One fine late 18th-century morning, an affluent collector named Thomas Butts came to call on his friend William Blake and found the poet and his wife sitting stark naked in the summer house of their modest lodgings in Lambeth. The happy couple, “freed from those troublesome disguises which have prevailed since the Fall,” as his early biographer Alexander Gilchrist put it, were reciting Milton’s “Paradise Lost,” with William taking the part of Adam and his wife Catherine the role of Eve. Butts was embarrassed, but Blake called out, “Come in! It’s only Adam and Eve, you know!” If you or I did this, Gilchrist remarks, “it would be time for our friends to call in a doctor,” but in Blake’s case, he writes, a recitation of Milton in the nude served to demonstrate the “full simplicity and naïveté” of the poet’s character. And yet, Blake was neither simple nor naïve. For him, the everyday world was only the thinnest band of a vast spectrum which extended from the smallest grain of sand to all eternity. To become Adam in the Garden — or, for that matter, Moses or Socrates — he needed only to open wide the eyes of his imagination.

William Blake was born in London on November 28, 1757 — exactly 250 years ago today. During his lifetime, he was regarded by many as quite mad; Wordsworth, for instance, thought his “Songs of Innocence and Experience” “the production of insane genius.” To Wordsworth’s credit, he went on to say that Blake’s insanity “interests me more than the sanity of Lord Byron and Walter Scott,” but even this was an unusual opinion. For almost a century after his death, many of his greatest poems remained unpublished and unread while his strange and magnificent paintings and engravings lay hidden in the collections of a few discerning admirers. It took the pioneering efforts of William Butler Yeats and, later, the painstaking scholarly work of Geoffrey Keynes in the 1920s, to bring Blake’s astonishing genius before the world. Today, of course, he is regarded, with justice, as one of the greatest of English artists and poets. And yet, perhaps the most impressive aspect of Blake’s greatness is that, for all his newfound respectability, he still seems as crazy as ever.

Of course, only “thin partitions” separate the madman from the visionary, the crackpot from the prophet. To plunge into one of Blake’s longer poems, such as “America,” and read, “The shadowy daughter of Urthona stood before red Orc, / When fourteen suns had faintly journey’d o’er his dark abode,” is to enter a wild realm of lurid fantasy, which seems to stand as a shadowy alternative to our familiar universe. Who is “Urthona?” And who or what is “Orc?” In her excellent edition of “The Complete Poems” (Penguin, 1,071 pages, $20), the poet Alicia Ostriker glosses the first as “earth-owner” and the second as deriving from the Latin “orcus” or “hell.” Other bizarre names, from Golgonooza (London but also Golgotha) to Enitharmon (a muse as well as “a selfish sky-goddess,” among other things), seem crazier still. And yet, not only are these names always rooted in some elemental sense of the earth, they also serve as highly compressed codes for that mixture of the mythical and the actual which Blake witnessed wherever he turned his eye. For him, the five senses were the gateways to paradise; to trust them was to come close to that “marriage of heaven and hell” to which all his visionary labors were directed and where, somehow, that famous “Tyger Tyger burning bright” might lie down at last with the lamb.

Blake was not a mere fantasist, however, but a visionary who looked hard at the world. As a child, he got spanked for claiming to have seen the prophet Ezekiel “under a tree in the fields.” But he also saw “a little Clod of Clay/ Trodden with the cattles feet” and heard

How the Chimney-sweepers cry
Every blackening Church appals,
And the hapless Soldiers sigh
Runs in blood down Palace walls.

His long, prophetic poems, from “The Book of Los” to the supremely weird “Vala, or the Four Zoas,” present an imaginary, flame-shadowed domain of symbol, and yet each drew its lifeblood from the hard-bitten London streets. Blake did see another world, but it was hidden under the grimy tatters of this one. King George III, whom he detested, and George Washington, whom he admired, were no more real than the vanished patriarchs of biblical times. (“I am Ezekiel!” he would boast in ecstatic moments.) The chimney sweep, the soldier, the “youthful harlot,” were unbearably real to him, and they, too, cast mythic shadows as momentous as any king’s. In one of his greatest poems, “Auguries of Innocence,” discovered decades after his death, he wrote

To see a World in a Grain of Sand
And a Heaven in a Wild Flower
Hold Infinity in the palm of your hand
And Eternity in an hour.

The 18th-century convention of capitalizing nouns takes on new weight in these lines. Blake isn’t merely naming objects here; he is seizing their essences. To behold the greatest in the smallest meant not merely to see beyond the flitting instant, but to witness that instant in all the majesty with which Eternity enrobed it. When he lay on his deathbed, on August 12, 1827, he said that he “was going to that country he had all his life wished to see.” Perhaps the approach of death had made him uncharacteristically diffident. After all, he’d known that country from childhood. He’d witnessed its far-off wonders every day beneath the shabby flagstones of the London streets.

eormsby@nysun.com