Jason Webster asks if the detective is the “priestly” figure of modern literature:
One only needs to look at the names of famous sleuths to see how deeply they draw on the authority of religion. The most obvious example is John Rhode’s forensic scientist Dr Priestley in the 1920s, followed in the 1950s by John Creasey’s Commander George Gideon (think hotel Bibles). Even among contemporary characters, names with religious connotations are common: Adrian Monk and John Luther have both been recent hits on television, while Michael Dibdin’s Aurelio Zen, James Patterson’s Alex Cross and Leslie Charteris’s Simon Templar, alias ‘The Saint’, are hugely popular literary creations.
It isn’t only the names that give the game away. Consider Holmes, the greatest fictional detective of them all. He is (probably) celibate. He acts in the ordinary world, but his natural habitat is a mystical retreat in which he isolates himself for weeks, emerging with insights that can resolve the perplexities of those around him. His London address at 221B Baker Street is a kind of monastery in the heart of the metropolis. ‘For days on end,’ Dr Watson reports, ‘he would lie upon the sofa in the sitting-room, hardly uttering a word or moving a muscle from morning to night.’ Holmes is like a Franciscan, periodically leaving the friary to offer wisdom to the wider community. Or perhaps he is a shaman, locked in his refuge, taking powerful drugs and communing with spirits before returning to ordinary life with mysterious powers and solutions.
(Image of Sherlock Holmes in “The Adventure of the Missing Three-Quarter” via Wikimedia)
The Dish 
