When the N.Y. School was tops

No matter how one may feel about what they produced, no knowledgeable art lover can doubt that when the history of post-World War II art is finally written, the dominant position will almost certainly be occupied by the artists known collectively as the New York School.

They will occupy it because of their widespread creative and stylistic influence, numerical superiority, and commercial impact, and because they were modernism's major post-war champions. But most of all because they were, with a few excellent but relatively isolated exceptions, the very best artists around at that time, although the school is no longer in the ascendency.

It consisted of a series of movements, beginning with abstract expressionism in the very late 1940s (when the center of the art world began to shift from Paris to New York), and followed, in fairly rapid succession, by color-field painting, hard-edge painting, pop art, and minimalism.

Several major American artists whose styles did not totally conform to any of these movements' orthodox positions were also loosely included as ''members.'' Thus any exhibition of the period that doesn't include examples of the work of Albers, Calder, Cornell, Gorky, Hofmann, Reinhardt, or Smith (to mention only some of the best-known) cannot be said truly to reflect the New York School.

Although it didn't set out to mount a definitive exhibition of this school, the Guggenheim Museum here has come up with a fairly representative sampling of works by its major figures in a current show, ''The New York School: Four Decades.'' Arranged in roughly chronological order, and drawn from the museum's own collection (with the addition of a few major loans from private collectors), this exhibition is both an artistic and an educational event.

Educational because it is a pleasant, easy, and utterly painless way for those not yet familiar with these artists and their work to get to know something about them - and to do so within a setting that permits the viewer to trace the evolution of this school as he wends his way down the museum's curving ramp, studying the pictures on its walls. The design of the Guggenheim's interior isn't always conducive to the viewing of art, but it is perfect in a show such as this, where one wants to follow the progression of styles through time.

Although no catalog was issued with this show, there is an illustrated brochure. It was written by Lisa Dennison, is of necessity brief, and manages to give as accurate an accounting of the New York School as one would want short of a learned dissertation.

As to the works on view, almost all are excellent examples of the artists, movements, and periods they represent. Some artists are shown at their very best - Roy Lichtenstein's huge ''Preparedness,'' Richard Diebenkorn's ''Ocean Park No. 96,'' Jackson Pollock's ''Ocean Greyness,'' and Richard Lindner's ''The Secret.'' Others - especially Franz Kline, Philip Guston, Robert Motherwell, and Jim Dine - don't come off so well.

All in all, however, it's an excellent exhibition of important contemporary art, and will remain on view at the Guggenheim Museum through Aug. 29.