A scholar has suggested that "Laocoön," a fabled sculpture whose unearthing in 1506 has deeply influenced thinking about the ancient Greeks and the nature of the visual arts, may well be a Renaissance forgery - possibly by Michelangelo himself. Her contention has stirred some excitement and considerable exasperation among art historians in the Classical and Renaissance fields. Many other challenges to accepted attributions have faded quickly into oblivion. The scholar advancing the theory, Lynn Catterson, a summer lecturer in art history at Columbia University, presented her argument in a talk at the university's Italian Academy for Advanced Studies in America...