Literary matters took me to New York last week -- the first presentation of the newly, and grandly, reconstituted National Book Awards -- but artistic ones kept me there: "American Paradise: The World of the Hudson River School," the exhibition being presented at the Metropolitan Museum through the end of the year. Though the artistic merits of the nearly 90 paintings on display can be disputed, their deeper cultural meaning cannot: The work of the Hudson River painters is a powerful evocation of a lost America, and an equally powerful expression of the dream of America that still lives in our hearts.

It was a quarter century ago that I first encountered the Hudson River School, a moment that still reverberates in my memory. Working in New York at the time, I frequently spent my days off at the Metropolitan, which in those less cynical days was still an oasis: uncrowded except on weekends, unspoiled by the taint of gift-shop commerce, still of a sufficiently human scale so as to be both accessible and manageable for the casual visitor. In the early 1960s a visit to the Metropolitan was an escape from the city, a retreat into a quieter and better world, and I availed myself of it as often as possible.

One day while on such a walkabout I wandered into the American Wing, which then was a relatively unprepossessing section consisting of a number of restored rooms from early American houses and public buildings, a few cases of old silver and glassware, and a couple of galleries of paintings. In one of these galleries -- on opposing walls, if memory serves me well -- hung two paintings that, upon first and every subsequent encounter, took my breath away.

The first was Thomas Cole's "View from Mount Holyoke, Northampton, Massachusetts, after a Thunderstorm," familiarly known as "The Oxbow," painted in 1836; the second was George Inness' "Peace and Plenty," painted three decades later. There were significant differences between the paintings, but what drew me to them was their similarity: their depiction of the American landscape before its purity had been compromised and despoiled beyond hope of recovery, and their clear, unsentimental understanding of man's proper relationship to that landscape.

Multiply those two paintings by more than 40 and you have "American Paradise," which draws not merely upon the Metropolitan's seminal Hudson River collection but on museums around the country. Devotees of the school will have their quibbles and grievances -- there are a couple of John F. Kensetts at the Baltimore Museum of Art that I'd like to see included, and the absence of "Peace and Plenty" is certainly a puzzler -- but overall this is probably the most comprehensive Hudson River show ever mounted; for students of American life and culture it means a mandatory trip to the Metropolitan, even at the price of submitting to the various indignities and inconveniences that museum now routinely imposes upon its clientele.

The exhibition begins as it should with Thomas Cole and concludes with such less known members of the school as Francis A. Silva and Worthington Whittredge. But then the truth is that none of the members of the Hudson River School is especially well known, at least by contrast with Winslow Homer, Thomas Eakins, George Catlin and other painters who came to prominence a bit later in the 19th century. This may seem something of an oddity, inasmuch as the Hudson River painters were genuine pioneers in the development of a native American art, but it reflects the critical disdain in which the school was held for nearly a century and from which it has only recently been rescued.

That disdain had something to do with rivalries between artistic factions and something to do with a widespread opinion that the Hudson River painters had an excessive appetite for the histrionic and melodramatic. The first question is irrelevant, but the second cannot be idly dismissed; some of the Hudson River painters -- notably Albert Bierstadt and Frederick Church -- were infatuated with sweeping vistas, ominous, looming clouds and exaggerated colors. Bierstadt's "A Storm in the Rocky Mountains -- Mount Rosalie" and Church's "Cotopaxi" are nothing if not excessive.

But after looking at "Cotopaxi" you should then walk across the room and examine Church's "Niagara." It is dramatic, heaven knows, but what it speaks of is not excessive or overwrought emotion but the artist's heartfelt wonder and awe at encountering a natural phenomenon so marvelous as to defy the imagination; to look at Church's "Niagara" is to see the falls as the first settlers saw them, and to be stunned, as surely they were, by the immense power and beauty of the American landscape. It is the same wonder that we sense in Cole's portraits of the Catskills and Adirondacks, in Kensett's Rhode Island seascapes, in Inness' "Delaware Water Gap," in Jasper Cropsey's "Starrucca Viaduct, Pennsylvania": wonder that such beauty should exist, and that the artist should be permitted to live amid it.

Cropsey's view of the Starrucca Viaduct is a quintessential work of the Hudson River School, not merely because of its panoramic majesty but because it subordinates the works of man, as well as man himself, to nature. A train rolls across the viaduct but it is a toy train, meticulous and unreal, and the viaduct itself is absorbed into nature's plan rather than in conflict with it. Similarly, in Samuel Colman's "Storm King on the Hudson," the eclectic group of boats in the foreground is whimsical and unreal by contrast to the great mountain in the background and the dark storm forming at its crown.

Not merely did the Hudson River painters believe that man, while at one with nature, was wholly insignificant beside it; they also believed that nature would remain forever dominant -- that the landscape would abide. Thus here is Thomas Cole, his great "Oxbow" having been completed, reflecting upon its larger meaning: "Seated on a pleasant knoll, look down into the bosom of that secluded valley ... You see no ruined tower to tell of outrage -- no gorgeous temple to speak of ostentation; but freedom's offspring -- peace, security and happiness dwell there, the spirits of the scene ... And in looking over the yet uncultivated scene, the mind's eye may see far into futurity -- mighty deeds shall be done in the now pathless wilderness; and poets yet unborn shall sanctify the soil."

How little they knew; how vast was their innocence. Only once in all these Edenic paintings, in this exhibit so aptly called "American Paradise," is the true future to be seen, and even then the painter does not fully grasp what he has depicted. It is a painting by Asher B. Durand. In a valley by the water is a small city, whereto wagons are delivering their carts laden with goods and wherein manufacturing plants, at the edge of the water, emit their thin curls of smoke into the still-virgin air. To the left, on a mountain rock beside a tall, commanding tree, stands a small band of Indians, surveying the view below not with hostility or fear but, as the exhibit's superb catalogue notes, "with astonishment and approbation, making the point that they and the wilderness also have a place in this vision of what could be." Durand, in all naivete' and faith, called the painting "Progress.