Every weekday, at 15 minutes past noon, the bronze doors of Rome's Pontifical Gregorian University swing open. Four hours of lectures in Latin have just ended, and as the 2,600 students at the world's largest Roman Catholic seminary pour down the marble steps of "the Greg," a babble of a dozen languages fills the air. Germans, known in Rome as gamberi rossi (red lobsters) because of their flaming scarlet cassocks, mingle with purple-clad Scots, Latin Americans in black robes and blue sashes with seminarians from the U.S. in black soutanes with red-andblue cinctures.
Every year more than 7.000 clerical students...