Today shock can seem indistinguishable from scandal, less a side effect of artistic innovation than a ploy ginned up by self-promoting artists and public scolds. But many artists say that generating shock remains the duty of anyone who aims to reflect the real world back at itself. Audiences may be more sophisticated, and jaded, but it is still possible to show them something they may not want to see. “Conditions in society are shocking, and art really does become a mirror to society in that way,” said the performance artist Karen Finley, who became a national symbol for shock art during the early 1990s battles over public funds for controversial art. And sometimes that mirror turns into a magnifying glass. The furor over her politically charged work — which included smearing her body with chocolate and stuffing orifices with yams, to illustrate society’s degradation of women — had less to do with the work itself, she said, than the culture warriors who seized on it to advance their own agenda.

“You can’t just say, ‘I’m going to go out and try to shock people,’ ” she said. “It’s usually a much more subtle matter of time and place.”

The filmmaker John Waters began his 1981 autobiography, “Shock Value,” with the declaration that having someone vomit while watching one of his movies was “like getting a standing ovation.” But mere shock for shock’s sake, he said recently, is “deathly.”

“If you’re shocking by subject matter alone, it’s not enough, and it never was enough,” he said. “It’s easy to shock, but it’s much harder to surprise with wit.”