The most interesting and telling discussions about the relevance of art come not from critics, art historians, curators, or the public, but from artists. Visual art is much more than a craft or a discipline. It is a poetic language as rich, complex, and nuanced as any other. Art, to be practiced or to be read, requires fluency. It also inspires passionate discourse. Yet, once someone is fluent in art’s universal language, the art of the entire world is open to discovery. And you can learn a lot about an artist by what art he values. Not all artists, however, are fluent. Some have limited vocabularies. Others do not even recognize that there is in fact a language at all, or stress grammar and punctuation at the expense of rhythm, melody, and metaphor. Yet those who do love and understand art usually recognize it when they see it — no matter what form it takes. That is why it is particularly troublesome that the National Academy, an artist-run institution, chose not to recognize Modern abstraction for the greater part of the last 100 years.

“The Abstract Impulse: Fifty Years of Abstraction at the National Academy, 1956–2006,” curated by Marshall Price, attempts to redress the oversight, which was not fully acknowledged until 1980. In short, the exhibit is too little, too late. This collection of approximately 50 paintings, prints, and sculptures (some of which do not actually qualify as pure abstraction), betrays the academic thinking of the National Academy as a whole.

In an essay in the catalog, Mr. Price writes that “an emerging artist [asked him] if the National Academy was ‘that figurative place.'” Indeed, that is basically what it has been since it first opened in 1825. And yet the fact that it is an institution that favors representational art is not the problem. The issue is not one of representational art versus that of abstraction. The issue is one of quality. When an institution becomes defensive about its position, or attempts to move in fast-forward, as the National Academy has done recently, it risks laying bare its fundamental deficiencies.

As I have said in the past, the National Academy and its museum, which has recently mounted important shows of Jean Hélion, David Smith, and Louis Michel Eilshemius, are a crucial part of the New York art world. But sometimes they just don’t get it.

Lately, the National Academy has attempted to shake off the dusty label of “figurative.” In recent years, it has included installation, video art, and, increasingly, abstraction in its exhibitions. It has also admitted abstract artists as academicians. But, as “The Abstract Impulse” demonstrates, academic thinking, applied to figuration or abstraction, painting or installation, is no less academic.

Divided into three categories: “Gesture,” “Geometry,” and “Introspection,” the exhibit simplifies the language of abstraction — and art — as it widens, rather than unites, the shared integrity between representational and abstract art. The “Introspection” wall label states: “Abstraction, absent of representation, is an inherently mysterious mode of creation. Its explanation may often lie far beyond the physical surface of the painting, print, or sculpture.” I am not exactly sure what this means, but I believe that the implication here is that what each of the representational artists Leonardo, Vermeer, Michelangelo, and Balthus do — different from that of abstractionists such as Mondrian, Kandinsky, and Klee — is not inherently mysterious; and that figurative artists do not rely on introspection. This is a misunderstanding not just of abstraction but of visual art.

Many of the works in the show, such as Robert Goodnough’s “Battle One” (1992), Elmer Bishop’s “#35” (1978), James Kelly’s “Hurly-Burly”(1991),StephenGreene’s “Night” (1982), Paul Russotto’s “The Broken Mirror” (1982), and Marion Roller’s sculpture “Empathy” (c. 1985) are representational works masquerading as abstractions: They are figurative spaces filled with amorphous, three-dimensional objects. Or, as with Robert Mangold’s “Frieze Study I” (1994), Leo Manso’s “Kerouan I” (1977), and Vincent Longo’s “Untitled” (1995), they are merely decorative patterns without spatial tension.

“The Abstract Impulse,” which also includes a neon bas-relief by Stephen Antonakos and a neoncolored Op-art painting by Richard Anuszkiewicz, gives us variety without integrity. This exhibit, without really exploring what makes abstraction a unique language different from representation, submits that anything that is not representational is abstract. That is like saying that anything that is not a novel is poetry — that anything that is not meat must be bread.

Granted, “The Abstract Impulse” includes some luminary talents. Gyorgy Kepes’s oil and sandpainting”NativeFragments” (1972) creates a world that is both watery and earthen. In the picture, an aquarium or window of ebullient liquid greens and blues is buried in the sand like a treasure chest. We are able to move from internal to external, from under to above. Bernard Brussel-Smith’s engraving and softground etching “Cain and Abel” (c. 1957), reminiscent of Schongauer’s engraving “The Tribulations of St. Anthony,” is a masterful dance or struggle between line and shape. Will Barnet’s “Joyous” (2006), a gray field brought to life through its figure-ground interaction with pictographic forms, is strong. And Pat Adams’s sparkling mixed-media painting “Des Clefs” (1990), in which the circle is explored as atmosphere, fluid, and matter, as well as location, energy, and growth, is one of the strongest works in the exhibit.

But the show’s catalog is dedicated to Jules Olitski (1922-2007), who was elected to the National Academy in 1994. Olitski is represented in the exhibit by “Salome Rock” (1990), one of his signature heavily impastoed paintings — a thick and empty mess, over which he has sprayed color. He, along with Pop-artist Jasper Johns and Abstract Expressionists Helen Frankenthaler and Robert Motherwell, represent some of the overrated heavy-hitters who have recently been named academicians. Their inclusion in this show gives me the impression that they are here first and foremost as acknowledged art stars, as ringers; and that the National Academy, willing to bet on textbook stardom rather than on genuine talent, is still unsure about just what an abstract work of art actually is.

Until January 6 (1083 Fifth Ave. at 89th Street, 212-369-4880).