A seven-book series. Eight movies. A theme park. As the last wave of Harry Potter mania crests — at least until fall when author J.K. Rowling rolls out her Pottermore Web site — we can look back at the most successful publishing adventure since Mao’s “Little Red Book” and wonder:

Would a world without Harry Potter be that much different?

You bet your Quaffles it would. Jim Trelease notes in his “Read-Aloud Handbook” that, along with Oprah Winfrey’s book club, an orphaned boy who found out he was a wizard helped save reading in the 1990s.

Even next to the founder of the OWN Network, Potter Inc. looks profitable, generating nearly $1 billion per film while making Rowling the first author billionaire, a woman who donated $1.6 million to the Labor Party in 2008 and who is richer than the queen of England.

Harry Potter — and piggyback crazes such as Suzanne Collins’ “The Hunger Games” and Stephenie Meyer’s “Twilight” — made novels into blockbuster media events. Without Harry, a generation of new readers would be missing, a suffering book industry would have fizzled out a decade ago, and Hollywood, buoyed by comic-book adaptations chasing the Potter franchise, would be moribund.

But a world without Harry Potter wouldn’t just do less business. Rowling transformed our idea of what stories can do. Harry’s seven adventures are the first 21st-century shared text — a ubiquitous narrative that everyone has read or heard of.

With sales of close to 500 million copies in 67 languages and a CGI-laden celluloid translation that has reached every DVD player on the planet, Harry forged a new, infectious vocabulary among the world’s readers. Dickensian characters from Hermione Granger (no relation) to Severus Snape to the Boy Who Lived to the Dark Lord are recognized by children on six continents.

Universities hold Harry Potter lit-crit classes — and, sometimes, field Quidditch teams. Terms such as “Muggle” and “He Who Must Not Be Named” are now commonplace.

Still, however universal the Hogwarts dialect may be, Rowling’s contribution is greater than wizard jargon.

As novelist Lev Grossman noted in an incisive 2009 Wall Street Journal op-ed titled “Good Books Don’t Have to Be Hard Work,” Harry’s dominance of the bestseller lists — a near-monopoly that forced The New York Times to create a separate children’s tally to “clear some room” — hastened the demise of the literary novel.

These art pieces, heavy on narrator introspection and well-turned phrases but light on drama and character transformation, have been celebrated by the ivory tower and despised by book buyers for three generations. Post-Potter, plot is no longer a crime, and sales do not mean selling out, but successfully engaging readers.

More important than shaking up critical taxonomy, though, is how Rowling reawakened readers’ awareness of what they want in a written story — desires that writers and publishers are now rushing to meet. In a word, that means “meaning.”

Though dismissed by literary critics such as Harold Bloom, A.S. Byatt and William Safire as “a waste of adult time,” Harry Potter has magically restored, revived and renovated allegory.

In 2007, Rowling said the Christian symbols she uses have “always been obvious.” These are what created and still drive Potter-mania. The books sell better than others, not because of the Internet, marketing or movie tie-ins. They dominate bookshelves because they do best what every book is supposed to do: deliver meaning in depth, instructing while delighting, as Christian authors Sir Philip Sidney and C.S. Lewis put it. Without Rowling, we’d be much less delighted.

Poet Ezra Pound once called on writers to “make it new” — to innovate, innovate, innovate.

Lewis expert Andrew Lazo observed that the Inklings, a group of British fantasy writers including Lewis and J.R.R. Tolkien, chose instead to “renovate, renovate, renovate,” restoring narrative to fiction not long after James Joyce threatened to spirit it away.

Rowling has followed the Inklings’ path with an epic mix of schoolboy novel, gothic romance, whodunit and Regency novel of morals and manners. It’s no accident that so many 21st-century bestsellers are serial adventures with paranormal elements featuring sacrificial love and resurrection. It’s the Potter brand and, more important, the mark of an old, broad stream of romantic English literature.

Without Harry Potter, could “Twilight” have put a stunning Bram Stoker spin on the Harlequin romance? Would the dystopian morality play of “The Hunger Games” have proved so popular? Both owe a deep debt to Rowling for the model they employ and for the audience they enjoy.

A world without Harry Potter would be a world of fewer novels with plots. It would be a world of fiction without sales sufficient to merit media attention. It would be a world with more authors who ditch good stories to pursue literary experiments — more Byatts, John Barths and Donald Barthelmes — and fewer readers.

Instead we have a globe filled with children (and many adults) newly engaged not just with an escape from their world, but an exploration of the greater reality beneath its surface.

Rowling has given us an inside bigger than the outside. That’s the magic of reading.

John Granger is the author of “The Deathly Hallows Lectures” and “Unlocking Harry Potter.” He blogs at HogwartsProfessor.com. This column was distributed by The Washington Post, where it first appeared.