Picasso was a lover whose love enfolded hate. That solitary frightener, the most fecund of the masters, knew himself to be a sort of monster.

His influence was crushing. His creature was the Minotaur of Mediterranean myth, a thickly muscled demigod, devourer of beauties, half man and half bull.

He broke women, he broke forms, he broke artists. By the thousands they destroyed themselves attempting to follow his example. "The bull," he once explained, "is bestiality and darkness." Picasso knew its force.

"Pablo Picasso: A Retrospective" today begins a four-month run at the Museum of Modern Art. This shattering exhibit, which fills the whole museum, is both awesome and appalling. It teases, astonishes, doubles back upon itself. It is never boring, and yet it does not cheer. Some terrible impatience, something harsh and heavy, is hiding at the heat of this labyrinthine show.

There were, it sometimes seems, hundereds of Picassos -- the prodigy, the Catalan, the painter of the blues, the nationalist, the lover, the classicist, the Cubist, the sculptor and the wit. No small show could capture a spirit to inventive. This one includes 1,000 objects, and it needs them all.

The master, as we seek him in the maze that is his work, lunges, feints and vanishes, and then strikes again.The Minotaur of Crete was a creature of Poseidon, and equally elusive. Picasso, like the monster, had within his power something of the fluid power of the sea.

Had his heart been lighter, had he loved the ugly less, Picasso might have seemed a shape-changer, a sprite. His talent was prodigious. The freedom of his drawing -- and drawing rules his art -- is beyond our comprehension. Surely he was blessed. But also he was cursed.

"A picture," said Picasso, "is a sum of destructions." Something in his makeup, some hostility, some roughness, bound him to the battle, kept his soul at war.

He fought his father first, as later he would fight Franco and perspective, his public's expectations, his children and his wives. Picasso could not rest.

Halfway through his show -- after seeing him devour Gauguin and Toulouse-Lautrec, after watching him discard the Blue Period, the Rose Period, after the great march toward "Les Demoiselles d'Avignon" and the Cubism beyond -- the viewer starts to yearn for an episode of peace. But peace does not come.

Some great artists in old age seem to soar toward God -- think of Titian's grace, or of old Matisse swimming in pure color. But there is no such growing calm in Picasso's art. Color soothes the soul, but Picasso was no colorist. Nor were his pictures polished. They were hasty, rough.

In the last years of his life, hugely rich, approaching 90, Picasso battled Delacroix, Velazquez and other longdead masters, as if jostling for position in the history of art. He stopped dating his pictures; he did not leave a will. Earthy to the end, he did not want to die.

He was born in 1881 in Malaga in southern Spain, the child of a painter. At 13, Picasso drew with some authority and grace, so the story goes, that his discouraged father chose to give up art. At 14, young Picasso had acquired all the skills of the academician. Later he would say that he spent his lifetime learning how to draw as freely as a child. Of the nearly 50 galleries now filled with Picassos at the Museum of Modern Art, none is more astounding than the one of juvenilia with which the show begins.

Picasso used to say that he put into his paintings "all the things I like."

He liked his handsome, dark-eyed face. He liked the unexpected. He liked women most of all. And what he liked he loathed.

The embrace and the attack are blended in his art. Everywhere he reconciles things that ought to clash -- anger and affection, tradition and revolt, the sweet and the bizarre, two and three dimensions (he invented the collage; "Still Life with Chair Caning," his first one, dated 1912, is included in this show).

His art feeds our anxieties; a sense of enforced truce is one of the few constants in this shifting show.

Although it includes unfamiliar objects, it contains few surprises. We know Picasso well. We grew up on his art, but the shocks that we once felt have, by now, faded into numbness. Though we were taught to chop his art into discrete chapters -- the Rose Period, the Blue Period, one after another -- here, instead, we see it continuum, its flow.

Consider, for example, his portraits of himself. The first one that we see here was done in 1896, when he was but 15. He made the most recent some 70 years later. When we meet him first, he is a man of beauty; he flirts with the viewer, his dark eyes seem to burn. His face, by 1906, had smoothed into a mask. By 1933, its nostrils had begun to flare, and it had grown its horns.

Rembrandt was the last of the European masters to leave to posterity self-portraits of such power. But while Rembrandt in his pictures bares his rightly judging heart, Picasso bares his lusts. Sometimes he's the lover, sometimes he's the bull. There are dozens of self-portraits here. A sexual energy burns in every one.

"Art," he said, "is never chaste," and surely his is not. It seethes with sensuality. We know him as a radical, daring, unpredictable. We honor his inventions, his combining of materials, his shattering of space. Picasso sometimes seems to be the most modern of the modernists -- but there is something ancient, something passionate and pagan, throbbing at the center of Picasso's art.

Somewhere in his gene line are the cave painters of Spain, the bull dancers of Crete, the carvers of the Cyclades. And in every work of art here, no matter what its style, Picasso serves, as they do, the fertile and ferocious Mediterranean muse.

Daniel-Henry Kahnweiler, the painter's friend and dealer, once described Picasso's work as "fanatically autobiographical," and it is true that portraits of the artist's wives and lovers fill the New York show.

Fernande is here, and Olga, the dancer of the Diaghilev's ballet, and Dora and Francoise, and blond Marie-Therese Walter, the loveliest of all. Picasso started painting the women in his life soon as he reached puberty, and he never stopped. In 1963, already in his 80s, he made at least 160 portraits of Jacqueline, his wife.

Though we see his women, we never grow to know them. The Minotaur, imprisoned in his labyrinth, devoured youths and maidens. Picasso, too, uses beauties as food to fuel his art. Restlessly he prowls. His styles shift, the bodies and the faces change, but for more than 70 years the motive of the painter remains eerily the same -- to portray the female in all her guises.

In Picasso's first large oil, made when he was just 15 (and, like many of his early works, borrowed for this show from the Museo Picasso, Barcelona) we see innocence in white, kneeling at the altar while the artist's father, bearded and dressed in black, stands next to her on guard. In "Science and Charity," Picasso's second major work (1897), we see her in three aspects, as nun, dying mohter, and little daughter too. This Victorian tear-jerker earned the young Picasso a gold medal at a home-town show.

By 1901 Picasso, by this time in Paris, has begun to paint her as the grinning harlot, the woman of the night. Soon her body thickens. By 1906 her once-smiling face has become a mask. The painter has, by now, discovered African tribal sculpture and ancient Iberian carvings dug up in Osuna. In early 1907 we see him approaching what may be his grandest work, "Les Demoiselles d'Avignon."

The picture provoked cubism. Earlier Picasso, fleeing from impressionism, had given to his figures near-Egyptian solidity. Now, in "Les Demoiselles," he breaks things down again.

We have been taught to read this extradordinary work, with its flatnesses, its facets, its plural points of view, as a step toward cubism, and it is surely that -- but it also is a portrait of five Barcelona whores.

Even when he paints something as conventional as a "Still Life with Pitcher and Apples" (1919), the spirit of the feminine -- her nourishing, her roundness -- is present in his art.

In the master's wondrous "Girl Before a Mirror" (1932; Marie-Therese Walter is his model here) Venus is his subject. Sometimes she's a flower, as in a 1946 portrait of Francoise Gilot. Sometimes she's an insect; in his "Seated Bather" (1930), she snarls at the viewer with the saw-toothed mouth of a monstrous praying mantis. In the works of 1910 she is splintered into planes; in 1932, she seems made of balloons. Her body changes forms, her features rearrange themselves, but she is always there.

In another apsect, in the guise of Aridne, she gave to Theseus of Athens the simple ball of string with which that valiant hero, the slayer of the Minotaur, at last found his way from the monster's lair.

Palettes gray and blue and rose, masks and cubist shatterings, harlequins and doves, horses, children, blue guitars, and a hundred different styles somehow distract the viewer from the heavy truth that lies at the center of Picasso's art.

The string is worth remembering. The viewer who remembers the way that has come will discover why Picasso knew himself to be a monster of a sort. There is in Picasso's work something bestial, menacing. His art was not cerebral. He painted from his guts.

No Picasso retrospective as wideranging as this one is likely to be seen in America again. "Guernica," for instance will soon return to Spain, probably to the Prado. A third of the objects here, those drawn from the estate, will soon be installed in a new Picasso museum in Paris. Once there they will not travel to American again. The Picasso exhibition -- organized and beautifully selected by William Rubin and Dominique Bozo -- celebrates the 50th anniversary of the Museum of Modern Art.

Fifty-six museums have lent works to the show. IBM has given some $400,000 with which to pay the bills. The objects on display, more than half of which have not been seen in America before, have been installed chronologically so that the patient viewer, moving from the garden up to the third floor, can retrace the growth of Picasso's art.

Admission is by tickets only, $4.50 for adults, $2.50 for students, 75 cents for senior citizens and those under 16. Tickets are being sold through Ticketron and at the museum. This exhilarating exhibition closes Sept. 16.