By Blake Gopnik
Washington Post Staff Writer
Tuesday, April 7, 2009; C01

Who is Marcel Duchamp? He's the man who, in 1912, made the masterpiece of modern painting titled "Nude Descending the Staircase, No. 2." Except when he's the virulently anti-painting guy who, just five years later, took a standard urinal and declared it to be a work of art.

Duchamp is the entirely cerebral genius who just about abandoned art in favor of chess. Except when he's the aging letch who worked in secret on "Etant Donnés," a laboriously crafted peep show that's far too crude for us to present in this paper.

Just when you think you know Marcel Duchamp, he slips away again. And that may be the most important thing about him. At least, that's the strong impression left by "Inventing Marcel Duchamp: The Dynamics of Portraiture," an ambitious show at the National Portrait Gallery. The exhibition adds yet another, little-acknowledged dimension to Duchamp: It argues that the art of portraiture -- in Duchamp's self-portraits and also in images he let others make of him -- was central to his whole career. And it shows that, for Duchamp, portraiture was all about demolishing our stale ideas about an artist -- or a person -- as a single, stable thing. In the 100 portraits in this show, Duchamp can be male one minute, female the next. He can be a European man of letters or an outlaw from the Wild West. He can be a fleshy prizefighter or a champagne glass full of inanimate scraps.

A portrait can't get at the essence of its sitter -- because such essences, Duchamp says, do not exist. That makes this show an ideal fit for a museum devoted to digging deep into the art of portraiture. But it may also make you wonder what to make of the museum's other 20,000 pictures of significant Americans.

Duchamp has earned a place among them as the most influential artist ever to make a home in this country. Though born in France in 1887, he lived in New York from 1915 to 1918 and then again from 1942 until his death in 1968, 13 years after taking U.S. citizenship.

One reason portraits mattered almost from the start of Duchamp's career, according to this show, was that that career, especially as it played out in this country, was built around celebrity.

When his barely figurative "Nude Descending a Staircase" first arrived at the Armory Show in New York in 1913, before Duchamp himself had ever made the trip, it caused such an uproar that it came to stand for the entire, questionable enterprise of modern art. The fame of the work soon rubbed off on the man, and onto pictures of him. Duchamp's art became him, and he let himself become his art. As he once said, "The idea of the great star . . . is based on a made-up history." He was happy to assist in making himself up.

Duchamp's most famous self-portrait photographs -- pasted into some of his own works and also used in 1921 for the cover of a magazine called New York Dada -- depict the infamous painter in drag, done up as a primly fashionable matron named Rose Sélavy. That's a pseudonym Duchamp had already used to sign or even copyright his works; when sounded out in French, the name turns into the stoic "Rose C'est la vie" or "That's Life Rose" -- which Duchamp later changed to the sexier Rrose Sélavy, a pun on the French for "eros is life." The young Catholic man, already well-known in that guise as the painter of a famous picture, was not afraid to try on a new gender, age and religion. ("Sélavy" is also a riff on the common French-Jewish name Halévy; before deciding on his gender switch, Duchamp had thought of simply recasting himself as a Jew.)

As Duchamp said, however, the goal "was not to change my identity, but to have two identities" -- not to definitively switch who he was or how people read him, which is what cross-dressing or conversion usually accomplishes, but to multiply identities so as to undermine them all. "I don't believe in the word 'being,' " Duchamp once said. "The idea is a human invention. . . . It's an essential[ist] concept, which doesn't exist at all, and which I don't believe in."

In 1917, Duchamp had already diluted his "being" by turning himself into identical quintuplets, thanks to a photo taken in a five-way mirror. Once he came up with Rrose, that dilution really took off. By 1923, he'd put his own face, in profile and square on, on a fake "wanted" poster that called for the arrest of a certain George W. Welch, "alias Bull, alias Pickens . . . known also under the name Rrose Sélavy." With Duchamp, the kind of handbill that's usually used to clear up identity, and to point to a single individual, multiplies identities instead.

A year later, Duchamp's artist friend Francis Picabia put Duchamp's "face" on the cover of the magazine 391 -- but the portrait was in fact a picture of the famous boxer Georges Carpentier, who looked a good deal like the artist. It had been Duchampified by sticking on the artist's ever-present pipe and the autograph of Rrose Sélavy.

In 1942, needing to supply an artist photo for an exhibition catalogue, Duchamp chose instead to put his name below Ben Shahn's famous shot of a destitute farm woman, chosen because she happened to share the Frenchman's nose and jaw line.

And two years later still, for the last page of a special Duchamp issue of a magazine called View, the artist for once supplied a real photo of himself -- but one titled "Marcel Duchamp at the Age of Eighty-Five," inscribed with the future date of 1972 and shot to make the 58-year-old look ancient.

Many of these pictures, though they seem clearly about self-portrayal, aren't by Duchamp himself, at least in any standard sense of "by." In fact, one of their main points is to question authorship -- one of the most crucial "identities" attached to any work of art.

In those first Sélavy photos, is their true author the artist who dressed himself in women's clothes, or that other artist -- Duchamp's close friend Man Ray -- who snapped the shutter? And who's the real artist behind that artist-portrait for View -- Shahn, who meant the photo only to depict a migrant woman, or Duchamp, who chose it to stand in for himself? The picture counts as one of Duchamp's trademark "readymades," and as with all such works, you want to ask -- you are supposed to ask -- if the credit belongs to Duchamp, or to the person who first made the object he's turned into art.

In fact, Duchamp's most famous readymade, the urinal he titled "Fountain" and had rejected from a show in 1917, also counts as the first time he concealed himself behind an alternate identity.

First, Duchamp tried on a female role: He started out by claiming that the piece was in fact by a certain "female friend," and we've no way of knowing if that claim, never repeated, is literally true, or if his friend was just another avatar of Rrose. (Some now say the landmark work is really "by" the Baroness Elsa von Freytag-Loringhoven, dada's wildest practitioner. A photo of her so-called "Portrait of Marcel Duchamp" -- a lost sculpture that was the first-ever work of assemblage, and which portrayed its subject as a champagne glass filled with sparkly scraps -- is this show's best image of Duchamp that isn't by the man himself.)

Then Duchamp scrawled the imaginary artist's signature "R. Mutt" onto the urinal, shifting authorship, and his own identity, once again. And all along he broadcast that the urinal itself came from the New York firm of J.L. Mott.

"Fountain" isn't in this show, despite its shape-shifting signature. That's a shame, because it would have meant more than several relatively recent portraits of Duchamp. They're by conceptual artists who try to do homage to the founder of their discipline, but mostly seem derivative of him.

"Fountain" would also have outshone a number of traditional portraits by Duchamp's contemporaries that are simply dull and worshipful, and that completely miss the points Duchamp had scored about identity and portraiture.

One exception is a seemingly straightforward etching that Man Ray did of his trickster friend, with the letters "C-e-l-a" and "v-i-t" inscribed to either side of a tiny rose scratched into its bottom corner. That's usually taken as yet as another play on "Rose Sélavy," this time meaning "cela vit" ("it lives").

But the letters also sit precisely where you'd expect to see the standard inscription "sculpsit" (Latin for "he engraved it") or "delineavit" ("he drew it") under the signature on an Old Master print. This time, however, I believe we're meant to read a Latin word that declares what is almost always true about the sitter in this image: "celavit" -- "he concealed it."

Inventing Marcel Duchamp: The Dynamics of Portraiture runs through Aug. 2 at the Smithsonian's National Portrait Gallery, at Eighth and G streets NW. Call 202-633-8300 or visit http://www.npg.si.edu.