During this period of isolation, from the late 1870s to the early ’90s, Cézanne developed his mature style. His landscapes from this period, such as The Sea at L’Estaque (1878–79), are perhaps the first masterpieces of the mature Cézanne. These landscapes contain compositions of grand and calm horizontals in which the even up-and-down strokes create a clean prismatic effect and an implacable blue sea spreads wide across the canvases. Like all his mature landscapes, these paintings have the exciting and radically new quality of simultaneously representing deep space and flat design. Cézanne knew well how to portray solidity and depth; his method was that used by the Impressionists to indicate form. In his own words, “I seek to render perspective only through colour.” The painter’s intelligence and eye were able to strip away that which was diffuse and superimposed in the view of a given mass, in order to analyze its constituent elements. In works such as these, he chose to rediscover a more substantial reality of simple forms behind the glimmering veil of appearances: “Everything in Nature is modeled after the sphere, the cone, and the cylinder. One must learn to paint from these simple figures.” At the same time, such pictures present shimmering harmonies of color that can be seen as totally flat designs, without depth. Other striking landscapes from this period are the prismatic landscapes of Gardanne (The Mills of Gardanne, c. 1885) and the series of monumental compositions in which Mont Sainte-Victoire near Aix becomes a mythical presence.

Cézanne was to use essentially the same approach in his portraits. Some of the best known are Madame Cézanne in a Yellow Armchair (1890–94), Woman with Coffee-Pot (1890–94), and The Card Players (1890–92). This last painting portrays a theme that Cézanne treated in five different versions. Except for the card-player paintings, in which the sober dignity of the men is well expressed, there is no attempt in Cézanne’s portraits to hint at the sitter’s character. In most cases he treats the background with the same care as the subject and often violently distorts facial color to bring it in harmony with the total composition. Cézanne also applied his principles of representation to his extraordinary still lifes, of which he painted more than 200. He organized them as though they were architectural drawings, giving the most familiar objects significance and force through the intensity of the color and the essential simplicity of the form.

Full of the intensity of feeling aroused by his surroundings, Cézanne’s art was also deeply cerebral, a conscious search for intellectual solutions to problems of representation. Although he had great admiration for many other painters, he disagreed with the objectives of all but himself; painters who narrated events, as did the Romantics and the Old Masters, and painters who only represented nature—as did the Impressionists—seemed to him to lack a standard of purpose that only his own art possessed. At the same time, he was not a truly abstract painter, for the ideas of structure that he wished to express were about reality, not design. In this, he was the major source of inspiration for the Cubist painters.

After his father’s death in 1886, Cézanne became financially independent. He had married Marie-Hortense six months earlier, and, after a year in Paris in 1888, Marie-Hortense and their son moved there permanently. Cézanne himself then settled in Aix except for a few visits to the capital, to Fontainebleau, to Jura in Switzerland, and to the home of Monet in Giverny, where he met the sculptor Auguste Rodin. In 1895 the art dealer Ambroise Vollard set up the first one-man exhibition of Cézanne’s work (more than 100 canvases), but, although young artists and some art lovers were beginning to show enthusiasm for his painting, the public remained unreceptive.