READERS TAKE A gleeful interest in the mess most writers make of their private lives, and a full documentation of financial irresponsibility, alcoholism, sexual peculiarity and general bitchiness seems the current prerequisite to the final acceptance of a modern master. This assures readers that the every worst about an author is already known and published, and that even if they can't write like Virginia Woolf at least they can enjoy sex. Undergoing this treatment at the moment are Malcolm Lowry, George Orwell, W.H. Auden, and, of course, Virginia Woolf. Occasionally a writer's private life is so juicy that even if he or she is not being prepared for deification, a biography of this sort will appear. A review of the contents of Harold Nicolson's Portrait of a Marriage can easily give the impression that it is just another of these misdirected books.

After all, the revelation that Vita Sackville-West was a bisexual was not expected to be among the greater literary events of 1973. But gossip of this sort is only a trap Nicolson set to make sure of an audience--the real purpose of the book is to propose a change in our expectations of marriage. Nicolson, after an anguished divorce, recommends a form of marriage consisting of mutual respect and affection but not sexual exclusivity. Sexual attraction and even compatibility become unnecessary for a "successful" marriage. The proof he offers is the life of his own parents--a bizarre, disturbing, and finally convincing story of as unpromising a marriage as there ever was.

Vita Sackville-West, whose memoirs make up about half the book, grew up in an Elizabethan manor house larger, she liked to point out, than most palaces; if she'd been a man, she would have inherited it along with one of England's oldest titles. Instead, she became a writer and served as the model for Virginia Woolf's amazing Orlando, who danced his way through history and changed sex with the centuries. Harold Nicolson, who married Vita, was an equally blue-blooded dilettante with dozens of books to his credit. Together, they shared an aversion to the middle-class, Jews, and members of the opposite sex. Each was predominantly homosexual, and after the birth of their second son agreed to eliminate sex from their relationship.

At first the marriage seemed to break apart--Vita fled to France with her lover and Harold resorted to the British Navy to bring her back. But on the basis of mutual tolerance, the two settled down to a marriage their son describes as idyllic, whose sine qua non was the absolute freedom of both partners to enjoy sexual adventures with other men and women. Even when their outside infatuations were deepest, they couldn't think of each other merely as "friends;" of course they could not think of each other as lovers; they could only be described as husband and wife.

The sexless marriage that resulted takes the short-lived nature of sexual attraction into account and makes infidelity the expected element of variety instead of the shocking, common thing it is now. marriage should stop being an attempt to shut out all the world but one, Nicolson contends; the alternative is a nation of divorcees.

THE SUGAR-COATING for this polemic is some of the juiciest literary gossip to come out of the Bloomsbury boom, which seems to derive much of its momentum from the revelation, at well-spaced intervals, of its members' sexual habits. Bloomsbury, was, we know now, stranger than we could have imagined. Each month for the last year or so has brought a new book calculated to shock, titillate, and endear these brilliant perverts to out hearts. Lytton Strachey's fascination with the eroticism of the ear, John Maynard Keynes's penchant for the hand, and G. Lowes Dickinson's boot fetishism have all been the subject of recent studies. At the center of it all stands Virginia Woolf, whose sexuality threatens to become a serious literary question. Her nephew Quentin Bell, in his otherwise admirable biography, claimed she was frigid; now Nicolson publishes fairly conclusive evidence to the contrary. This may be one of those questions of literary history--such as how many children Lady Macbeth had or how long it took Douglas Bush to memorize Paradise Lost--that we may never care to solve. But a lot of people, to judge from sales, are interested, and soon we will know more about Bloomsbury than any comparable group. Which would be too bad, since a superabundance of biography often leads to hasty literary judgments. Bloomsbury lived half-posing for its portrait, but scholars should not be too quick to oblige.

Aside from her role as Vita's lover, Virginia Woolf is an important figure in Portrait of a Marriage because she came very close to embarking on a marriage exactly like the Nicolsons'. She considered, and at one point accepted, an offer of marriage from Lytton Strachey, which would have produced precisely the same sexual orientation. In the end Lytton chickened out, but the episode proves that this kind of marriage is not as irrelevant an accident as it might seem, but an increasingly major alternative to the problems that all the sex researchers of the sixties have done little to solve.

A hostile reader could easily see the Nicolson marriage as a sham. Two wealthy, upper-class homosexuals make the mistake of marrying and then spend the next half-century trying to keep up appearances. Judgment hinges on an evaluation of Vita's sincerity and the objectivity of her son. If they deluded themselves, this Portrait of a Marriage is worthless. Most of the other books produced by the family are more glib and polished--but whether or not they will be remembered depends on the long-run verdict on the free, civilized form of marriage these two proper Britons pioneered. Whether they did so as a last fling of aristocratic contempt for convention or as a conscious attempt to construct a new set of rules for marriage doesn't matter much. They were brave enough to stake their feelings on their solution, and to leave the rest--ironically enough--to their children.