In 1863 the Salon jury in Paris rejected so many paintings that artists protested loudly. Emperor Napoleon III responded by ordering a separate exhibition of rejected works, the Salon des Refusés, so the public could judge for itself. Crowds came, many of them to laugh. The most mocked picture was Édouard Manet's Luncheon on the Grass, which showed a naked woman picnicking with two clothed modern men and looking straight at the viewer. Within fifty years, the system that had judged it would lose its authority, and the idea that art must constantly break with the past would become a tradition of its own.

Impressionism

In 1874 a group of painters tired of the Salon held their own independent exhibition in Paris. Among them were Claude Monet, Pierre-Auguste Renoir, Edgar Degas, Camille Pissarro and Berthe Morisot. The name Impressionism came from a critic who mocked Monet's painting Impression, Sunrise; Louis Leroy's satirical review suggested that wallpaper in its early stages was more finished. The painters adopted the label.

The Impressionists tried to capture fleeting effects of light and atmosphere, often painting outdoors with quick, visible brushstrokes. New tubes of ready-mixed paint made working outside easier. Their subjects were modern: railway stations, boulevards, cafés, suburban riverbanks, women at home. Morisot and the American Mary Cassatt, kept by custom out of many public places their male colleagues painted freely, made the private world of women's homes their subject, turning a constraint into a strength.

Influence also flowed from outside Europe. After Japan opened its ports to Western trade in the 1850s, woodblock prints arrived in Paris in large numbers. Japonisme was the European enthusiasm for Japanese art, whose flat color, bold outlines and cropped views shaped painters such as Degas, Cassatt and Vincent van Gogh, who copied prints by Hiroshige in oil.

Breaking the picture apart

Paul Cézanne, working in the south of France, built landscapes and still lifes out of blocks of color, treating nature as a structure to be rebuilt on canvas. Pablo Picasso and Georges Braque pushed this much further. Picasso's Les Demoiselles d'Avignon of 1907 shows five nude women with angular bodies; two faces resemble African masks, which Picasso had seen in a Paris ethnographic museum. Admirers then and since called it a revolution, while some scholars criticize how European artists borrowed African forms while knowing little about the people who made them.

From around 1908 Picasso and Braque developed Cubism. Cubism showed objects from several viewpoints at once, broken into flat, overlapping planes. A guitar or a face might be seen from front and side simultaneously, as if the painter had walked around it. They also glued newspaper and wallpaper onto canvases, inventing collage as a fine art technique. In New York, Marcel Duchamp went further with what he called readymades: a readymade was an ordinary manufactured object chosen by an artist and presented as art.

Abstraction and the machine age

Some artists abandoned recognizable subjects altogether. The Swedish painter Hilma af Klint made large abstract paintings from 1906, though she kept them private. Wassily Kandinsky, working in Munich around 1911, argued that color and form could affect the soul as directly as music. In 1915 in Petrograd, Kazimir Malevich exhibited Black Square, a black square on a white ground. Malevich hung Black Square high across a corner, the place where Russian homes traditionally hung a sacred image, declaring a new spiritual art of pure feeling.

Other movements embraced speed and machines. The Italian poet Filippo Tommaso Marinetti published the Futurist Manifesto in 1909, declaring that "a roaring car that seems to ride on grapeshot is more beautiful than the Victory of Samothrace." Futurism glorified speed, machines and the modern city, and also praised war; the manifesto called war the world's only hygiene. Several Futurists later supported Mussolini's Fascism, a reminder that a movement can be artistically daring and politically ugly at once.

Worked example: a urinal called Fountain

In 1917 Marcel Duchamp bought a standard porcelain urinal from a plumbing supplier in New York, turned it on its back, signed it "R. Mutt 1917" and submitted it under that false name to the first exhibition of the Society of Independent Artists. The society had promised to show any work whose artist paid the fee. Even so, the urinal was kept out of the show. The original was lost; it survives in a photograph by Alfred Stieglitz and in later replicas Duchamp approved.

Form: a smooth white curved object, glossy, symmetrical, set flat so that it looks oddly like a seated figure or a veiled head. Its shape, viewed this way, is surprisingly elegant.

Content and context: this was a readymade, and Duchamp had not made it with his hands. A short defense in a magazine he helped run argued that what mattered was that the artist chose it, gave it a new title and point of view, and so created a new thought for that object. After Fountain, the question "is this art?" became part of art itself. A 2004 poll of 500 art world professionals, run alongside the British Turner Prize, named it the most influential modern artwork. Whether that is a triumph or a symptom is still argued.