The two William Blakes

In 1966, I arrived at college to discover that William Blake had become the patron saint of a revolution. Students in those days confused the poet Blake with certain drawings he had made of leonine prophets and Gods, old men whose beards and hair merged into one luxuriant mane, like the Lord in Blake’s illustrations of the Book of Job, or Job himself, or the titanic Creator measuring out the world with calipers in the frontispiece to Europe. These images, popularized by poster art of the Sixties, hung alongside pyrotechnic pictures of the Beatles and the whiskered Allen Ginsberg and the incomparably hirsute Mr. Natural by R. Crumb. We imagined Blake as a wildman visionary, fashionably shaggy and fashionably mad, one of us, although 150 years dead.

Blake was so beloved and popular that rock stars set his lyrics to music. Professors fought over him. Eighteenth-century experts insisted he was by birth a brother of Cowper and Goldsmith, and...