IF ONE WERE to put letters into categories these would clearly be graded as belonging to some secondary category in which the correspondents discuss ideas, subjects, projects, things they agree or disagree about, but reveal very little that is to do with their personal lives, their relationships, their feelings. They do not fall into what I would call the first category of letters written out of the correspondent's whole personality, like those of Keats, Van Gogh, D. H. Lawrence or Virginia Woolf. There is in fact something rather old-fashioned about them, like a correspondence between two greatly learned, rather peppery bishops of some secular church.

The church, of course, is literature. The conviction that literature is the completely disinterested, sacrosanct activity of dedicated artists is what brings these two minds of great intellectual power and wide range together. It sets them apart from nearly all their contemporaries. This ennobles their correspondence even when sometimes it seems too much engrossed in dealings with publishers and patrons (today, colleges and universities). Without such devotion, the joke of novelist Vladimir Nobokov's contempt for Dostoevsky, Jane Austen, Henry James, William Faulkner, T. S. Eliot and others would wear very thin, especially since his is a mind completely closed. All arguments used by critic Edmund Wilson defending these writers break like lances hurled against a marable wall.

The writers about whose greatness the two agree are Tolstoy, James Joyce and Dickens (we learn that Nabokov's father knew every word of Dickens and had read Great Expectations to Vladimir aloud, in English, when he was a boy).

Wilson comes out of this correspondence extremely well. Having received Nobokov's introduction to him from the novelist's cousin Nicholas in December 1940, Wilson (who was then literary editor of The New Republic ) gives him reviewing, publishers his translation of a verse play by Pushkin - Mozart and Salieri - and sends him prompt checks. He also sends him a copy of his book To the Finland Station and receives a lengthy letter from Nabokov praising much in it but disagreeing with Wilson's favorable account of Lenin which, he indicates, savors too much of official Communist biographies.

Wilson appears in the role of pupil to Nabokov who - largely through Wilson's efforts - becomes a teacher of Russian literature at various American colleges. At first, the critic is not altogether willing to be corrected by Nabokov in his view of recent Russian history. As Simon Karlinsky, in his very opinionated introduction to this volume writes, discussing Wilson's Travels in Two Democracies (1936), "Wilson's account of his Soviet impressions . . . is an affecting mixture of his own naive expectations." Nabokov did much to dispel these illusions. He also corrected Wilson's Russian and explained to him the nature of Russian versification, brusquely informing Wilson that his ideas about it are "as wrong as can be." Wilson does not accept this in very good part, and late in the correspondence sends Nabokov a letter at least as long as the one from the Russian to him, informing Nabokov that he understands nothing of English versification.

In these altercations one has the impression of two strongly masculine minds - stags with antlers intertwined - with no willingness whatever to give way on Nabokov's side, and very little on Wilson's: though the latter nevertheless remains benevolent towards Nabokov, never losing the sense that he is communicating with a genius whom, however exasperating he may be, he continues to admire.

Light relief is provided by the much self-documented spectacle of Nabokov chasing rare butterflies in various parts of the United States, examining them under a microscope, and classifying their genitalia.

This correspondence, whether or not it was intended for publication, is for the most part a studied, deliberate affair, a most conscious attempt by two very conscious artists and critics to continue almost from the time when they first met until the end of their lives, s serious dialogue about the things and values for which they most cared. It is in a grand tradition of such correspondences and it will be for the good of literature if there are men communicating on a similar level at this moment. In 1971, Vladimir Nabokov wrote to Wilson a moving acknowledgement which brings credit to them both:

"Dear Bunny," he writes, "a few days ago I had the occasion to reread the whole batch of our correspondence. It was such a pleasure to feel again the warmth of your many kindnesses, the various thrills of our friendship, that constant excitement of art and intellectual discovery . . . . Please believe that I have long ceased to bear you a grudge for your imcomprehensible incomprehension of Pushkins's and Nabokov's Onegin .

Thus under their writer's relationship they buried theiir much publicized quarrel about Nabokov's translation of Eugene Onegin . CAPTION: Illustration, of Vladimir Nabokov (left) and Edmund Wilson by Richard Willson for the Washington Post