Decade after decade, teachers try to make new readers love the sort of gritty streetwise writing that will strengthen their grip on the world. And, decade after decade, children's tastes prove the imagination grasps reality in a more mysterious way. In strongly plotted, vividly imagined children's literature, the concept of "escapism" means little.
It is true the Harry Potter craze connects with the bewitching classics of the immediate pre- and postwar years more closely than with the more recent grimmer children's fare. Any Harry fan who needs another fix of comic sorcery should seek out T H White's sparklingly witty, sly Arthurian fantasia from 1938, The Sword in the Stone. Indeed, White's wizard Merlyn has graduated from "a college for Witches and Warlocks under the sea". The fizz and fun of the lessons he gives to his young pupils Kay and Wart mean that the book has dated less than almost any "adult" novel of its year.
Months earlier, JRR Tolkien had published The Hobbit: his Gandalf is the charismatic wizard responsible, then as now, "for so many quiet lads and lasses going off into the Blue for mad adventures". Not long before that, in 1934, PL Travers's Mary Poppins had placed her own benign hex on the sedate Banks household, sliding up the bannisters and serving tea on the ceiling.
Harder to find now is the powerful blend of realism and magic that the former Poet Laureate John Masefield brought to his novels for children, The Midnight Folk and The Box of Delights. At the start of the century, Edith Nesbit had also planted plausible modern children in a colourful terrain of fantasy with Five Children and It and The Phoenix and the Carpet.
The very real Alice Liddell, Lewis Carroll's friend and muse, stands at the source of this rich stream of works that send grubbily authentic kids on fabulous but enriching missions. Look at the Potter plots, and you will also discover archetypal elements common to folk-tales around the globe, as an orphaned or abandoned prince claims his birthright through cunning, craft and ordeal. Such yarns generally end with a crown and a marriage - although we may have to wait until the series' end for that.
Humphrey Carpenter, editor of the Oxford Companion to Children's Literature and himself the inventor of the comic wizard Mr Majeika, likens Rowling's books to "fake antique cars" and finds in them "an ingenious mish-mash of all sort of exciting things" rather than a genuinely new vision.