Masquerading as Fiction : MY OTHER LIFE.<i> By Paul Theroux (Houghton Mifflin: $24.95, 456 pp.)</i>

This is a problematic book, a tricky book, an infuriating book. It is also frequently amusing and highly absorbing. In short, a lot of fun to read but hard to penetrate at a deeper level. And it is necessary to look beneath the surface, for “My Other Life” is obviously not designed solely to entertain, well though it does that. Just what is Paul Theroux up to this time?

He tells us this is a novel. Also, that it is an “imaginary memoir.” His publisher calls it an “autobiographical novel or fictional autobiography.” It reads as if it were straightforward autobiography: first-person narrative by a writer named Paul Theroux who has written the books that we all know Paul Theroux has written and who has married, fathered two sons and otherwise lived where and how the “real” Paul Theroux has.

It does not strike me as a traditional autobiographical novel, which I’d define as a fictional rendering of some of an author’s life experiences in which certain specific details, like the author’s name and other names and incidents, have been changed. So, one is left with the suggested category of fictional autobiography, whatever that is. Is it a truly new genre? Is Theroux inaugurating a new art form as he extends the range and variousness of his literary output? Or is he simply doing whatcomes naturally, mixing memoir with might-have-been, telling his own story along with some tall tales he may wish were true?

What is particularly troublesome about this book is that Theroux is so obviously manipulating, even toying with, the reader. His “Author’s Note” states: “This is the story of a life I could have lived had things been different. . . . The fact that there are limits to serious travesty and that memory matters means that even an imagined life resembles one that was lived; yet in this I was entirely driven by my alter ego’s murmur of ‘what if?’. These characters do not exist outside this intentionally tall story . . . and the action of the narrative is vagrant in every sense. There are some names you know . . . but they too are alter egos, other hes and shes. As for the other I, the Paul Theroux who looks like me, he is just a fellow wearing a mask. . . . .”

But in fact, the book does the exact opposite of what has just been promised: The “fictional” Paul Theroux, like the real one, hails from Medford, Mass., serves with the Peace Corps, marries an Englishwoman in Africa and fathers two children, teaches and writes in Singapore and then comes to London before divorcing his wife and moving back to the United States. He claims the man is fiction and the mask is real, but isn’t it the other way round?

W. Somerset Maugham once said that fact and fiction were so inextricably mixed in his stories that he no longer knew which was which. Theroux, however, seems very much in control of his material and I have not the slightest doubt that he knows which parts of this book really happened to him and which ones he invented. The rub is that he isn’t letting the reader know which is which.

But does this, after all, matter to the reader? Can he not simply enjoy this book for its many pleasures: its passages of lyrically beautiful prose, its sharply etched social portraiture, its skillful evocation of emotions? I suppose so, but again Theroux seems to have gone to considerable trouble to ensure that the reader play the game he has set up for him and perhaps originally for himself. Indeed, this book gives the distinct impression of having been written as a kind of one-man chess game in the first place.

“My Other Life” contains savage portraits of real-life characters, some safely dead , like Anthony Burgess, and thus unable to dispute Theroux’s version of events. Others, like Queen Elizabeth II and the Duke of Edinburgh, while undoubtedly alive, find themselves by virtue of their position equally unable to dispute an unflattering and even damaging portrait of themselves in what was apparently a private situation.

I single out these particular portraits because they have already, thanks to serialization of parts of this novel in The New Yorker, elicited great controversy. Burgess may be dead, but Theroux’s ex-wife is not and she wrote an irate letter to the New Yorker not only challenging the accuracy of the Burgess incident but denying that this dinner party at the Theroux home in London ever took place. (The upshot of this seems to have been a change in the first name of the author’s wife in the novel version--a pretty lame equivocation, I’d say.) The author’s ex-wife was not the only reader naive enough to resent fiction masquerading as self-refuting “faction”: The incident featuring the queen was likewise taken to be reportage, judging by the press’ reaction to certain racially insensitive remarks she (oops, her “alter-ego”) is alleged to have uttered about the hapless premier of one of her more remote dominions.

It must, in fairness, be noted that Theroux is able to carry off his brutally satiric portraits of others because he does not spare himself. Readers familiar with his travel writing will recognize the “Paul Theroux” in this book as the wry, detached persona who rode the trains of Asia or the boats of the Mediterranean, but they will also be exposed to a searching portrait of a more tormented, angry, acrid and unpleasant character than has hitherto been presented.

A writer of Theroux’s 55 years came of age in the era in which literary studies were dominated by the New Criticism, a movement that sternly enjoined that attention be devoted solely to the text without reference to biographical or historical background. I am tempted to think that “My Other Life” is Theroux’s revenge upon the New Critics: a book that demands to be read biographically--which is written in such a way that only a reader from Mars might possibly read it without making such references--but which also coyly declares itself a denizen of the sacrosanct domain of imaginative literature.

It is unfortunate that Theroux, an acknowledged master of travel writing, has chosen to write a book that travels around the edges of his protagonist (or self) rather than voyaging into the heart of darkness that seems to lurk just offstage in the character, fictive or real-life, of Paul Theroux.