IN AN ERA OF BLOCKBUSTER TRAVELING exhibitions, mass-merchandising museum shops and high-profile curatorial politics, the Barnes Foundation, housed in a limestone mansion in suburban Philadelphia, is one of the most striking -- and perplexing -- anomalies of the international art world. It is the repository of a fabled collection of Impressionist and Postimpressionist works (180 Renoirs, 69 Cezannes, 44 Picassos and numerous Seurats, Gauguins and Modiglianis). Yet because of the harshly restrictive policies of its embittered founder-patron, the Barnes has largely withheld its treasures from public view.
( Dr. Albert Barnes, a Philadelphia physician who made millions from an antiseptic he...