Writer Christopher Isherwood, who died Saturday at 81 of cancer, was one of the last "wild boys" -- that's what Leslie Fiedler called them -- who came down from Oxford and Cambridge "crying the names of Freud, Marx and Kierkegaard as battle slogans."

Some others were W.H. Auden, Stephen Spender, Edward Upward, C. Day Lewis and Louis MacNeice. Most were wellborn and educated in Britain's best private schools, and they believed in themselves at an early age. They had ideas about what had gone wrong with the world -- the First World War was within experience -- and they committed themselves to making something better, usually by taking up leftist political causes or finding answers through art. They were democratic aristocrats. Their political effect was negligible; they were too independent to organize or be organized. They still saw the world through the eyes of the classes, not the masses, anyway. But they were destined to create books and plays and poems that would show us ourselves in new ways and with new language.

They began as young men with social philosophies -- Isherwood was a pacifist all his life. They ended as writers whose social contribution was art: the product of solitude. Isherwood was their most courageous.

The breadth of Christopher Isherwood's writing was such that he seemed to have been born to the craft. Indeed, his mother and father both wrote extremely well, as he showed us in "Kathleen and Frank." Isherwood published novels, plays, poetry and travel books by the time he was in his midthirties, some of them with W.H. Auden, to whom he was bonded early. He translated Baudelaire's "Intimate Journals" at the age of 26. After he came to the United States and settled in Hollywood to write fiction and films, he became interested in the Vedanta movement and translated four classics of Hindu philosophy, including the Bhagavad-Gita.

Christopher Isherwood wrote about 15 books during his lifetime, but his fame rests on the series of stories and novels that grew out of his four years in Berlin during the 1930s -- "The Last of Mr. Norris" and "Goodbye to Berlin" -- and that became "I Am a Camera" when dramatized in 1951 by John Van Druten and the musical "Cabaret" much later. This is the work in which Sally Bowles, the beautiful and clever, but modestly talented, cabaret artist appeared. She was the bright spot on a grim horizon as Hitler began to rise to power, and it is almost impossible to think of Germany immediately after the Weimar Republic without remembering her. We owe her to Isherwood.

But I suspect his contribution to the craft of fiction and to the legacy we call literature is something much larger. It was in these Berlin works and several later novels that Isherwood began -- he was among the first and the most successful at it -- mixing up fiction and fact, pretense and reality, in such a way that his work took on a quasi-documentary quality.

The Berlin works involved a fictive character bearing the author's name, and we saw events as if on the edge of history. When Isherwood published "Down There on a Visit" in 1962, this candid autobiographical story of a man in search of himself was also about a figure named Christopher. Truman Capote may have claimed to have invented something called the nonfiction novel, but Christopher Isherwood was interweaving fictive reconstruction and factual observance 30 years before "In Cold Blood."

But it seems to me more important that Isherwood very early, before it became fashionable, combined this marriage of fact and fiction with the investigation of what life as a homosexual is truly like. He did it most effectively in his 1962 novel "A Single Man" and continued the process in "Christopher and His Kind" in 1976. While "Christopher and His Kind" is an account of his life and that of his male lover over a 10-year period, "A Single Man" deals with one poignant day in the life of a 58-year-old homosexual professor in a California university after the death of a man he loved. (Isherwood taught at a number of California colleges.)

Anthony Burgess later said "A Single Man" was one of the best novels in English written since 1939. Surely it is one of the best novels ever written about loneliness. The feelings in the novel are delicate but deep. The anguish the narrator experiences is the pain that knows no sex. Yet it is the anguish of one who is outside, alone, threatening no one but perceived by society to be a threat to all.

What Christopher Isherwood did was to fuse art and life. The best always do. It was his life, finally, that became his art. About 10 years ago, he said, "I thought I couldn't go into it . . . It's so much more than 'homosexuality.' " What he showed us was that being homosexual also means feeling everything. It was something we needed to know.