"When I state that I am an anarchist, I must also state that I am not an anarchist, to be in keeping with the (. . . ) idea of anarchism. Long live anarchism." While such words could resound on a placard at Zuccotti Park in lower Manhattan, where the Occupy Wall Street sit-in enters its second month, they were in fact written by Christopher D'Arcangelo (1955–1979), a little-known Conceptualist who is presently the focus of two exhibitions in New York.

"Anarchism Without Adjectives: On the Work of Christopher D'Arcangelo, 1975–1979" at Artists Space in SoHo through Oct. 16, and "Christopher D'Arcangelo Homage," at the West Village gallery Algus Greenspon, through Oct. 29, offer unconventional takes on an artist whose entire ephemeral oeuvre, recorded in a scattering of documents, spans just five years. The show at Artists Space originated at CAC Brétigny, and it will get a third iteration at the Centro Cultural Montehermoso Kulturunea, Vitoria-Gasteiz, Spain, later this fall.

The ellipses in D'Arcangelo's statement of anarchy ("in keeping with the [. . . ] idea of anarchy") obliquely refer to the phrase "anarchism without adjectives," a late-19th-century formulation meant to emphasize the limitless and unrecoverable  spirit of the anarchist impulse. Those Occupy Wall Street protesters have thus far refused to formulate concrete demands, which has frustrated some observers—but perhaps they have opened the kind of space for liberating action that D'Arcangelo pursued so inventively. D'Arcangelo planted the seeds of institutional critique, but because he died so young—a suicide—his practice never coalesced into dogma.

D'Arcangelo won a degree of notoriety in the '70s for a series of breathtakingly simple yet radical actions that briefly disrupted the operations of major art institutions. At the Whitney Museum of American Art in 1975, for example, he chained himself to the front door bare-chested, on a 30-degree day, with his anarchist's anthem written on his naked back. At the Louvre in 1978 he removed a 1745 painting by Gainsborough from its position hanging on the wall and placed it on the floor, leaning it against the wall. He then attached his text, typed on a piece of paper, to the wall where the painting had been. Reactions by officials to his various interventions ranged from baffled consternation to, at the Norton Simon in Pasadena, an arrest.

Back in New York, D'Arcangelo supported himself in part by renovating artists' lofts with artist Peter Nadin. In a stroke at once Duchampian and Marxian, D'Arcangelo reconceived their banal constructions as works of art, with the contracts as documentation.

How does one present such an emphatically nonmaterial oeuvre? At Artists Space there are two long tables bearing monitors that play videotaped interviews with friends and associates of D'Arcangelo—Lawrence Weiner, Nadin, Daniel Buren, Stephen Antonakos and his wife Naomi Spector—and with critic Benjamin Buchloh. Conducted by curators Dean Inkster and Sébastien Pluot, the interviews present fascinating anecdotes as well as some profound reflections on D'Arcangelo's impact and legacy.

Even more organic, and vital, is the treatment at Algus Greenspon. In 2009, Cathy Weiner, D'Arcangelo's girlfriend at the time of his death, along with the D'Arcangelo Family Partnership (which also administers the estate of Christopher's father, the painter Allan D'Arcangelo, 1930–1998), deposited much of the documentation of his artwork at New York University's Fales Library & Special Collections. In the year following the donation, visitors to the archive were asked to contribute responses to the work.

On view are responses by a half-dozen artists, ranging from a set of handcuffs with chains lying on the floor (Dean MacGregor) to a group of documents posted on the wall related to the removed Gainsborough (floorplan, catalogue photocopy, slide, etc.) by Mario Garcia Torres. Screening on a monitor are never-before-exhibited Super-8 films of three of D'Arcangelo's actions at New York museums, shot by Wiener and transferred to video. The Fales documents are available for perusal as photocopies in a binder. And the exhibition should be seen repeatedly over time; visitors are encouraged again to respond, submitting proposals for new work that will augment the show during its three-week course.

Above: Still from video interview with Daniel Buren about the work of Christopher D'Arcangelo, conducted by Dean Inkster and Sébastien Pluot, 2010. Courtesy Artists Space.