We do not see light itself, but without it we see nothing at all. People speak of the golden light of Venice, the pale blue of Madrid, or the silver sheen of Cape Cod in September. What they are remembering is atmosphere illumined—the particular range of color in a cityscape or landscape. Light reveals the gift of the world to us and so, from the earliest Greek philosophers through Augustine and Pseudo-Dionysius, light has been associated with the divine. When Suger of St. Denis flooded the choir of his abbey church in 1144 with the light of stained glass, he inaugurated what was then known as opus modernum and only later, at first disparagingly, as Gothic.

Shortly before his death, the English Romantic artist J. M. W. Turner (1775–1851) is reported to have said, “The sun is God.” First exhibited in 1906, his luminous late paintings are recognized today as forerunners of modernism. Their dazzling colors and abstract themes appeal to a sensibility reared on Monet, the postimpressionists, Rothko, Pollock, and de Kooning. But these paintings, for all their mysterious appeal, are in fact unfinished works.

What of the whole artist? The magnificent exhibition “J. M. W. Turner,” now at the Metropolitan Museum of Art through September 21 (after triumphant visits to Dallas and Washington, D.C.), offers him to us in some 150 works—half watercolors, half oils—86 of which are on loan from the Tate Britain. (One misses only his prints.) It is the first retrospective of the artist in America in forty years, and the largest ever here.

Turner was born in London’s Covent Garden, the son of a wigmaker, on whom he depended greatly until the devoted man’s death in 1829. His mother was mentally unstable and died at a young age in an asylum. The son’s bravura talent enabled him to exhibit as early as 1790 at the Royal Academy, where he was made an associate in 1799 and three years later a full academician. Gifted also with an acute business sense, Turner was, for many years, immensely successful. But as his forms became ever more diffuse, the number of his hostile critics multiplied-despite the mighty defense of the most influential of them all, John Ruskin (1819–1900). It did not help that Turner became increasingly eccentric and careless about his personal appearance. (As early as 1813, his rival John Constable [1776–1837] wrote, “He is uncouth but has a wonderful range of mind.”) In late life his reputation declined, and he died in relative obscurity.

The young artist first made his reputation with topographical watercolors based on trips to Wales and Scotland and then with marine subjects such as Fishermen at Sea (1796), his first oil exhibited at the Royal Academy. The aesthetics of the time prized the picturesque and the sublime, as this was defined in Edmund Burke’s A Philosophical Enquiry into the Origin of Our Ideas of the Sublime and the Beautiful (1757). Turner had a natural affinity for landscape that produced the astonishment and terror of which Burke wrote, and he determined to establish that subject on an equal footing with history painting. Claude Lorrain (c. 1600–82) became the classical model for his project. Turner opened his own gallery in London in 1804, and he became famous for finishing canvases on the spot at the Varnishing Days that preceded Royal Academy openings, adding last-minute dramatic details to compete with rivals like Constable.

Snow Storm: Hannibal and His Army Crossing the Alps (1812), shown for the first time in the United States, is the high point of Turner’s early career—and a grand, transitional example of a painting meant, as Burke put it, “to stun the soul.” A high sun barely burns through a tumultuous dark sky in two-thirds of the painting to the right, while a burst of white light to the left reveals the Alps in the distance. Only gradually does the viewer discern the skirmish taking place between the Carthaginians and some local tribesmen, with Hannibal on his elephant barely visible in the low middle horizon. Based on Livy’s account of the crossing in 218 BC, the painting also refers to Napoleon’s march through the Alps to Italy in 1800. Turner thus combines the ancient and the modern, making history itself a source of the sublime. As one critic at the time wrote, “The moral and physical elements are here in powerful unison blended by a most masterly hand, awakening emotions of awe and grandeur.”

Turner’s staunch, lifelong patriotism is evident in loving scenes of the English countryside, as well as sketches of London done on the Thames. It is stronger still in his unfinished painting (1806) of Nelson’s death on his flagship at Trafalgar. Here the stricken hero is cradled as in a Pietà beneath a claustrophobic confusion of billowing sails and rigging in tones of brown and gray, with a bare suggestion of blue sky and the red uniforms of the English sailors pulling the eye toward the central figure. Sixteen years later, King George IV commissioned another version of the battle, a more bombastic work that was the largest of the artist’s career. In contrast to these celebrations of victory, The Field of Waterloo (1818) is a dark and mournful warning of war’s costs, worthy of comparison with Goya’s darkest dreams on the subject.

After these grand pictures, it is curatorial genius on the part of Gary Tinterow and Kathryn Calley Galitz to have installed a gallery (one of three in all) devoted to watercolors, a medium Turner transformed from the province of amateurs to a major art form. (Some nine hundred were subsequently published as engravings.) Their airy assurance and virtuosity prepare the viewer for the bright and happy views of Venice that follow (from the Met’s collection and the National Gallery in Washington), as well as for the mysterious thrill of Staffa, Fingal’s Cave (1832), a scene of an island off the west coast of Scotland that was the first of Turner’s paintings to come to the United States (only the New York show has included it). From this period there is also Ulysses Deriding Polyphemus—Homer’s Odyssey (1829), an original and radiant treatment of the classical theme. It is a narrative meditation on the power of light that the artist painted after a trip to Italy. John Ruskin considered it “the central picture in [his] career.”

If the Ulysses is dazzling, The Burning of the House of Lords and Commons, 16th October, 1834 is almost blinding. Indeed, this great picture from the Philadelphia Museum of Art is probably the high point of the exhibition. Turner painted it—along with another version now in the Cleveland Museum of Art—in the year after the event, which he had observed from the banks of the Thames. He probably first recorded the scene in pencil sketches before he produced watercolor renderings in his studio, nine stunning examples of which are in the show. We see the conflagration from the south bank of the river, looking north to the Palace of Westminster, with Westminster Bridge just to the east. As the seat of British government dissolves before us, the northern end of the bridge also seems to be on fire. The wind had actually blown the fire toward Westminster Abbey, but Turner turns it south for dramatic effect. Firelight and moonlight sing sublimely together, and it is hard to remember that the piece is a threnody.

Perhaps, though, you will favor the late work. Increasingly abstract, and generally in smaller format, the themes of these canvases and watercolors are really pretexts for rhapsodies of light and color. An avid student of optics, Turner read Goethe’s Theory of Colors (translated into English in 1840), and in 1843 critically engaged it in a pair of roughly square canvases treating the biblical theme of the Deluge. Another biblical theme in square format is The Angel Standing in the Sun (1846), perhaps prompted by the first volume of Ruskin’s Modern Painters (1843), which described Turner as “the great Angel of the Apocalypse.” There are also glorious watercolors painted in Switzerland between 1842 and 1845. Most dramatic of all is Peace—Burial at Sea (1842), an eloquent nocturnal tribute in oil to the artist’s painter friend, Sir David Wilkie, who died off the coast of Gibraltar the year before.

Turner was apparently a believing Christian, and moral seriousness flows as an undercurrent through his work, from beginning to end. Giving the artist’s moral sense an urgent tension is the paradox that Andrew Wilton has identified as Turner’s basic theme: “the pathetic inadequacy of human beings in an ineffably beautiful and terrible universe.” Before the captivating and often ravishing canvases and watercolors at the Met, the viewer is by turns (and sometimes it seems simultaneously) enthralled and appalled. The Waterloo scene, rivaling Goya in its descriptive beauty, spares us none of war’s horror. The burning Parliament is a gorgeous image of destruction.

If only the marvelously generous Tate could also have lent The Fighting Temeraire, Tugged to Her Last Berth to Be Broken Up (1839), which Turner so cherished that he could never bring himself to sell it. Three years ago, BBC listeners voted it the greatest painting in the world. Turner had seen the heroic vessel of Trafalgar being towed off for dismantling and painted the scene a year later. An undeniable symbol of age and mortality, “my Darling,” as Turner called it, conveys also a transcendent sense of acceptance. Looking at the grand, ivory-lit survivor pulled off by the black tugboat with the setting sun behind it, I’ve more than once thought of the words of the Indian poet Rabindranath Tagore:  

Death is not extinguishing the light   
   but putting out the lamp   
      because the dawn has come.