The crucifix, Roman instrument of torture and Christian emblem of redemption and divine love, is a powerful symbol. Remember the outcry when artist Andres Serrano dunked one in a glass of his own urine and then photographed it?

Serrano was trying to make a point about bodily fluids being prominent in Christian iconography, but many of his critics denounced his photograph - a beautiful if unorthodox image - as blasphemy.

That was in 1987, and the photograph, called Piss Christ, probably would still inflame religious and even some political sensibilities if exhibited in a public place.

Consider now the burning cross. If you saw one in an art gallery or museum, how would you instinctively respond? Probably with one or all of these words: Ku Klux Klan, bigotry, racism, outrageous, despicable, especially if next to the burnt crosses you saw a white Klan hood blazoned with authentic Klan badges.

But what if you learned that the artist who created these burnt crucifixes and the Klan hood was African American? Perhaps you would be confused or puzzled.

At the very least you would experience a moment of ambiguity, in which you might wonder, can a burning crucifix be something other than what the Klan intends, a symbol of segregation and racial intimidation?

That moment of ambiguity is what sculptor David Stephens is seeking in his exhibition at the Slought Foundation in West Philadelphia. The show contains a dozen small, charred crosses that were burned clandestinely and privately.

A secret ritual wasn't what Stephens intended. He wanted to burn the 18-inch-high crosses, made of wood wrapped in burlap, in a small plaza across the street from Slought, on Walnut Street just west of 40th Street. It would have been a public event, after which the crosses would have been reinstalled in the gallery.

The plaza is in front of a former Christian Science Church, now an arts venue called the Rotunda, that, like the Slought building, is owned by the University of Pennsylvania.

For reasons having to do with city fire codes - open burning not allowed except at barbecues - and the university's own prohibitions against open flames, that didn't prove feasible.

After searching for an alternative site, Slought director Aaron Levy, curator Osvaldo Romberg and Stephens decided to take the crosses to an unidentified location, most likely out of the city, where they could be burned "legally" and the process video-recorded.

This was done, and now visitors to the show can witness a cross-burning secondhand. The experience of seeing these kerosene-soaked crosses burst into flame and roar within seconds into a tent of fire is inherently powerful and disturbing. One can understand why the Klan adopted the fiery crucifix as a weapon.

Since the founding of the Klan after the Civil War, the primeval force of the flaming cross has been reinforced by its association with racial and religious intolerance, violence and even murder, which is why African Americans in particular find it so repugnant. However, they haven't been the only victims; crosses have been burned on the lawns of Jews and Catholics.

Yet as the video begins, viewers experience another sensation that perhaps they didn't anticipate; I certainly didn't. It's the immediate ambiguity of meaning.

What exactly does this cross-burning signify? It's clearly not a racist statement, so it must be either a commentary on Klan beliefs, or perhaps on the First Amendment, or an attempt by Stephens to redeem the cross as a positive emblem by denying the Klan its exclusive use.

In fact, all of these rationales come into play, although for the eight or nine minutes that it takes for the crosses to flame up, then gradually die down to embers, one is never entirely certain what to think.

The context of the exhibition helps. The 63-year-old Stephens has been making crucifix sculptures for some time. His solo exhibitions at Philadelphia's Gallery Joe and the Noyes Museum in Oceanville, N.J., last year included some layered crucifixes that seemed to leap into space.

They were also symbolically ambiguous; they might have expressed muscular, assertive Christianity or extreme suffering, either redemptive or cruel.

The Slought exhibition includes several similar sculptures of multiple crosses, but these aren't as powerful as the earlier ones. In this show, Stephens is more concerned with breaking the Klan's monopoly on the burning crucifix and neutralizing its negative connotations.

Stephens was moved to do this, he says, by a 2002 U.S. Supreme Court decision that affirmed the right of a person to burn a cross on private property if the burning was not intended to be racial intimidation.

The case originated in Virginia, where in 1998 two Pennsylvania Klan members, Barry and Byron Black, staged a cross-burning that was visible to neighbors and passing motorists. Stephens refers to this ruling in the show's largest piece, built around the 12 burnt crosses on the floor and a dozen large Braille panels on the wall behind them.

(Though blinded by glaucoma, Stephens fashions these panels himself.)

The panels re-create an imagined three-way "conversation" among the Blacks, an ancient queen of Ethiopia who reportedly introduced Christianity in that country, and biblical King Zedekiah's Ethiopian eunuch.

The Braille translates as gibberish because, as Stephens has explained, the principals "talk over" one another. In other words, it's impossible to resolve Klan beliefs with Scripture.

The burnt crucifixes on the floor offer mute, but not especially moving, testimony to this. The searing image on the video monitor animates the installation emotionally.

One can only imagine how much more provocative and confrontational this sculpture would be had it been executed as the artist intended. Stephens still hopes that such a "performance" will be possible.

"There's an art and performance park on Long Island, and I've thought of doing it there," he said while watching white smoke billow off the circle of crosses.

As Philadelphians recently learned, cross-burning is neither a quaint historical artifact nor a cultish backwoods phenomenon. In fact, Stephens' installation is strikingly timely.

The artist noted that, in September, two South Philadelphia men were arrested for attempting to intimidate a biracial couple with burning crosses. Police said the men openly discussed their intentions (ironically, at a backyard barbecue). After failing to ignite a cross traced with lighter fluid on the sidewalk in front of the couple's house, they burned two crosses of spray foam insulation.

"The sensitivity about the issue of cross-burning is not unfamiliar to us," Slought director Levy said. "We're trying to raise discussion of the issues in a way that perhaps would insulate it from controversy."