Milton’s Satan is charismatic, but Milton consistently shows his cause to be unjust. Illustration by Edward Sorel

Sometime in 1638, John Milton visited Galileo Galilei in Florence. The great astronomer was old and blind and under house arrest, confined by order of the Inquisition, which had forced him to recant his belief that the earth revolves around the sun, as formulated in his “Dialogue Concerning the Two Chief World Systems.” Milton was thirty years old—his own blindness, his own arrest, and his own cosmological epic, “Paradise Lost,” all lay before him. But the encounter left a deep imprint on him. It crept into “Paradise Lost,” where Satan’s shield looks like the moon seen through Galileo’s telescope, and in Milton’s great defense of free speech, “Areopagitica,” Milton recalls his visit to Galileo and warns that England will buckle under inquisitorial forces if it bows to censorship, “an undeserved thraldom upon learning.”

Beyond the sheer pleasure of picturing the encounter—it’s like those comic-book specials in which Superman meets Batman—there’s something strange about imagining these two figures inhabiting the same age. Though Milton was the much younger man, in some ways his world system seems curiously older than the astronomer’s empirical universe. Milton depicted the earth hanging fixed from a golden chain, and when he contemplated the heavens he saw God enthroned and angels warring. The sense of the new and the old colliding forms part of Milton’s complex aura. The best-known portrait of his mature years makes Milton look like the dyspeptic brother of the man on the Quaker Oats box, but he is far more our contemporary than Shakespeare, who died when Milton was seven. Nobody would ever wonder whether Milton was really the author of his own work. Though “Paradise Lost” is a dilation on a moment in Genesis, it contains passages so personal that you cannot read far without knowing that the author was a blind man fallen on “evil days.” Even in his political prose, Milton will pause to tell us that he is really not all that short, despite what his enemies say. Though he coined the name “Pandemonium”—“all the demons”—for the palace that Satan and his fallen crew build in Hell, he also coined the word “self-esteem,” as contemporary a concept as there is and one that governed much of Milton’s life.

This year is the four-hundredth anniversary of Milton’s birth, and there are a host of Milton books to mark the occasion: the Modern Library has brought out “The Complete Poetry and Essential Prose,” edited by William Kerrigan, John Rumrich, and Stephen M. Fallon, and not long ago Oxford University Press published an edition of “Paradise Lost” introduced by Philip Pullman, whose young-adult trilogy “His Dark Materials” draws its title and much of its mythic energy from “Paradise Lost.” (Titles involving sight and blindness often come from Milton: “Look Homeward, Angel,” “Eyeless in Gaza,” “Darkness at Noon,” “Darkness Visible.”) There is a new edition of “Paradise Lost” edited by the scholar Barbara Lewalski, whose monumental biography of the poet came out a few years ago, and Oxford is launching an eleven-volume series of all Milton’s works, edited by Thomas Corns and Gordon Campbell. Corns and Campbell are also jointly publishing a biography of Milton in time for the birthday, later this year, and Corns is editing “The Milton Encyclopedia,” for Yale University Press. A new critical study by the Princeton scholar Nigel Smith bears the provocative title “Is Milton Better Than Shakespeare?,” and there has been a recent spate of books with titles like “Why Milton Matters” and “Milton in Popular Culture,” pointing out Milton’s influence on everyone from Malcolm X, who read “Paradise Lost” in prison and identified with Satan, to Helen Keller, who created the John Milton Society for the Blind. “Milton in Popular Culture” reminds the reader that in the movie “Animal House,” Donald Sutherland’s Professor Jennings gives a lecture on “Paradise Lost,” taking a bite of an apple as he suggests that the Devil has more fun, before confessing to his unresponsive students that even “Mrs. Milton found Milton boring,” and so does he.

That judgment, alas, still clings to Milton. Never mind that there were actually three Mrs. Miltons, and that Milton, who defended divorce and even polygamy, was a sensuous Puritan, exquisitely attuned to the “amorous delay” of life in Eden: Adam and Eve have sex in the garden before they eat the apple. Never mind that Milton participated in an earthshattering revolution in which he defended the killing of a king; that he was a radical poet who, though he had imaginative power to burn, put aside his art for a decade of political activism. Never mind that he survived imprisonment, the threat of execution and assassination, the plague and the Great Fire of London, and, blind and disillusioned, dictated the greatest long poem in the English language.

John Milton was born on December 9, 1608, in London. His father was a scrivener, a job that went beyond the drawing up of legal documents and included moneylending, which he apparently did with such success that his son did not actually have to work for a living. As a boy, Milton was so studious that, he later recalled, from his twelfth birthday on “scarcely ever did I leave my studies for my bed before the hour of midnight”—thus laying the foundation for vast erudition and eventual blindness. Alongside the usual Latin and Greek, Milton received instruction in French, Italian, and Hebrew, and perhaps even Aramaic and Syriac. His father, who was a gifted musician known for his psalm arrangements, also made sure that his son had a thorough musical education.

When Milton was sixteen, he started at Christ’s College, Cambridge, where he excelled at composing Latin verse and earned the nickname the Lady of Christ’s, because of his delicate looks and chastity—though he also later boasted that as a young man he was seldom without a sword and could beat many stronger men at fencing. After seven years at Cambridge, Milton retreated to his father’s house in the countryside for five more years of isolated, self-directed study. By the end of this time, he had produced a handful of lasting poems, including the great elegy “Lycidas,” occasioned by the drowning death of a college friend.

“Lycidas,” like much of Milton’s longer poetry, takes a nugget of actual narrative—the friend’s shipwreck—and blows it up to allegorical proportions with elaborate allusions, classical forms, a concern for immortality both poetic and spiritual, and even a digressive attack on greedy bishops. But if the allusions escape contemporary readers, and we’re never quite sure why his friend Edward is called Lycidas, there is a deep music that sweeps over the reader like the drowning sea at the heart of the poem: “Look homeward angel now, and melt with ruth. / And, O ye dolphins, waft the hapless youth.” In the end, the poem manages to enact the stages of mourning for a body lost at sea, and to achieve a resolution of psalmlike authority and Christian consolation, fused with unexpected emotional immediacy: