"Stewardship" - the notion that collectively and individually, people ought to act as enlightened managers rather than owners of property - is a term that pops up any time people debate environmental land-use issues.

But the concept doesn't mesh with our legal system, which instead concentrates on the penalties for trespass, a noted expert on natural resource law said Thursday.Joseph Sax, a professor of law at the University of California, Berkeley, said during his Natural Resources Law Forum talk at the University of Utah College of Law that under the body of law governing property, "You may not do harm - but you need not do good."

And that, he said, needs to change, so that society as a whole may profit from the beauty as well as the utility of property.

Sax, considered a founder of modern environmental law, said that in the late 1870s, English lawmakers set two important precedents: first, that the government is responsible for protecting culturally valuable property, whether publicly or privately owned; and second, that pressure should be brought on owners to take care of such property.

The law's weakness, however, was that the government would only act in the face of a threat. Trespass could be restricted or punished, but there was no impetus to good stewardship for its own sake.

Earlier thinkers and writers had explored the notions of stewardship before English lawmakers considered them, Sax said. The concept of public property surfaced during the French Revolution, and 19th-century writer Victor Hugo, decrying the destruction of historic buildings, pointed out that a building's utility might belong to its owner, but its beauty belongs to everyone.

To discuss property in these terms, Sax said, is to shift it from the realm of space - its physical presence and immediate value - to the realm of time by recognizing that part of the past exists in the present and that it has public value beyond what an owner might claim.

"One might own (Sir Isaac) Newton's notebooks but not the knowledge they contain," said Sax, suggesting that the legal system can look at this "heirloom" law to frame a new body of natural resource law.