Back in the 1970s, Conceptual Art was notorious for its high seriousness. Conceptualism called for a temperament that was ascetic, politically portentous and relentlessly critical of received notions of art. "Art as Idea as Idea," as Joseph Kosuth dubbed it, was all about ideology, epistemology and linguistics.

And then there was Don Celender, the creator of Artball Trading Cards (1971), which presented artists like Pablo Picasso, Jasper Johns and Larry Rivers as baseball players, each assigned a position and identified on the back by a "hit" artwork.

Celender brought a little comedy into Conceptual Art.

A professor for 40 years at Macalester College in St. Paul, Minn., Celender died at age 73 on Mar. 1, 2005. He had his first solo show at O.K. Harris Gallery in SoHo in 1970, and his work is now the subject of a retrospective exhibition there. Although it includes toylike works such as the trading cards, art-shaped animal crackers and snowglobes with little art replicas inside them, the show focuses on Celender’s "conceptual documentation" projects – a series of questionnaires about art or esthetics, sent out to people in all walks of life, which he would post in the gallery as artworks.

New York Times critic Roberta Smith was on the money when she referred to Celender as the "pollster laureate of conceptual art." He began his work with projects like the Corporate Art Movement, Mass Media Art Movement and Organizational Art Movement (1969-70), writing to large institutions like General Motors, the Guggenheim and Playboy and proposing that they assist him in a series of humorously impractical art projects, then documenting their responses.

He proposed to G.M. that the auto giant produce a line of cars using the dimensions of Ralph Nader’s body. He suggested that oil companies elevate their petroleum pipelines and make them transparent, so that Americans could observe the sculptural beauty of their oil. In another project, he wrote to trucking companies, asking them to transport an eight-ton cake replica of Myron’s Discobolos. Seeing all of Celender’s letters together, they have an engaging, child-like quality in the directness of their address and their simple, repeating form.

This gesture is winning enough that it is easy to miss the subtle complexity that Celender brings to it. The humor of the "crazy letter" joke depends on the viewer’s belief that someone else is a sucker; the person responding isn’t in on the joke, but we are, so we laugh when we see it taken seriously. But Celender’s temperament is such that his work never rests on his superiority to his participants. Indeed, while some of his respondents seem befuddled, upon inspection what is most striking is that they are consistently wise to his game. The Container Corporation of America, for instance, answers Celender’s proposal to "displace all the space" in U.S. art institutions with refrigerator-sized boxes with a simple, sardonic, "It’s great fun to be in the Art World!"

When Celender suggested to the Georgia-Pacific Corporation that they build an enormous box painted with clouds and trees around the city of New York, Robert D. Lee replied with a surprisingly vigorous social critique of Celender’s work. "In these times of social and economic need – when so many people in our world are dying of hunger and disease – when adequate housing, education and medical care is denied to millions – when social and environmental problems create critical issues of pure survival," he wrote, "your proposal can only be viewed as one without merit."

Perhaps most bracing of all is the response of AFL-CIO director William L. Kircher, answering Celender’s repeated requests that he consider a project to coat the Capitol Dome with melted union dues. Kircher replies that he had given the artist credit for not expecting a response, adding, "Your insistence, however, indicates that you could never understand or appreciate the fact that someone might honestly take the American labor movement and its purpose in our social order quite seriously or that a person in my position might consider his role and responsibility one that is beyond the kind of flippant arrogance and disdain characterized by your letter."

Reading these responses, one might at first have the feeling that it is the artist, and by extension the gallery-going viewer, who has been made the sucker, having their desire for an easy laugh turned right back at them. But what they show is that the heart of Celender’s enterprise is not pranks; because his works are always about dialogue, they never take for granted the high ground. These comments, however self-righteous, throw into relief the embattled position that art often occupies in contemporary culture. His unrealizable art movements are not devices for taunting the uninitiated; they are a way to show two ideas of art – art as the playful power of the imagination, and art as the servant of social needs – in stark contradiction, without siding with one over the other.

The center of Celender’s work shifted over time, but it held firm to his inscrutable theme of embracing the different, conflicted meanings that art has for people. Repeatedly, Celender went outside the professional art world to survey different groups (soap opera actors, career military officers, celebrity chefs, blue-collar workers, etc.) for their opinions on various artistic issues. Though these art-as-documentation works lack some of the intellectual drama of the earlier projects, they have a knack for isolating points where the serious and the absurd become indiscernible. In his Business/Art Survey of 1981, for instance, Celender sought out the owners of various businesses such as Artistic Homes, Inc., Artistic Silk Floral Designs and Artistic Dental Ceramics to quiz them about the meaning of the word "artistic" in their company names. What comes through is how important the idea of art is to them, while at the same time how distant it is from anything that would legitimate something in a gallery.

When Celender turned his questionnaires towards savvier art-world participants, the difficult relationship between high and low ideas of art remains the subtle theme. Surveying art critics, he asks, "What qualities from three renowned artists, past or present, would you combine to formulate the ideal artist?" The question is willfully naïve, and the interest of asking it to art critics is, of course, that it belongs to a popular, man-on-the-street conception of art that critics can’t take seriously. Thus, Donald Kuspit and Jerry Saltz both reply with off-the-cuff quips ("blood, sweat, and tears," and "The family wealth of Manet/The sexual stamina of Picasso/The long life of Michelangelo," respectively), whereas Peter Schjeldahl responds with a hand-written rebuttal of the terms of the question.

Asked in one of Celender’s surveys what painter he would like to have paint his portrait, Sol LeWitt responds, tersely, "I would not like my portrait done by anyone, past or present." High conceptual art pursued an aggressive critique of the conventional notion of the art object; Celender, on the other hand, spent most of his life teaching art history at a small, progressive college, where among his favorite classes were tribal art and public sculpture. His first impulse was to expand his audience’s tastes, not to limit them. This is the consistent leitmotif of his oeuvre, in both form and content.

It is Celender’s great merit to have absorbed the essential themes of Conceptualism – the priority of discourse over objects, the importance of context and class – while having at the same time subtly side-stepped its limitations. Celender held to the non-elitist insight that conceptualism was a new potential that had opened up alongside more conventional ideas about art, something that was necessarily in dialogue with them rather than an alternative to them. His modesty is also his strength. His legacy is to have left the world just as rich, while at the same time adding something new that, imperceptibly, changes the way we think about it all.

BEN DAVIS is associate editor of Artnet Magazine.