The widening of artistic possibilities in the last century has had positive results for the future of art and particularly for an art that engages with issues of sustainability. Besides the production of objects, two new elements have been added to artistic practice: participation and action. But these new possibilities have also created problems of interpretation that must be addressed before we can discuss further art's contribution to a sustainable culture.

Earth artists and environmental artists created projects that drew the spectator in as a participant. The experience of environmental art was immediate and more visceral than viewing a picture on a gallery wall. Environmental art expanded the sites of artistic display beyond the gallery or museum, and even the urban spaces of public sculpture. In Beuys's 7000 Oaks, for instance, people were also invited to participate in planting the trees, not only to walk among them.

Beuys's project, like a number of others, spills over into the realm of action and raises questions about how to determine its aesthetic value. Reforesting Kassel was an ecological gesture to redress the balance of nature in the urban landscape. Though initiated by an artist, it transcended art discourse and became social action. So did a series of similar projects by artists in the United States and Europe. Consider Harriet Feigenbaum's land reclamation work, Erosion and Sedimentation Control Plan for Red Ash and Coal Silt Area-Willow Rings (1985). On a site damaged by strip mining, the artist planted two concentric circles of willow trees around a pond that was formed from coal-dust run-off. The site became a public park that also preserved the memory of the land's prior use. Similarly, Bonnie Sherk founded The Farm in 1974, bringing together an interdisciplinary team to create a sustainable ecosystem and educational park on a piece of unused land near a San Francisco highway interchange. Finally, Mel Chin's Revival Field (1990-93) at Pig's Eye Landfill in St. Paul, Minnesota, became a biological experiment in which the artist explored the use of plants to remediate the soil in a landfill that had been contaminated by heavy metals.

Formal qualities are easy to identify in the projects by Beuys, Sherk, or Feigenbaum, where we are looking at configurations of materials, whether artificial or natural, in patterns. But what about Chin's research on plants to remediate contaminated soil? Where is the aesthetic dimension? In the ethic of Chin's intention? In the ingenuity of his concept? In the physical arrangement of the plants? The challenge here is difficult, as it is in other eco-art projects. Critics generally evade the interpretive problem by considering such projects within existing categories such as environmental art or land art and then loading a set of prior aesthetic conventions onto them.

And what is the ecological aesthetic of Beuys's Social Sculpture? It has been described as a shift from museological concerns about the context of art to anthropological ones. "Creativity, to him, was a science of freedom. All human knowledge comes from art; the concept of science has evolved from creativity. And so it is that the artist alone is responsible for historical awareness; what counts is to experience the creative factor in history. History must consequently be seen sculpturally. History is sculpture."13 The concept has even been institutionalized in the Social Sculpture Research Unit, directed by artist Shelley Sacks at Oxford Brookes University in England. Sacks, who worked with Beuys, describes the projects initiated there as "instruments that involve ‘trans-actions' between people, issues and places. They are arenas for negotiation, creating shared currency and new forms of dialogue."14 What, then, is the basis for an aesthetic judgment? Is there a form to the organization of the workshops that invites aesthetic consideration? The central focus of the projects appears to be the creation of an experience for the participants. While Sacks does not present the projects as artworks, they derive from Beuys's intention to collapse the proverbial boundaries between art and life.

Critics have worked hard to fit Beuys's projects and others like Alan Sonfist's Time Landscape or Newton and Helen Harrison's Portable Farm: The Flat Pastures (1971-1972) into an art discourse when, in fact, the projects sometimes have more to do with other practices such as landscape architecture, design, or even biology. Part of the problem is that many artists want to participate in social processes or make statements about social situations in ways that transcend the conventional forms of representation that museums and galleries were originally created to house. Even as their projects avoid the commodity forms on which the art market depends, they are sometimes led to produce documentation that nevertheless conforms to the conventions of museum and gallery display as well as to the commodity demands of the art market.