In 1889, France celebrated the centennial of the French Revolution by hosting a world's fair in Paris and inaugurating, as the fair's centerpiece, Gustave Eiffel's controversial tower. One of the fair's visitors was Madeleine Lemaire, the society hostess and artist who illustrated Proust's first book, Les Plaisirs et les Jours (Pleasures and Days). She had gone to see the tower primarily for the benefit of her beloved dog Loute, to whom she talked constantly and who had, she was convinced, acquired from her an appreciation of art and architecture. Proust, who witnessed many of the conversations between Madeleine and her dog, was impressed by Loute's "extreme importance and high station." Alas, Mme Lemaire failed to record Loute's comments about the Eiffel Tower.

It was in Madeleine Lemaire's salon that Proust met the young composer Reynaldo Hahn, who became his lover for a short period and then his lifelong friend. In 1911, Proust wrote to Hahn and urged him to go ahead and choose a dog as a gift. Hahn encountered a gypsy at Versailles from whom he purchased a black, long-haired basset hound. The witty composer named the dog Zadig, after Voltaire's character, who remains puzzled by the radical rises and falls that providence has in store for him. Reynaldo and Zadig bonded quickly, as we see from a letter that he sent to Marcel: Zadig "surpasses all that human imagination could have ever conceived in love, kindness, and Bunchtism. But he loves me too much and is wounded by anything he takes as a sign of indifference. As for me, I have metamorphosed into a nanny, a nurse, a papa, a mama, and my life is nothing but an endless procession of humble and precise tasks such as cleaning Zadig's ears, examining Zadig's stool, washing Zadig, feeding Zadig."

Perhaps inspired by Madeleine Lemaire's conversations with Loute, Proust wrote to Hahn's canine companion: "My dear Zadig, I am very fond of you because you have a great deal of chasgrin and love through the same person as I have, and you could not find anyone better in the whole world." Proust then expressed his disdain for human intelligence and his wish to become a dog. Once when the distinguished writer Anatole France remarked how fond young Marcel was of "intellectual life," he replied, "I am not at all fond of things of the intelligence, but only of life and of movement." He could explain this perhaps surprising attitude to Zadig since "I have been a man and you haven't. Human intelligence only serves to replace those impressions that make you (Zadig) love and suffer by faint facsimiles that cause less grief and yield less tenderness. In the rare moments when I recapture all my affections, all my suffering, it's because my feelings are no longer based on these false ideas but on something that is the same in you and in me. And that seems to me so superior to everything else that it's only when I've become a dog again, a poor little Zadig like you, that I begin to write and books that are written like that are the only books I like."

Proust died in November 1922. Among those attending the funeral was Fernand Gregh, a close friend and fellow writer since high school days. He had brought along his little dog Flipot. As the funeral procession set out on its journey across Paris to the Proust family plot in Père-Lachaise, Flipot, who had been hiding under the hearse, ran out and disappeared into the crowd, never to be seen again by his master.