John Richardson’s multitivolume “Life of Picasso” has become an institution. Mr. Richardson, who has even set up his own foundation — the John Richardson Fund for Picasso Research — has been researching the life for 25 years, and his work has certainly resulted in our more exhaustive study of the artist. “Volume I: 1881–1906” was published in 1991; “1907–1916: The Painter of Modern Life” came out in 1996. The new, third volume of his study, “The Triumphant Years, 1917–1932” (Alfred A. Knopf, 592 pages, $40) surveys the midpoint of the career of Picasso, who was born in 1881 and died in 1973.

Though this period is not Picasso’s most engaging one (we can rank it after the Blue Period, after Cubism, before “Guernica”), Mr. Richardson still knows how to deliver his subject matter. In his hands, Picasso remains the priapic visionary who translated the sexuality of Andalusia to canvas, the mystical shaman who fought evil with evil, the sadistic lover who admired the Marquis de Sade, and the superstitious clown who refused to give old clothes to the gardener for fear that “some of his genius might rub off on the wearer.”

Picasso, as Mr. Richardson explains, came from sybaritic stock: He was a “Peeping Tom like so many Andalusians,” Mr. Richardson writes, who “suffered from the atavistic misogyny toward women that supposedly lurks in the psyche of every full-blooded Andalusian male.” For an Andalusian faced with a virtuous fiancée, Mr. Richardson continues, “regular visits to a whorehouse would have been an obligatory response.” Mr. Richardson’s explanations would not exactly hold up in divorce court, indeed they can be downright silly, but his passion can come as some relief to the cooler and detached voice of much contemporary biography.

Yet for all that virility, the Picasso we find at the start of this new volume seems oddly emasculated. While his Cubist collaborator George Braque and the poet and friend Guillaume Apollinaire fought at the front, Picasso escaped to the safety of Rome. He settled into the world of Serge Diaghilev’s Ballets Russes, accompanied by the composers Erik Satie, the choreographer Leonide Massine, and the dramatist Jean Cocteau, whom Mr. Richardson belittles as a “pampered, high-society homosexual … trying to gatecrash the avant-garde.”

Picasso soon translated his accomplishments on canvas into tableaux vivants onstage. For his first production, “Parade,” he designed innovative Cubist costumes. He also drew inspiration from the Farnese Hercules in Naples, inaugurating a classical period in his own painting. Finally he fell for a petite Russian dancer, Olga Khokhlova, who became his first wife and who lifted Picasso out of his bohemian milieu.

Picasso painted the first portraits of Olga in the reverential style of the beaux arts. For this future minotaur, who would one day plunge “his monstrous, taurine penis,” as Mr. Richardson delicately puts it, into a lover’s “tumescent folds,” his visions of the early 1920s were rather staid. Olga’s transformation into a vagina dentata was still half a decade away.

Picasso never had much of a personality outside of the studio or the bedroom, and the glamorous society that surrounded him during this period clearly sucked up the artistic air. Picasso could paint remarkable work — there is “The Dance” of 1925 — but such achievements were rare, and Picasso can seem, in Richardson’s telling, almost somnambulant. Picasso’s friends, including Braque, were likewise left wondering what had become of the great artist: “Picasso’s all too evident absorption into Diaghilev’s effete world,” Richardson reports, “left Braque worried about the state of his old friend’s integrity.”

This all changed, Richardson writes, on a “propitious” evening in January 1927 — propitious for the biographer, certainly, and propitious for anyone who prefers Picasso from the waist down. While cruising for love along the boulevards of Paris, the 45-year-old artist came upon Marie-Thérèse Walter. She was 17, “an adolescent blonde with piercing, cobalt blue eyes and a precociously voluptuous body — big breasts, sturdy thighs, well-cushioned knees, and buttocks like the Callipygian Venus.” Ever the willing accomplice, Mr. Richardson is never at a loss for words when it comes to Picasso’s bed games. After a brief attempt at domestic normalcy, “For the rest of Picasso’s life sex would permeate his work almost as cubism did … As he once joked, he had an eye at the end of his penis.” Mr. Richardson excels at writing from this point of view.

Picasso’s mistress for nine years, Marie provided a counterbalance to “skinny Olga.” She encouraged an avalanche of work and inspired Picasso “to unleash his sexuality and harness it to his imagery,” which was often wickedly brutal. Picasso felt free to paint the most memorable work of the period, including “The Dream,” now in the possession of the Las Vegas hotelier Steve Wynn (who in 2006 put his elbow through it), and the whimsical “Bather with a Beach Ball,” now at the Museum of Modern Art: “In this glorious work,” Richardson writes, “Picasso has pumped Marie-Thérèse so full of pneumatic bliss that she looks ready to burst.” For Picasso this was as sweet as it got.

In his book “Modernism: The Lure of Heresy,” Peter Gay takes stock of Picasso’s achievement: “Of course, obviously, for any painter major or minor — or any poet or playwright — sexuality and aggression are indispensable raw material. What distinguishes Picasso was the animation, at times the brutality, with which he fixed love and hate on canvas and paper.”

At issue, however, is how literally we should interpret Picasso’s translation of emotion to paint. The poet and critic Roland Penrose once warned, “It would be too mechanical to read [Picasso’s] portraits as a direct paraphrase of his troubles with one mistress or another; he was too imaginative for that.” Richardson has build a great biography out of great gossip, but by looking for genius between the bedsheets, his ribald “Life” never quite credits the artist’s imagination with the autonomy it deserves.

Mr. Panero is the managing editor of the New Criterion.