“Einstein was the creative philosophical mind of the century, and I have been the creative literary mind of the century.”Few would agree with Gertrude Stein’s self-assured statement. Her stylistic experiments remain an acquired taste.Few, on the other hand, would deny that she played a key role in the promotion of modern art. At the Saturday night parties in her Paris apartment, as Woody Allen reminds us in his latest movie “Midnight in Paris,” Picasso and Matisse mingled with Hemingway, Fitzgerald and other budding talents.With her brothers Michael and Leo, Gertrude bought works of the local avant-garde well before French collectors deigned to notice them.That’s the theme of the huge exhibition “Matisse, Cezanne, Picasso -- The Adventure of the Steins,” which started in San Francisco and is now on view at the Grand Palais in Paris before traveling to New York.Thanks to a generous inheritance -- their father made a fortune with cable cars and as a developer in San Francisco -- the siblings were able to indulge in their hobbies full-time.In 1902, Leo moved to Paris to study the arts and become a painter. The next year, Gertrude, who had flunked the entrance exam at medical school, joined him. In 1904, Michael and his wife Sarah followed, renting an apartment nearby.They started collecting, yet their tastes differed. Gertrude loved Picasso whom Leo dismissed as “God-almighty rubbish.” When Leo moved to Italy, in 1914, he kept the Renoirs and Matisses, many of which he later sold to Dr. Albert C. Barnes of Philadelphia.One of the reasons for his departure was the increasingly important role Alice B. Toklas played in Gertrude’s life. Hired as a secretary, she quickly became Gertrude’s housekeeper, cook, gardener, admiring public and lover.Michael and Sarah moved, in 1928, to an ultramodern house designed by Le Corbusier in a chic suburb. In 1935, the couple returned to the U.S. Most of their collection had to be sold to cover the gambling debts of their grandson.Gertrude and Alice remained in France and, though enemy aliens and Jewish, survived the Occupation unharmed in their country house.After Gertrude’s death, in 1946, the family seized her collection in a cloak-and-dagger operation while Alice was away. Many works ended up in New York’s Museum of Modern Art.The organizers of the exhibition haven’t tried to recreate the atmosphere at the Rue de Fleurus apartment, with its highly personal mix of masterpieces and second-raters, hung in two, three or even four rows on the walls.They have eliminated the names forgotten by history and have grouped the show around the two stars, Matisse and Picasso, with 63 and 43 works respectively -- including portraits of Gertrude and Leo (by Picasso) and Michael and Sarah (by Matisse).Cezanne appears far behind in third place with just nine works. Other artists, such as Toulouse-Lautrec, Bonnard, Juan Gris and Andre Masson, play walk-on parts.Photographs, letters and books strive to convey an impression of the family’s intellectual background and artistic ambitions.You can listen to Gertrude reciting one of her repetitive poems or inspect a model of the set of “Four Saints in Three Acts,” Virgil Thomson’s plotless opera for which she wrote the libretto.What’s missing is the human side, the tensions and jealousies behind the decorum. Gertrude had a talent for quarreling with her proteges if they didn’t defer to her superior insight.Behind her back, Picasso cracked vicious jokes about her majestic girth. In “A Moveable Feast,” Hemingway’s memories of his life as an unknown writer in Paris, the writer tells an indiscreet story about Gertrude’s lovemaking and describes her as “a Roman emperor which was fine if you liked your women to look like Roman emperors.”“Matisse, Cezanne, Picasso -- L’Aventure des Stein,” which is supported by State Street Corp. (STT) and Aurel BGC, is at the Grand Palais through Jan. 16, 2012. The exhibition will be on display at the Metropolitan Museum in New York from Feb. 1 to June 3.