The humor, the exactitude, the unembarrassed self-knowledge-everything about that remark reminds me of another self-confessed American aesthete, the poet Wallace Stevens. Artists and writers of this persuasion-Henry James and Marianne Moore belong in the same company-cannot be expected to command the attention of a large public. Their work tends to be a little too special for mainstream taste, and the acclaim they enjoy tends to be posthumous. Yet their achievements are among the finest in American art and literature.

Demuth's place in this constellation of talents would be more widely recognized if we saw his work more often, but exhibitions of his pictures have been a rarity lately-which is why the exhibition that Thomas S. Holman and Virginia Zabriskie have organized at the Zabriskie Gallery is an event to be cherished. Though it's a long way from being the full-scale retrospective that's needed, the show's 31 items-mostly watercolors and drawings dating from 1907 to 1933-are more than sufficient to remind us of Demuth's virtues.

Watercolor was his forte, and intimacy of scale his preferred practice. It might be said of him in this respect that he brought Winslow Homer's outdoor aesthetic indoors, where he could concentrate on his two favorite subjects: bouquets of flowers and groups of figures. Even his beautiful beach scenes, with their scantily clad bathers, are given a party atmosphere. His pictures of actual party scenes are masterpieces of social observation flavored with a sharp edge of wit. One of the best of them in the current show is Barron Wilkins' Little Savoy (1917), in which dancing couples and seated drinkers fill to overflowing a luminous composition measuring eight by 101¼4 inches.

It's one of the characteristics of these watercolor compositions, moreover, that within their confined dimensions, every separate element remains distinct in commanding our attention. This is as true of the flowers in the glorious Zinnia Bouquet (1925), with their delicate, variegated reds, as it is of the individual revelers in Barron Wilkins' Little Savoy . While the physical scale of the pictures remains intimist, the images we carry away in our memory tend to expand, so that it comes as something of a surprise when we return to the pictures and find that they're as small as they are.

No doubt the modest dimensions that Demuth favored in these pictures owed a great deal to the somewhat reclusive life he was obliged to live for health reasons in the later years of his life. Lame since early childhood and never robust, he suffered from diabetes and produced a good deal of work in his studio bedroom in the family home in Lancaster, Penn. That studio bedroom in the Demuth House is now a public art museum devoted not only to Demuth's work, but to other 20th-century American modernists as well.

For newcomers to Demuth, it must also be pointed out that the watercolors and drawings in the current show at Zabriskie represent only a part-albeit a major part-of his oeuvre . There are two other aspects of his production that only a comprehensive retrospective could encompass. One would be his literary illustrations, especially his sexually charged drawings of scenes from Henry James' The Turn of the Screw , which (apart from the genius of the draftsmanship) show us a side of Demuth's sensibility not apparent in his flower pictures or party scenes-his taste for emotional violence.

The other, more amusing aspect of the Demuth oeuvre that's absent here are the symbolic portraits he made of his contemporaries. The one that's best known to New Yorkers is the "portrait" of the poet William Carlos Williams called (after a Williams poem) I Saw the Figure Five in Gold (1928), which is now in the collection of the Metropolitan Museum of Art. Williams is said to have loved it, but Demuth's less obliging symbolic portrait of Gertrude Stein caused the writer great distress and effectively terminated their friendship.

We really do need a big museum retrospective if Demuth's achievement is to be fully understood. Meanwhile, the current Demuth show is not to be missed. It remains on view at the Zabriskie Gallery, 41 East 57th Street, through March 6.

In the paintings and watercolors of John Marin (1870-1953), everything derived from both nature and the man-made environment is transformed into vivid action, commotion and syncopation-a variety of lyric upheaval that is larger than life in its intensity of expression, while remaining firmly tethered to the lineaments of our earthbound experience. "Fast" was the key word used by Paul Rosenfeld to describe Marin in his classic study of the American avant-garde, Port of New York (1924), invoking at least two of this word's several meanings: speed, of course, but also what Rosenfeld characterized as "rooted in good ground."

The excesses of his overripe prose notwithstanding, Rosenfeld's description of Marin's painterly dynamism at the height of his powers has never been bettered. Marin, wrote Rosenfeld, was "restlessly, unconsciously busied transforming the materials amid which he stands, dayshine and moisture and minerals, pigment and water and white sheets of Watman paper, into the fresh, firm, savor some pulp of his art. Each year he gives himself anew in liberal windfalls, strewing on the soil about him his explosions of tart watercolor: slithering suns and racing seas of the coast of Maine; wet, fishy poems of headlands and pine-pinnacles and rain-gusts in which the rocky strength and almost Chinese delicacy of a sensitive and robust nature have been completely, miraculously, released."

With the photographs of Paul Strand (1890-1976), we encounter a very different sensibility. In this pictorial oeuvre , nature is devoid of disturbance, action is suspended in the interests of observation, and the man-made world is likewise made to conform to a certain order and etiquette-at times, indeed, a certain geometry. Even the sea is often becalmed, landscape acquires some of the attributes of still life, and every closely observed subject-whether a horizon-line dividing the sea from the sky or something as delicate as a cobweb in the rain-is rendered with a preternatural clarity and precision, enabling us to savor the clean contours and fine detailing of every object. This is equally true of Strand's iconic portraits, in which concentration and candor are given priority over intimacy and sentiment-a strategy that, in Strand's case, anyway, endows every portrait with the weight of a penetrating character study.

They belonged to different generations. Strand, the younger by 20 years, was closer in his generational affinities to precisionist masters like Morton Schamberg (1881-1918) and Charles Sheeler (1883-1965). When, as a young man, Strand first brought his photographs to Stieglitz for criticism, the master is said to have been so impressed by the abstract patterns to be seen in the pictures, whatever the subject, that he promptly gave the young photographer his first solo exhibition at "291." That element of precisionist abstraction remained a hallmark of Strand's style for many decades.

Marin, for his part, was by temperament a headlong expressionist-exuberant in invention, impatient with finish and indulgent of repetition and improvisation-but an expressionist held in check by a countervailing devotion to Cubist structure, which he blithely bent to his own purposes.

Call this confrontation of opposites a dialogue if you like. John Marin and Paul Strand: Friends in New England is a wonderful show-a show, really, of three major American artists, if you add the genius of Stieglitz's aesthetic perspicacity to the roster of talents on display. It remains on view at the Richard York Gallery, 21 East 65th Street, through Jan. 17, 2004.