In a brilliant coup of acquisition, the Portland Art Museum has purchased the entire art collection of the critic Clement Greenberg, making it in one fell swoop the best place to see modernist painting.

Beautifully installed by Bruce Guenther, the curator of modern and contemporary art, the inaugural exhibition makes it clear that Greenberg practiced, as a collector, what he preached as a theorist: the power of the medium as such.

For Greenberg, the best works establish their material presence independently of any subject matter, making esthetically self-evident the positivist ideology of modernity. Greenberg was obsessed with surface, and surface -- sometimes smooth and thin, sometimes lush and volumetric, and always exquisitely nuanced, sensuously alive and radiant with color -- is conspicuously evident in the 19 paintings by Kenneth Noland, 19 paintings by Jules Olitski and six paintings by Larry Poons that form the backbone and bulk of the collection. There are also eight exemplary sculptures by Anthony Caro, including, unexpectedly, a brilliantly expressionistic portrait bust of Greenberg (1990), looking somewhat introspective and depressed.

This last piece signals the fact that Greenberg, despite his proclivity for abstract art, collected figurative and landscape imagery as well, suggesting that he appreciated abstract form wherever he found it, and he often found it in the female body, as drawings of Caro and Olitski, an etching by Richard Diebenkorn, and paintings by Darryl Hughto and Horacio Torres indicate. Anecdotal imagery, then, is not entirely ruled out, so long as it shows a formal intelligence, which I assume is why Buffie Johnson's Chardinesque Fish and Shrimps (1945) is in the collection.

The collection also includes abstract landscapes by Helen Frankenthaler and Friedel Dzubas, and realistic ones by Dorothy Knowles and Ernest Lindner, Canadian artists who memorialize Emma Lake, where Greenberg spent time, spreading his ideas, supporting protégés, and accumulating power and influence.

Greenberg was the connoisseur of a particular kind of art, and his collection is designed to show that it is the only kind of art that matters -- the grand American climax of 20th-century abstraction. This is of course debatable, but it is clear, from the high caliber of the works -- their precious individuality -- that Greenberg's collection demonstrates his power of discernment.

His taste was all but infallible: the collection has some of the best paintings by Walter Darby Bannard and Dan Christensen, as well as choice works by Joseph Drapell, Dzubas, Adolph Gottlieb, Hans Hofmann, Jackson Pollock, Susan Roth and Ludwig Sander, among others. Its lasting value has to do with its usefulness as a highly focused survey of the history of painterly and post-painterly abstraction, to use Greenberg's term.

Greenberg bashing seems to have become an industry in itself, but his collection makes clear that in attacking his formalist esthetics -- backed up by a brilliant historical and philosophical argument, summarized in Karen Wilkin's essay in the handsome, comprehensive catalogue -- one is attacking the very idea of fine art.

Of course, there are those who think ideology counts for more than refinement in art, and outspoken concept more than subtle craft, but the works in Greenberg's collection make it transparently clear that in taking an abstract turn fine art has renewed itself, and has a long complex way to go, suggesting that it is unlikely to ever lose faith in itself.