Alexander Solzhenitsyn was born in 1918, in Russia's southern Caucasus region , into a family of mixed backgrounds that became notable for its ''tradition of subbornness and independence'' - and also for its persistent, variegated back luck. His father, from peasant farming stock, was an intelligent and ambitious army officer who died tragically, in a hunting accident, just before his son was born. Solzhenitsyn's mother came from a wealthy family and found herself, in the wake of the 1917 Bolshevik Revolution, in constant danger of persecution by the new regime: Her life became an uphill struggle to support her young son and a series of temporary stays with relatives and sympathetic friends while seeking a permanent home. Thus were rootlessness and insecurity impressed upon - indeed, all but bred into - the young Solzhenitsyn.
Mother and son finally settled in the market town of Rostov, where young Alexander dedicated himself to demanding literary projects (he had begun, we learn from Michael Scammell's current biography, ''to write systematically and at unusual length from the age of nine'') and to the Communist Party's Young Pioneers (''he threw himself into the study of Party doctrine with an enthusiasm and energy typical of his eager spirit''). By age 18 he was working on ambitious epic-like novels and was also enrolled in the University of Rostov, where he studied physics and mathematics.
In 1940 Solzhenitsyn married Natalia Reshetovskaya, herself a talented chemistry student. Drafted into the Army the following year, he became an artillery officer and continued his embryonic literary work. His Leninist sympathies (and consequent contempt for Stalinism) ran counter to the prevailing ideology, and in 1945 Solzhenitsyn was arrested and charged with ''forming an organization'' inimical to Soviet interests. The offending action was an idealistic essay Solzhenitsyn had written in collaboration with a friend. The immediate result was an eight-year incarceration during which he was moved from one prison to another, ending up in a forced-labor camp in the Ukraine. The eventual result was a recognition of the Soviet system's repressive inhumanity, which made Solzhenitsyn the system's tireless enemy and released his formidable energies for what would become his life's work.
His release from prison, in 1953, coincided almost exactly with the news of Stalin's death. In that year, Solzhenitsyn underwent successful radiation treatment for cancer (though what may really have saved him, Scammell suggests, were ''his sheer mental toughness and implacable will to live''). Thereafter, he taught physics and astronomy to high school students and simultaneously worked at literary projects already long in progress. His short novel ''A Day in the Life of Ivan Denisovich,'' an exposure of life in the prison camps, was submitted to the influential magazine Novy Mir at a time when ''Khrushchev's new policy of detente and increasing contacts with the West'' had relaxed restrictions against works hitherto deemed unpublishable. Its appearance in 1962 effected Solzhenitsyn's ''transformation from an enemy of the people into a national hero'' - as the book was praised for its (then acceptable) anti-Stalinist sentiment. Still ''A Day'' was denied the Lenin Prize it was expected to win, and there were other strong indications that Khrushchev wanted the limits of his ''liberalization'' policy clearly understood.
Emboldened by his success, Solzhenitsyn began to circulate his works through samizdat (i.e., privately and secretly), and to complete books that made clear his criticism, not only of historical Stalinism, but of the whole continuing thrust of Soviet disregard for individual citizens' rights.
In 1965, the Soviet security police (KGB) forcibly confiscated copies of Solzhenitsyn's major novel, ''The First Circle''; he responded with provocative public statements defying the KGB and with a vitriolic letter to the Soviet Writers' Congress denouncing the government's practice of censorship. After ''The First Circle'' and another long novel, ''Cancer Ward,'' appeared in the West, Solzhenitsyn was formally expelled (in 1969) from the Writers' Union. He was awarded the 1970 Nobel Prize for Literature, but refrained from attending the awards ceremony, fearful that he would be unable to return home. In 1971 came his novel about World War I and the Russian Revolution, ''August 1914''; then, in 1974, the first volume of ''The Gulag Archipelago,'' his analysis of the prison camp system, was published in Paris. Solzhenitsyn was arrested, then deported to Germany - an action that ''allowed the Soviet government to rid itself of its bitterest opponent, while avoiding charges of excessive cruelty and repression.''
After living briefly in Switzerland, Solzhenitsyn settled (in 1976) in Cavendish, Vt., from which vantage point he has occasionally spoken out on American political affairs and positions - always in sternly moralistic and judgmental accents that have offended many admirers and sympathizers, and that contribute to the unfortunately widespread impression that this sufferer and survivor isn't much more than an intemperate crank. Meanwhile, oblivious as always to the world's opinion, Solzhenitsyn works away at the cycle of historical novels which ''August 1914'' initiated, and he continues to amass documentary evidence of the failures of the Soviet ideal.
Scammell ends his book with an account of his 1977 visit to Vermont to interview Solzhenitsyn, and with a picture of his subject in perpetual creative flow, bent on exposing and denouncing the Soviet Union's many iniquities, yet determined he'll eventually return there to ''live peacefully in his own country.''
This exhaustive book offers, in addition to its engrossing chronological narrative, a revealing gloss on Solzhenitsyn's writing. It shows how his finest works are ''firmly rooted in autobiographical reality,'' indicating the appearances of marginal family members and friends, and of the author himself, as important characters in his novels. Yet Scammell shies away from any substantial analysis of his subject's writing (the only detailed readings, perversely enough, are of Solzhenitsyn's surviving ''juvenilia''). And, obviously inhibited by Solzhenitsyn's only partial cooperation with his research efforts, he's been limited to guesswork about some aspects of the life that aren't well documented, and to inference from the novels and the autobiographical volume ''The Oak and the Calf.''
The image of Solzhenitsyn we're thus given powerfully reinforces our impression of him as flawed genius and intemperate saint; a champion of free expression who takes refuge in secretiveness and paranoia, and a major novelist whose rambling, awkwardly constructed books elicit almost as much censure as praise.
Though the novels may always evoke mixed reactions, it seems unlikely that there will ever be any disputing the permanent importance of Solzhenitsyn's masterpeice (thus far), ''The Gulag Archipelago,'' his enormous three-volume ''investigation'' of the Soviet system of organized brutality. This passionate, overwhelming, shrill, and prolix work tells Solzhenitsyn's own story, quotes the testimony of hundreds of fellow survivors, chronicles the history of various secret police organizations, describes how arrests and interrogations were carried out, and implicates and harangues the reader. It challenges the post-Stalinist assertion that such abuses were an aberration peculiar to Stalinism and the Western nations' criticisms of the passivity of the imprisoned. There was heroic resistance, Solzhenitsyn announces and insists, and he catalogs illustrations of hunger strikes, escape attempts, and organized mutinies. It's a work whose importance cannot be overstated.
As successful as ''Gulag'' has been (in Scammell's words) ''in imprinting the Soviet tragedy on the world's consciousness,'' it's as if Solzhenitsyn's very zeal has eroded his reputation among Western - particularly American - liberals. He has made known his ''strictly utilitarian'' view of art and literature, arguing that ''the foundation of literature lies in the deep experiencing of social process''; he's a constant reminder that we who have not suffered as he has suffered are incapable of understanding the world as he understands it.
In 1974, Solzhenitsyn's ''Letter to the Leaders'' challenged the country that had expelled him to undertake ''a programme of radical reform and renewal'' based on an acceptance of the inherent spirituality of the Russian people, and, almost incidentally, dismissed the Western democracies as unformed and insignificant non-countries. In 1978, receiving an honorary degree from Harvard University, he delivered as a commencement address his manifesto ''A World Split Apart,'' in which he foretold the coming domination of the East, and once again lambasted both Soviet inhumanity and the Western nations' shortsightedness and smugness. Recent interviews and public statements have continued his lamentations over America's ''enfeeblement and decadence.''
Solzhenitsyn's ''fanatical dedication to his writing, his career, . . . and . . . his role as a symbol of opposition and as a man with a mission'' led, earlier in his life, to strained, even shattered, relations with many literary friends and benefactors. More recently, his commitment to that master fictional plan to dramatize the 1917 revolution and its aftermath seems to have walled him up within his own indomitable, impregnable ego: Is he, as he claims, a man who writes, compulsively, ''on behalf of the millions who died in Stalin's prisons''?; or is he a solipsistic monstrosity convinced, against all reason and precedent, that only he dares confront the century with the evidence of its madness and folly, that only he can save us from ourselves?
Neither Michael Scammell's book nor any other perspective on Solzhenitsyn conclusively indicates anything as limiting as a coherent or graspable personality. Part of this protean character is pure Russian peasant: For example , while undergoing chemotherapy for cancer, Solzhenitsyn was also employing a traditional folk remedy, a ''mandrake root infusion,'' and his dislike of officialese acronynic prose has led him to write in ''the language of the people ,'' often to deadly dull effect. Yet Solzhenitsyn is also the fire-breathing mystic who intolerantly excoriates societies that seem to him less ''spiritual'' than his idealized homeland - and, indeed, the intellectual flagellant who opened ''The Gulag Archipelago'' with an impassioned apology for its errors, and for his own failure to ''remember it all.''
Nothing is permitted to compromise Solzhenitsyn's need to speak his message. There even seems to be evidence that he was, quite literally, prepared to risk ''sacrificing'' his children - if publication of his works should endanger their safety.
It's easy to take note of the contradictions and inconsistencies that riddle Solzhenitsyn's abrasive and adamantine persona; perhaps it's even easy to shrug him off as an embittered hysteric who sees bloodshed and barbed wire where others envision accommodation and detente. It's too easy.
There must, we feel, be a middle ground somewhere between Solzhenitsyn's unforgiving urgency and our own hopeful, cautious blueprinting for the future. But he will not relent, would not agree. Just as it haunts the Soviet powers exactly as if they had indeed murdered him, the image of Solzhenitsyn troubles our own peace and complacency.