One morning in Rome, more than thirty years ago, I was drinking coffee with an American professor of anthropology. From our pavement café we could look across at the circular bulk of one of the city’s more unusual churches, the Pantheon, originally a temple dedicated to the gods of old.

‘Christian veneration of the saints was surely derived from pagan worship of the gods,’ my companion (an atheist) remarked. ‘How I wish there were some sort of store around here where you could buy saints’ relics.’

‘There is,’ I said (to his amazement). ‘Not far away as it happens. I’ll take you there if you like.’

Within minutes we thus found ourselves in a place called the Vicariate of Rome, one of those stray buildings owned ‘extraterritorially’ by the Vatican. It housed a curious and little known department containing hundreds – nay, thousands – of saintly relics.

My friend’s eyes glinted with excitement. He was rivetted by the way these minuscule objects – many associated with alleged cures, special favours and popular devotions – were indexed, documented and neatly stored in tiny pigeon-holes.

He ordered two ‘first class’ relics (chips from saints’ bones) and three ‘second class’ ones (fragments of their garments) to add to his vast collection of books and miscellaneous items concerned with the world of superstition. ‘Yes, superstition!’ he robustly declared. ‘That’s what it is. But it is the connection