James's insight into "ladies" didn't come just from reading. He involved himself with two advanced women. One was his cousin Minny Temple, whose "psychologic" approach to character James took up, and whose restless search for a plot on a par with her promise provided a source for Isabel Archer (in The Portrait) and Milly Theale (in The Wings of the Dove). After Minny Temple died at the age of 24, James told his brother that he had hoped to take the lead in a masculine way, but in fact he preferred to possess Minny in memory and art: "locked", he exulted, "within the crystal walls of the past".
His feeling for new women did not extend to women writers. An early review snubs Louisa May Alcott for her "precocious" American girl. Of course, this was the ground he wished to colonise.
In 1887 he disparaged a best-selling writer called Constance Fenimore Woolson. She was a great-niece of James Fenimore Cooper - privately, for they were "intimate friends", James called her "Fenimore", fascinated by her connection with fame on a scale which lay as yet beyond his reach. Her popular heroines manifest native grit on the frontiers of existence, but James slights them for their "shipwrecked" air. His subtlest ploy is to ignore her best work: three innovative stories of artists, a vein in which James was to become pre-eminent. He took from her ideas for two of his most brilliant tales, "The Figure in the Carpet" and "The Beast in the Jungle".
Minny and Fenimore differed from the helpless muse. Minny was more familiar with James than anyone would be again. "If you were not my cousin, I would ask you to marry me," she said in 1869, reminding him "that of all the princes and princesses . . . who now seek your society, none of them love you half so well as I do." Fenimore took her stand in stories that recreate him as a beguiling authority who proves a destroyer.
James had a genius for the interior life: its hidden motives and the untested potentialities of women. To know the unseen, he depended on living beings. "I want fire," he begged Morton Fullerton in 1900: not sex, but "a Light on your Life".
In 1901, when Minny's niece Rosina would not yield her secret "self" in the run-up to The Wings of the Dove, James spelt out a fantasy in which she can't escape. Seated in his box, he trains his glass on her. "If opera glasses could penetrate & hypnotise, I could drag her down over the front of the box & jerk her . . . into my arms."
Sex wasn't non-existent; it was transformed as desire to possess souls. His spectatorial posture - immortalised in Sargent's portrait of James at 70 - obscured his involvements: the plan he shared with Minny of meeting "romantically" in Rome, and the expatriate "home" he shared with Fenimore for 14 years before her mysterious death in 1894.
Genius appears to soar above such ties, but this is romantic myth, perpetuated by James in the rarefied solitude of a writer in his tale "The Private Life". Genius, though, can't emerge in a void. The lives of two women who "fired" James tell a truer story of what we might call collaboration.
Lyndall Gordon is the author of `A Private Life of Henry James: two women and his art' (Chatto & Windus, pounds 20)