By itself, sincerity is insufficient to make a great work of art. Still, the Abstract Expressionists got plenty of mileage out of it, with soul-baring, chest-thumping canvases that rank among the greatest achievements of American art. But like everyone else, the members of the New York School came in all shapes and sizes, including the self-effacing and well-mannered James Brooks (1906–92). At Greenberg Van Doren, the current installation of 12 paintings by Brooks argues for the more self-possessed and reflective side of a movement known for its carousing.

If Brooks remains one of the least known of the original Abstract Expressionists, it’s due in part to his reticent personality. Yet he was among the very first to employ a staining technique and, like his friend Jackson Pollock, he worked with a drip technique on a canvas laid out on the floor. Spanning nearly three decades, the paintings in “Black and White + Color” delve mostly in blacks, whites, and grays, with the addition of single color in most canvases. One imagines that the theme, which includes infinite possibilities while avoiding egotistical extremes, would have met with Brooks’s approval.

The artist began incorporating intense colors into his paintings during the 1950s. The more subdued canvases selected for this installation have a relatively austere elegance. Typical of the artist’s work, their surfaces acquire depth in multiple, fine layers of paint, testimony to much reworking of compositions. The textures of the earlier oil paintings at Greenberg Van Doren are especially evocative, with feathered edges adding to their atmospheric depth. In “Abacus” (1954), a piece consisting of a vertical stack of three long canvases, black and rust-red forms loop and play on an off-white ground in the lower two sections before releasing circles of color into the uppermost. The mischievous rhythms seem undeterred by the regulating divisions between the canvases. The sequence of rounding darks traversing the width of “Z” (1954) compares intriguingly with Motherwell’s paintings from his “Elegy to the Spanish Republic” series. Brooks’s smaller work is far more intimate in scale, but there are other differences, too: Where Motherwell’s demonstrative style forces shapes into statements, Brooks seems to watch his lyrical forms grow according to their own mysterious ends.

Brooks began using acrylic paint early on, in the 1960s, and the new medium led to cleaner contours and larger, more clearly defined areas of color. If the scumbled, atmospheric marks of his earlier work imparted an effect of meditative incident, his new work had to rely more on the eloquence of his designs. The later works are less luxuriantly textural, less inviting to be touched. But they have a muscular lyricism, apparent especially in a canvas such as “Fonteel” (1974), in which broad areas of white wheel among black shapes, lifting toward a ragged core that emits neat trickles of pale paint. In “Hoon” (1980), whites on either side — a wide plane at right, a spindly line at left — rise in concert and join high above a confetti-like nest of gray and white squiggles. Both of these canvases, like his earlier oil paintings, have a reflective spontaneity; they seem self-animated, as if the artist were impassively watching himself paint from another dimension.

By New York School standards of gestural abstraction, Brooks’s later paintings sometimes exhibit a degree of control, and even calculation, in the pitting of drip against swath, and glazed depth against opacity. All of them tend to resolve themselves as moods, rather than advancing themselves as statements. These qualities distance the work somewhat from the Abstract Expressionist aesthetic, which demands material evidence of passion in the rawness of technique.

But “Ab-Ex” has no lock on sincerity, and there are many other measures of ardor. Back in 1952, Brooks laid out his goals in a catalog, stating that “manipulation of meaning to assure an audience would destroy the reality of the work and debase the concept of communication.” The artist was always his own painter, it seems, and a half century later, his version of passion feels just as original.

Until March 22 (730 Fifth Ave. at 57th Street, 212-445-0444).