NEW YORK — U.S. Supreme Court Justice Antonin Scalia said Thursday there is clearly a difference between pornography and obscenity, but that it will never be clear what exactly that difference is, highlighting the backbone of a legal ambiguity that pervades the adult entertainment industry and also, according to Scalia, essentially guarantees its protection.

Scalia was speaking at a symposium on the arts hosted by the Juilliard School when he made the remark, harkening back to the famous quote from Justice Potter Stewart in 1964 that said he wouldn’t attempt to define pornography but he knew it when he saw it.

“The line between protected pornography and unprotected obscenity lies between appealing to a good healthy interest in sex and appealing to a depraved interest, whatever that means,” Scalia said, clarifying his own difficulty with interpreting the law.

But Scalia said the end result is that every small town in America must “tolerate the existence of a porn shop.”

Scalia went on to say that there are times when the government’s control over pornographic content is absolute, specifically when “art” is funded through government institutions such as the National Endowment for the Arts.

Referencing controversial homoerotic photographs by Robert Mapplethorpe and Andres Serrano’s “Piss Christ,” which shows a crucifix in a vat of urine, Scalia said the government couldn’t be accused of censorship if it decides to pull the plug on art that it is in effect paying for.

“The First Amendment has not repealed the ancient rule of life, that he who pays the piper calls the tune,'' Scalia said.

The NEA was created in 1965 to subsidize artists, but has met with the contention of many conservatives who argue that it finances obscenity.

“I can truly understand the discomfort with government making artistic choices, but the only remedy is to get government out of funding,” he said.

Shortly after Serrano published his controversial photographs, Congress passed a law that required the NEA to consider decency when it funded art programs. The law was challenged in 1998 but the Supreme Court ruled the government could employ a “decency standard” for funding.