In recent weeks a genuinely exciting development has occurred in American literature: The publication of important new novels--"breakthrough novels," the publishing industry would call them--by two writers whose enormous abilities and potential have been recognized for more than a decade. There can, or should, be no question that these new books establish their authors as "major" writers of their generation.

The writers are Gail Godwin, author of "A Mother and Two Daughters," and Paul Theroux, author of "The Mosquito Coast." At first glance their novels are almost totally dissimilar. "A Mother and Two Daughters" is an expansive book, strongly influenced by the Victorian tradition, about three women trying to find places for themselves in a family and a society both of which have undergone major changes; "The Mosquito Coast" is about a flamboyant American eccentric who moves his wife and three children to the jungles of Honduras, fleeing what he sees as the imminent destruction of American civilization and setting up a new civilization of his own. Yet unalike as these books may seem, upon closer examination they reveal striking similarities, and point to themes that may come to characterize their generation's fiction.

Let me hasten to say that generalizations, about generations or anything else, are at best hazardous and at worst fatuous. The Lost Generation wasn't lost and the Beat Generation wasn't beat; those were handy, glossy labels, of the sort favored by the news magazines, that in point of fact had no real meaning. The generation of Americans to which Gail Godwin and Paul Theroux belong also counts among its members Thomas Pynchon and Anne Tyler; generalize at your own risk, thank you.

Yet it remains that those of us who are now in our early forties have lived in the same world, even if our experiences of it have been entirely different. With the exception of a few of us, we are a generation that has not been to war: Too young for Korea, too old for Vietnam--yet we are the first generation to grow up under the threat of nuclear extinction. Our memories of the unifying national euphoria of World War II are vague, so we are perhaps less reflexively patriotic than Americans only a decade older than we are; yet by the time the younger generation was occupying the campuses and screaming in the streets, we were old enough to doubt the wisdom or maturity of its blind attack on American values. Interestingly enough it is a Canadian novelist, Mordecai Richler, who in his novel, "St. Urbain's Horseman," has perhaps most penetratingly defined us:

" . . . Jake Hersh felt his generation was squeezed between two raging and carnivorous ones. The old establishment and the young hipsters . . . Unwillingly, without justice, they had been cast in Kerensky's role. Neither as obscene as the Czar, nor as bloodthirsty as Lenin. Even as Jews, they did not fit a mythology. Not having gone like sheep to the slaughterhouse, but also too fastidious to punish Arab villages with napalm. What Jake stood for would not fire the countryside: decency, tolerance, honor. With E.M. Forster, he wearily offered two cheers for democracy. After George Orwell, he was for a closer look at anybody's panacea."

As it appears in these new novels by Godwin and Theroux, our generation's ambiguous and ambivalent position produces two clear themes. On the one hand there is a strong urge to locate for ourselves the institutional security that previous generations found in God and country; both novels are centrally preoccupied with family, to which both writers seem to give first loyalty. On the other hand we are sufficiently skeptical of American institutions and values, sufficiently influenced by the various movements and isms that began to take shape in the '60s, so that we look at our country with a clinical and appraising eye; both novels do this, with a beguiling mixture of dismay, vexation, amusement and affection.

In their very different ways, "A Mother and Two Daughters" and "The Mosquito Coast" are old-fashioned family novels. Godwin's is a modern variation upon the Victorian multigenerational saga, with the family--ultimately an "extended" family--serving as metaphor for society. Theroux's is, as the reviewers have pointed out, true to a number of literary traditions; but perhaps the most important of these is the one, dating back at least to Daniel Defoe, that sees the family as both world unto itself and defense against the outer world. What matters most in both books is that the family, as institution, is given more than mere affirmation; it is celebrated and exalted, in a way that only a decade ago would have been sneered at in literary circles as hopelessly unsophisticated and anachronistic. Godwin and Theroux are secure enough in their view of the world to be able to embrace tradition without embarrassment.

Yet they are also acute and unsparing critics of the society in which their families attempt to survive. Godwin reaches beyond the confines of the Strickland family to comment on a broad spectrum of topics, ranging from the operating methods and moral conundrums of business (as seen through the eyes of the pesticide manufacturer, Roger Jernigan) to the politics of making it in small-time local television. Theroux goes even farther, taking on just about every manifestation of American folly and vulgarity as seen through the eyes of Allie Fox, the cranky Yankee who occupies the tumultuous center of the novel.

There's nothing new, of course, about the novel as a vehicle for social criticism. But what is interesting about the stance taken by both Godwin and Theroux is that although it originates in a rather radical view of America--the strong political and social views of both writers are sharply evident in all their previous work--that radicalism is tempered by an awareness of the possibilities the country offers and an admiration for its native ingenuity. This is especially arresting in the case of Theroux, who has lived abroad for two decades, primarily in England, and whose writing has up to now had an "international" character comparable to the work of Graham Greene; it seems to me that for Theroux "The Mosquito Coast" is a symbolic if not actual homecoming, a confrontation with American themes that he has not previously made in such depth--and a more complex, less judgmental consideration of those themes than his previous work might have led one to expect. The conclusion he has chosen to give the novel confirms me in this view.

These are, let it be emphasized, quite tentative musings upon two books that are far too new, far too fresh in my mind, to permit anything more at this point; I should also acknowledge at least the possibility that I have managed to find in them what I want to find in them. Yet the high accomplishments of both novels simply cannot be gainsaid. Both are the work of writers who seem to have acquired a larger understanding of the accommodations that life exacts, who have reached that degree of wisdom and maturity that produces literature of lasting value.

This, I think, is what both of these novels are. The comment that I made in reviewing Godwin's novel--"It is everything that a novel should be: funny, sad, provocative, ironic, compassionate, knowing, true"--applies equally to Theroux's. To come upon two such novels within the space of a few weeks revives my faith in the future of our literature and gives me greater hope that my generation has, indeed, something to say to the world.