A great writer is like a second government. - ''The First Circle'' It has been 10 years since Alexander Solzhenitsyn emigrated to the West, after public outcry on his behalf from nearly every country in the free world. At the time, the West did not know what to expect from Solzhenitsyn. We knew him as a Nobel Prize-winner, a heriocally outspoken critic of the Kremlin, and as the greatest living Russian writer, author of the ''Gulag'' - a man of incalculable moral purity, monumental enough to speak almost as the soul of his country; the direct heir of Tolstoy and Dostoyevsky.
It was probably the author of ''War and Peace'' that we expected to find stepping off the plane in Frankfurt in 1974. But almost from the moment he landed, Solzhenitsyn thrust himself upon the West more as an Old Testament prophet - a Jeremiah breathing peril, a Moses come down from the mountain - than as a merely grand literary or cultural figure such as we are used to. The fact is, we have had nothing like him in recent years.
Looking back, Solzhenitsyn seemed as unprepared for us as we were for him; certainly he was aghast at what he found. For one who, as he has often said, ''worshiped'' the West for years, the decadence he saw, the lack of spiritual resolve, the (to him) ineffectual and naive attempts at detente with the Soviet leadership meant nothing short of an imminent collapse of Western society.
His frequent jeremiads in articles and speeches became eloquent variations on this theme, culminating in his blistering address at Harvard in 1978 - which seemed to many an almost total incrimination of the West. Harvard was a turning point after which much unqualified support for Solzhenitsyn began to end.
Michael Scammell, who helped found the magazine Index on Censorship, and whose biography of Solzhenitsyn is now the authoritative work, attributes his subject's alienating intensity to the environment (''the difference between water and air'') Russians find in the West. ''In the Soviet Union,'' he notes, ''writers put an enormous amount of effort into achieving the slightest effect. When they come to the West, they look funny, they seem to be gesticulating wildly . . . because the air is thinner here.''
Noted British author Bernard Levin consistently supports Solzhenitsyn's position. ''It is no use trying to fit him into our own safe categories;'' Levin writes, ''he transcends them all.''
Yet even within conservative quarters - where he originally found the warmest welcome - Solzhenitsyn is seen as misunderstanding democratic ways and means. Michael Novak of the American Enterprise Institute observes, ''We are all enormously in Solzhenitsyn's debt . . . but at times his viewpoint seems so transcendent that he overlooks the need for checks and balances in political economy and fails to recognize that a genuinely free political economy will reveal the vulgarity as well as the glories of free men and free women.''
In 1984, critics, the press, and intellectuals are still wary of Solzhenitsyn. He has retreated, ever-implacable, to Vermont - a philosopher-king in exile writing his major work: a series of novels on the Russian Revolution.
The West and Solzhenitsyn have become, then, something like the ends of two highly charged magnets that repel each other. And it is into the ''vacuum'' between them that Scammell's comprehensive, elegant biography is issued.
Previous studies were written while the subject was still in the Soviet Union. While useful, those works contained uncertainties and lacked specific details of his life. Scammell's biography takes up this slack. His book, nine years in the writing, incorporates an unheard-of week of interviews with Solzhenitsyn, intelligently filters in massive amounts of material from his body of work (itself mostly autobiographical), runs just short of a thousand pages, and is a model of biographical integrity.
The man who says his viewpoint was formed around campfires in the freezing Gulag was born one of the ''October children'' - the generation following the revolution in 1917. He was infused with Marxist-Leninist zeal, something Solzhenitsyn lost only in the Gulag. What he gained in prison was an acquaintance with his deeper self, an understanding of pain, a faith in spiritual regeneration, a bare-bones view of good and evil, and that love of peasant fortitude and dignity that so influenced the later Tolstoy.
Solzhenitsyn emerges in the book as a giant - a man of immense resources, indifferent to comfort, able to work well under extreme physical and mental pressure; a man who feels a religious demand to restore historical truth to his people.
At the same time he appears as one who has had to live by cunning, by laws of the jungle, and as one whose overconcern with his own role in history too often drowns out needful magnanimity.
Still, Scammell summed up the theme of this biography when he told the Monitor: ''The core of his (Solzhenitsyn's) greatness is . . . that when the chips were down, he did it. He rose to the occasion far more consistently than any of his peers.