German Romantic

The wandering exile is a common Romantic figure. But why was it so inspiring to 19th-century German artists? Robert Hughes on how a nation rediscovered itself.

Moonstruck... Caspar David Friedrich's Man and Woman Contemplating the Moon, 1818/1824. Photo: Staatliche Museen zu Berlin

Good stuff, bad weather. "Whenever a storm with thunder and lightning moved over the sea he would hurry out to the top of the cliffs as if he had a pact of friendship with the forces of nature, or even go on into the oakwood where the lightning had split a tall tree from top to bottom, and murmur, 'How great, how mighty, how wonderful!'" Thus a friend remembered the wanderings of Caspar David Friedrich, as a young painter on the island of Rügen in 1802. Man among the unchained elements, drawing a sense of his own mingled littleness and grandeur from their convulsion: it is the archetype of Romantic scenarios, Byron on the ocean, Turner in the Alps, and any number of alert, soulful young German idealists contemplating their travels north to the Baltic or south to the Bay of Naples. Romanticism was the primal urge of high German culture in the early 19th century. Nowhere can the force of this, as reflected in painting, be better appreciated at present than in Dublin, where the National Gallery of Ireland is celebrating its 150th anniversary with a wonderful loan show from the Nationalgalerie in Berlin, A German Dream: Masterpieces of Romanticism .

It sometimes happens that a great cultural movement goes hand in hand with the self-discovery of the country in which it takes place, and so it was with German Romantic painting. The early 19th century in Germany was tough on intellectuals; in the wake of the Napoleonic wars and the Congress of Vienna came a fierce persecution of democratic ideas and those who held them, so that to assert one's "German-ness" as an artist, one's allegiance to folk culture and local history, was in some ways a radical act. If a painter portrayed himself or others in altdeutsch (old-fashioned German) costume, that too was a political statement. Gothic was traditional, Greek was modern. "We are not Greeks any more," wrote Goethe, and the implications of this thought went deep.

You see them, for instance, in the extraordinary landscapes with Gothic churches, attended by devout pilgrimages from the whole region, back-lit in all their staggering complication of tracery, by the architect Karl Friedrich Schinkel (1781-1841). Beyond comparison the greatest neo-classical German architect of the 19th century, Schinkel simply vaporised the boundaries between the classic and Romantic sensibilities; Prussia might think of itself, through his architecture, as a reborn Doric Greece, but his paintings equally celebrate the nationalist continuity of the Gothic past.

You can see Schinkel's paintings as a call to nationalist self-confidence. But there was also an inwardness, whispering and pleading to be let out. So the exemplary Romantic was partly an enraptured patriot and partly an exile within his own culture. This chimed with the preferences of Romantic painting for the wanderer, the solitary figure turning his back on his society to better contemplate the distant moon, the silent bay or the landscapes of a foreign land.

And that was where Caspar David Friedrich came in, quiet, clear and (eventually) dominant. Friedrich was the son of a soapmaker, born in the insignificant provincial seaport of Griefswald in 1774. He died obscure and more than slightly mad in Dresden in 1840.

His modernity isn't due so much to the "look" of his paintings, carefully composed, thinly laid and breathlessly static, as to the ideas behind them. The question they ask is the one asked by his contemporary, the philosopher Friedrich Schlegel: "Can mankind be understood divorced from nature, and is it so very different from other manifestations of nature?"

The answer from Schlegel and Friedrich, as from a congregation of ecologists and earth people since, was no and no again. Friedrich did not believe he, or anyone else, was "outside" of nature, and when he painted images like the Nationalgalerie's Man and Woman Contemplating the Moon , 1818/1824, that was the point he was making. The human pair, in their "Old German" clothes, are scarcely different in tone or modelling from the deep dramas of nature around them, the leaning rocks and the half-uprooted, venerable tree in silhouette. They gaze enraptured at the moon - significantly, when Friedrich was asked what they were doing, he ironically retorted: "These two are plotting some demagogic activities."

If there is one word for the mood of Friedrich's pictures it is "longing": the desire, never satisfied, to escape from the secular conditions of life into union with a distant nature, to be absorbed in it, to become one with the Great Other, whether that other is a mountain crag, an ancient but enduring tree, the calm of a horizontal sea, or the stillness of a cloud.

Sometimes actual symbols of formal religion do appear - a gothic spire, a cross on a mountain pass. But they are not really necessary, since the object of Friedrich's worship is nature rather than its creator. The watchers in his paintings, turning their backs to us, gaze at nature on our behalf; it is a form of vicarious prayer, and that was how Friedrich's rather small audience interpreted it.

Sometimes the painting doesn't even need the watcher. Carl Gustav Carus (1789-1869) went to Naples in the travelling party of Prince Friedrich Augustus of Saxony in 1828, and his reaction to his quarters in the Casino Reale would strike a chord with any later tourist who has ever had unexpectedly good luck with a hotel. Led upstairs by an elderly chamberlain, "I enter, and in front of me lie Vesuvius, the sea, the castle, and the blue distance! I thanked God profusely. Not only had He graciously led me to my destination but He had considered me worthy of such a room!"

The mood is very different from the indignant whining about bedbugs and inedible food of a Smollett on the non-so-grand tour, and in Balcony Room with a View of the Bay of Naples , 1829, Carus painted what may be the first visual prayer of thanks to the Almighty for a concierge's kindness ever done by a gratified tourist - the archetypal blue view past the shutters, a neo-classical Matisse almost, with a guitar propped against the doorframe echoing the slant of a felucca's rigging just beyond it.

German Romanticism did indeed carry a strong religious streak. Some of its exponents saw themselves as spiritual reformers, sent by the zeitgeist to reform a culture muddied, as they thought, by relativism and realism. Like the Pre-Raphaelite Brotherhood in England, they would remind viewers of the lost (but regainable) piety and innocence of an earlier world, that of the New Testament. They called themselves the Nazarenes. The squeaky-clean, idealised form of Christian representation they went in for - only a hair away from pious kitsch, and sometimes not even that, to modern eyes - is summed up in Friedrich Overbeck's Christ in the House of Mary and Martha , 1812-16, a highly coloured but rigidly frozen pastiche of Raphael. A little of the Nazarenes' cloying, self-conscious pietism goes a long way, and their idea of turning themselves into a sort of monastic order of art-priests (who lived in a sort of commune until 1820 in an actual monastery in Rome, that of San Isidro on the Pincio) now seems absurd. Yet you can't doubt the sincerity of their enterprise, or the intensity of their cult of friend ship. In 1811, when Wilhelm and Ridolfo Schadow, the artist sons of the Prussian neo-classical sculptor Johann Gottfried Schadow, caught their first distant glimpse of the Eternal City, they swore an oath that they "would rather stay dead in Rome than return to our home city as unknowns". Four years later, Wilhelm painted one of the classics of German group portraiture: himself and his brother clasping hands in manly resolution, while their friend and mentor, the Danish sculptor Bertel Thorwaldsen, seals the bond with his left hand on Ridolfo's shoulder and a laurel wreath in his right. It's almost an artworld version of David's picture of heroic brotherhood, The Oath of the Horatii . The Schadow boys are clearly bound to win the battle for Noble Art, and they will do it with their pals as a band of brothers.

The most startling picture in the show is not a Friedrich, packed as those are with metaphysical symbolism; nor is it a view of those crags, lakes and sunsets beloved of German romantics. It is by Johann Hummel (1769-1852), a professor of perspective and optics at the Berlin Academy of Art, and it depicts The Grinding of the Granite Bowl , 1832. It is an early example of the Technological Sublime, celebrating the wonder of man's power over the natural world.

The bowl in question was destined for the square in front of Schinkel's Altes Museum on the museum island in Berlin. It was cut, hollowed out, ground and polished from an enormous piece of granite found in Brandenburg. It was very consciously meant to be a world's wonder, like the gigantic basins of hard stone that were such monumental features of ancient Egypt and Rome - condensations of human skill, of incredibly laborious triumph over raw, resistant nature. But the size of this bowl and the technical challenges it posed were beyond anything from antiquity, and Hummel produced three pictures of its creation: first the enormous basin, upside down, being ground and polished in a Berlin workshop, then the job of turning it over (a wondrous spectacle to Berliners, as the erection of the Egyptian obelisk in St Peter's Square had been to Romans years before), and finally the bowl on its plinth in the Lustgarten.

With his view of the bowl in the workshop, Hummel achieved a near miracle of detailed and layered perception, recording not only the natural colours of the stone but also the hues and shapes of the workshop reflected in its surface: we see windows distorted by the curvature, and even a fragment of landscape through a window picked up on the glassy granite, every detail of the ponderous bracing that keeps the stone in place and of the geared turning apparatus. The basin becomes an apparition, rigorous in its technological truth but also surrealist in its strangeness and intensity. If Hummel had never painted another picture, this one would have assured him a small but distinct place in the history of European sensibility.

· A German Dream: Masterpieces of Romanticism is at the National Gallery of Ireland, Dublin, until January 30. Details: 00 353 1 661 5133.