"Look at those big, isolated clumps of buildings rising up above the slates, like brick islands in a lead-coloured sea." "The board-schools?" says Watson, ever the reliable straight man. "Lighthouses, my boy!" says Sherlock. "Beacons of the future! Capsules with hundreds of bright little seeds in each, out of which will spring the wiser, better England of the future!"
Now, how did we exchange that perception for the present popular cynicism about teachers? Britain used to put them on a pedestal along with doctors and vicars. They might be lampooned, but the very lampoons drew their power from the sense of honourable calling: of a status derived from something greater than wealth or smartness. Nobody forgot a good teacher, or forgave a corrupt one.
The decline in public respect probably has some origin in the profound resentment of literary public schoolboys. Shaw coined "He who cannot, teaches" and said school was more cruel than a prison, "because in a prison you are not forced to read books written by the warders and the governor". Aldous Huxley had a character observe that schoolteaching is "the last resort of feeble minds with classical educations"; the departing Paul Pennyfeather in Evelyn Waugh's Decline and Fall is advised by the porter that schoolmastering is "what most of the young gentlemen does, sir, that gets sent down for indecent behaviour". Robert Morley thundered, "Show me the man who enjoyed his schooldays and I will show you a bully and a bore."
It became modish to denigrate school, and by the time the grammar-school generation of writers came along - often to admit that they were made by inspiring teachers - other conditions were in place. We are all adolescents now; and baiting teachers is the standard safe adolescent rebellion. It is boringly predictable for achievers to claim they learnt nothing at school. Occasionally someone will pay tribute to an individual, but to insist that you "just mucked about" is a good way of taking credit for your own success; never mind that without teachers you could not read, count, or find France on the map.
Successive governments in the Sixties and Seventies ignored the plentiful evidence of real failure in some schools, presented year after year by HM Inspectors. When in the Eighties it was abruptly decided that education was a vote-winner, a succession of careerist education ministers brought in compulsory change at bewildering speed, declining to target real failure but instead throwing hundreds of perfectly good schools into anxious uproar with their scattergun directives. Teachers who protested were easily lampooned - by everyone from Prime Ministers down - as surly dinosaurs. The habit of insulting teachers, once confined mainly to disaffected intelligentsia and the Beano, was made mainstream by government. Even in John Major's early, moderate days as PM a speechwriter fed him the conference line "The trendy teachers have had their say - and had their day!" It meant nothing; but it got a roar.
Other factors, of course, helped. The NUT strikers who sent children home in the 1980s, and regularly behaved like intransigent baboons at their own conference, fed the culture of contempt. A new generation of parents appeared, with messy lives, to dump emotionally damaged children into the system and take no further interest beyond threatening the head. The depressing thing is that thumping the head, or screaming at the classroom teacher, was made acceptable partly by all the other insults, all the way from GBS to John Major. Call it the trickle-down effect. It will take more than a few superteacher posts to reverse it.
Libby Purves is the author of `More Lives Than One' (Sceptre, pounds 16.99)