In 1895, after 30 years of painting the reclusive Frenchman Paul Cezanne had a one-man show, his first. He was 56 years old. He had 11 years to live. More than 120 late Cezannes - watercolors, oils, dozens of his portraits, whole walls of his still lifes, 20 differing views of his beloved Mont Sainte-Victore - have been assembled by the Museum of Modern Art. Prophetic yet traditional, clear-sighted yet anxious, these are among the most revered - because most deeply felt- painting of our age.

Cezanne did not show his talent early. Unlike, say, Picasso, he did have the "touch." Cezanne had to grope. Yet he taught himself to see as no man had seen before.

"I must tell you," Cezanne wrote his son six weeks before his death, "that as a painter I am becoming more clear-sighted before nature, but with me the realization of my sensations is always painful. I cannot attain the intensity that unfolds before my senses." We can see Czeanne's integrity. We are more moved by his ethics than we are by his gifts.

A mountain in his distance, apples on a table, rocks and trees and bathers - throughout the last years of his life Cezanne returned, as if commanded, to the same motifs. Yet he shunned repetition. He "never ceased declaring that he was not making pictures, he was searching for a technique." One cannot trace his search in isolated paintings. One must see his pictures side by side, as they are displayed here.

"Cezanne: The Late Work" is a magnificent exhibit. There has never been a show of late Cezannes as complete as this one, and there may never be another. It closes Jan. 3.

In the history of modern art, no painter looms as large as Cezanne. Of all the attributes of art, it is originality that our century most values. "Cezanne," said Henri Matisse, "is the father of us all."

Because Cubism, Fauvism, all of modern paintings, from Braque to Jasper Johns, flows from his accomplishment, it is Cezanne the prophet, the exemplary inventor, that we tend to honor most. This show adjusts that view.

The cerebral painter Jasper Johns (whose retrospective is on view nearby at the Whitney) suffers from Cezanne much as color painter Kenneth Noland, whose art is now in Washington, suffers from the current exhibition of Matisse. The Americans start from scratch. Newness is their aim. The Frenchman, too, reached out for modernity, but in doing so they saw no need to let go of the past.

The cut-outs of Matisse (today is their last day at the National Gallery of Art) are as full of Mediterranean myths as they are prophetic of color field painting. Though his pictures sparked a revolution, Cezanne was a conservation. He said he sought an art as solid and as lasting as that of the museums. Even in his 60s, he would repair to the Louvre to copy the Old Masters. His late works are more than radical. They summarize - and culminate - 400 years of art.

He would not paint abstractions.He condemned the "flat" and patterned pictures of Gauguin.("Gauguin," he said, "was not a painter. He only made Chinese pictures.") "Painters," said Cezanne, "must devot themselves entirely to the study of nature." He did not make up his pictures (except for the "Bathers"). He at all times sought to represent the "sensations" he received from the solid things before his eyes.

He was painting, for the thousandth time, the countryside near Aix when, on Oct. 15, 1906, a violent rainstrom drenched him. He died a few days later.

The Romantics painted dreams, Cezanne painted nature. The Impressionists, his contemporaries, sought to paint effects.Cezanne painted things. He had, as Lawrence Gowing observes in the catalog, a "fiercely prehensile eye."

Painters, for 400 years, had obeyed the laws of Renaissance perspective. Cezanne dared to break them. Painting in perspective was like furnishing a doll house. The picture was a window. It looked into a box, an empty cube of space, which the artist filled, as he saw fit, with columns, trees, madonnas. The positions of these objects were determined by the floor plan, their shapes were sharply outlined, their volumes were revealed by the shadows that they cast and by the way they caught the light.

Cezanne invented a new way of painting solid things in space. The tables in his still lifes are, by the old rules, wrong. Their tops tilt and their edges zoom off in odd directions. The pears and apples that we see do not take their roundness from outlines or from shadows. Cezanne's forms are built of colors, not of shaded lights and darks.

His forms, and not his forms alone, but all their interactions, and the air, he space between them, are built of colored patches. "His method was remarkable, absolutely different from the usual way and extremely complicated," wrote Emile Bernard who had watched Cezanne at work in 1904. "he began on the shadow with a single patch, which he then overlapped with a second, and a third, until these patches, hinging one to another like screens, not only colored the object but molded its form . . . He interpreted rahter than copied what he sas. His vision was much more in his brain than in his eye."

Viewed singly, pulled from context, the "color patches" of Cezanne - that block of brown, that splotch of green - seem arbitrary, shapeless. But when brought into harmony - and for that there was no system - the whole picture looks in place.

Cezanne is far more than a scientist of seeing.What strikes us most before these works is not technique, but feeling. His pictures are related, yet no two are alike.

The figure in his portraits, unlike those of Eakins, are not in sharp focus. Their faces may be mask-like, they are doing nothing special, yet one hesitates to analyze their brushstrokes or their colors. These are people, not just paint. We see them with our hearts. Cezanne in these late portraits is nearer to Rembrandt than to Braque.

"What forces our interest," said Picasso, "is Cezanne's anxiety." The technique had been mastered, but technique was not enough. Cezanne sought seamless paintings. "There mustn't be a single link too loose," he said, "not a crevice through which may escape the emotion, the light, the truth." He peered into the heart of things, seeking there a harmony to which there were no short-cuts. In each of these late pictures we feel the painter groping, painfully, heroically, to discover it afresh.

"Cezanne: The Late Work" was organized by professor s John Rewald and Theordore Reff and by William rubin of the museum's staff. Rubin also edited the superb 416-page catalog."Cezanne: The Late Work" will, in slightly different form, visit the Museum of Fine Arts, Houston, and the Grand Palais in Paris after closing in New York.