The identity of a work of art as a thing in itself, independent of representation, was on the way to general recognition when the outbreak of war in 1914 interrupted artistic life throughout most of Europe. The activities of a group of painters, writers, and musicians who sought refuge in Zürich reflected the disorientation and disillusion of the time. Dada, as the movement was called, owed much to the iconoclasm of the Cubists and to the polemical tactics of the Futurists. Nonetheless, its attack on art was fundamentally artistic; one wing of the avant-garde owed allegiance to the Dadaist tradition. As well as the need continually to attack the limits of the fine arts, it was felt important to “épater [“shock”] les bourgeois.” The Dadaists enlarged the field open to artists in three ways. They questioned the idea that some subjects were simply not relevant to painting, a question that had been hovering over art for some time, by the simple expedient of arguing that anything and everything was fair game. The repetitive and amorphous trends of Impressionism had in fact already given grounds for such a supposition. The next step was to make a reluctant public accept that any object was a work of art if an artist chose to proclaim it one. In 1914 Marcel Duchamp, the exhibitor of serial images of movement in the Section d’Or, produced a bottle rack bought in a Paris store. Better and more épatant still, he submitted a urinal to a New York exhibition under a pseudonym in 1917. Duchamp did not paint again, and this is perhaps the single Dadaist gesture that time has failed to reconcile with art. It was also the Dadaists who posed the question, if art (as Redon had realized) is not within the reach of will, how is it different from chance? Jean Arp made collages and then reliefs from random shapes obtained “according to the laws of chance.” Of all modern artists, he examined most closely the side of art akin to humour. Similarly, the Dadaists explored such elements as incongruity and dissociation, a process that led the way to Surrealism. Finally, and almost incidentally, they asked, If the presentation of movement is proper to art, why not movement itself? Viking Eggeling and Hans Richter, with animated drawings and film, made the first works in a kinetic tradition that even by the 2010s, though by then generated with digital technology, showed no sign of abating.

The painter who, more than any other, focused on incongruity—a feature that in painting involves the reinstatement of the subject, rather than its treatment, at the centre of art—was Giorgio de Chirico, an Italian born in Greece. De Chirico, rooted in the Mediterranean world, created from 1910 onward unforgettable images of its dereliction. In the immediate postwar years, he pioneered a style of emblematic, half-abstract still life called pittura metafisica (“metaphysical painting”), but by 1924, when the Surrealists began to work a similar vein of fantasy, de Chirico had changed, and in later life he disavowed his early achievement. Metaphysical painting had one unexpected sequel, the serene realism of Giorgio Morandi. Meanwhile, Kurt Schwitters in Germany developed the mediums of collage and assemblage in the new spirit. Francis Picabia, who was associated with Duchamp in the United States during the war, joined forces with the Swiss Dadaists in 1918; his contribution was an epigrammatic elegance of style. The German Max Ernst was the most resourceful pictorial technician of the movement and a continually fertile inventor.

It was in 1917 that the term Surrealism was coined, when the poet Guillaume Apollinaire described the style of the ballet Parade, for which Picasso had painted the sets, as:

a sort of sur-realism in which I see a point of departure for a series of manifestations of that New Spirit which…promises to transform arts and manners from top to bottom with universal joy.

The manifesto of the Surrealist movement, which was composed by the poet André Breton, did not appear until 1924, however. Surrealism meant different things in different people’s hands, but a common feature was absorption in the fantastic and irrational. The questions posed by Dada also preoccupied Surrealists, but for them the problem of the involuntary, fortuitous element in art, for example, was clearly open to psychological solution. The Surrealists demanded “pure psychic automatism”; the automatic drawings that the French artist André Masson made from 1925 onward and, on a more mechanical level, the frottage (“rubbing”) devices of Ernst, which added to painting the evocative effect of fortuitously dappled textures, introduced an element that flourished even more fully 20 years later. Another discovery made in the wake of Dada was similarly delayed in its full impact: Parade had been the culmination of a series of musical compositions by Erik Satie that were based on ironic quotations of popular material. In the early 1920s the Americans Stuart Davis and Man Ray made paintings out of the designs on commercial packaging, foreshadowing the Pop art of the 1950s.

The greatest achievement of Surrealist painting, however, was the invention of a new genre: fantastic realism—the prosaic, indeed quasi-photographic, rendering of the forms of fantasy and dream. The invention was the work, after de Chirico, of the Frenchman Yves Tanguy and the Spaniard Salvador Dalí. In the pictorial world of Dalí, everyday things undergo a transformation that can be almost disturbing; in that of Tanguy, forms are more suggestive than related to actual objects. A different aspect of this dream realism, one that is particularly disturbing, was shown by the Belgian René Magritte.

In the years after 1918, a mood of classical consolidation affected some painters. In Germany a “New Objectivity” (Die Neue Sachlichkeit) was imposed on Expressionism; the eventual synthesis appeared in the brutal paintings of Max Beckmann. In France the Italian-born Amedeo Modigliani, affected by the simplicity of the Romanian-born sculptor Constantin Brancusi, arrived at a delicate linear realism, the last of the great Post-Impressionist styles.

The Expressionist tradition was developed to an extreme of agonized distortion by Chaim Soutine. Another Russian-born member of the school of Paris, Marc Chagall, who had been influenced both by Cubism and the Russian avant-garde, discovered in the 1920s an individual and inconsequent vein of pictorial fancy. The sombre and devotional art of the Frenchman Georges Rouault bore the marks of his training with Gustave Moreau and as a stained-glass maker. Its crude force had been developed in the context of Fauvism, but the vision was one of refined introspection. The vigour and freedom of Fauvism was developed in the opposite direction in the decorative extrovert style of another French painter, Raoul Dufy. The classicizing trend of the 1920s had a remarkable sequel in the work of the mural painters of Mexico. One such, Diego Rivera, had learned the formal lessons of Cubism in Paris, whereas José Clemente Orozco was more dependent on the folk art of his country. Their frescoes combined grandeur with a legibility and a social awareness rare in modern art.

The greatest imaginative achievements between World Wars I and II were, however, again those of Picasso. In the years immediately following World War I, he had painted a series of solidly modeled yet oddly ironic figure pictures. Then his mood changed, and in 1925 The Three Dancers reintroduced an anarchic and convulsive quality. The ambiguities and transformations of his art, both in painting and sculpture, have an emotional character that is entirely his own, but the enlargement of the artistic language greatly influenced others. The metamorphosis of natural shape into abstracted forms that nevertheless curve and bulge with their own life, a metamorphosis initiated by Picasso, became the international style of the early 1930s. The Spaniard Joan Miró gave it his own clarity and gaiety. Biomorphic abstraction, in essence the method of Tanguy, extended the resources of Surrealism, and the Chilean Roberto Matta, who began painting in 1938, used it with dramatic effect. A poetic version of the style, rooted in an emotional response to landscape, was evolved in England by Graham Sutherland. In the later 1930s, with Guernica (1937) and other pictures, Picasso responded to specific events. About 1940 two painters in the United States, Arshile Gorky and Willem de Kooning, gave the biomorphic style a new character: relaxed, diffuse, and clear.

The development of abstract painting between the wars was comparatively slow. Paul Klee (in 1921) and Kandinsky (in 1922) gravitated to the Bauhaus, the school in Germany whose work at Weimar and later at Dessau deeply influenced architecture and design as well as basic teaching. Oskar Schlemmer, whose simplified manner paralleled the Italian Metaphysical painters, and Lyonel Feininger, an American-born painter working in a style developed from Cubism, were already teaching there. Kandinsky was concerned with refining the geometric ingredient of his work. Klee developed the poetic and fantastic elements of his art with an inconsequent fertility. The systematic purity of the Bauhaus approach survived longest in the work of Josef Albers, who moved to the United States in 1933. In 1940 Mondrian moved to New York City, and his last dynamic pictures reflect the new environment. Mondrian’s work was appreciated by only a small circle, although a similar strength of purpose with a delicate responsiveness to a broader range of forms appeared in the work of the British painter Ben Nicholson. In the 1930s some paintings were executed by artists who formed themselves into groups, such as Abstraction-Création in Paris, Unit One in London, and the Association of American Abstract Artists in New York City. The work of these groups attained wider recognition only after World War II.