, ‘tenacious of my obscurity’, pursuing a life of sacrifice, charity and almost obsessional religious devotion. But while she shunned the literary scene, she made herself available to individual callers, who could make an appointment to visit her in Torrington Square.

And so it was that the young Katharine Tynan, over from Ireland in the winter of 1885, called to pay her respects to the great lady. Tynan’s recollections of the meeting, published a couple of decades later, include a striking detail: ‘She told me she never stepped on a scrap of torn paper, but lifted it out of the mud lest perhaps it should have the Holy Name written or printed upon it.’

The way Tynan tells it, there was a scrupulousness in Rossetti’s habits that bordered on eccentricity. And yet Rossetti’s behaviour has an august lineage. Here is Thomas of Celano describing his contemporary St Francis of Assisi: ‘wherever he found any writing, divine or human, whether by the way, in a