The Morton G. Neumann Family Collection -- At the National Gallery East through December 31.

When businessman Morton Neumann began collecting modern art he went at it with passion and zeal: "I collect," he says, "out of psychological need. I realize some collectors buy with the expectation that their works may appreciate, but I never even considered that."

It started with a few Picassos purchased in Paris in 1948; since then, the collection has grown in size and scope to include major works from nearly every category of 20th-century art. The paintings and sculptures and drawings are usually housed in Neumann's Chicago home, where he and his friends can enjoy them, but through December nearly 140 samples from "The Morton G. Neumann Family Collection" can be seen at the National Gallery's East Wing.

The exhibit, a vast and glittering showcase, includes a dozen works by Man Ray, a baker's dozen by Pablo Picasso and still more than that by Paul Klee. There are six-teen pieces by Joan Miro, a pair of super-real sculptures by Duane Hanson, drawings and sculptures by Alberto Giacometti and a mobile by Alexander Calder.

Some truly fine examples of photo-realism include paintings by Richard Estes, Audrey Flack, Ben Schonzeit and Robert Cottingham. American abstract painting is represented by Franz Kline, Morris Louis, Mark Rothko, Frank Stella and Kenneth Noland. There's an inscrutable Warhol composition, a funny sculpture by George Segal and a pop painting by Roy Lichtenstein.

Among the most important works -- there really are no minor pieces in this show -- is Picasso's 1909 cubist "Nude," the earliest piece on display. It alone is worth a trip downtown. (Other exciting cubist pieces include Juan Gris's "Banjo and Glasses" and Fernand Leger's "Woman Sewing.")

The show's most curious creation is Man Ray's "Indestructible Object" (1958), a dadaist construction made from a metronome, a photograph and a paperclip.

National Gallery staffers will conduct free tours of the collection beginning next Tuesday. Call 737-4215 for details.