Dear Dr. Boli: The news media (by which I mean KDKA, which is the only station my old Philco radio gets) keep saying that the resignation of Benedict XVI sets a “precedent.” Is that true? What does it mean? —Sincerely, Raoul Castro, Havana (North Dakota).

Dear Sir: It means simply that other people in positions of power who find their labors more difficult than they anticipated will now feel empowered to step down. Already we see the effect of the precedent in Pittsburgh’s Mayor Luke Ravenstahl, who suddenly refused to run as the machine candidate for mayor, explaining that he had stopped enjoying politics because sometimes people were mean to him. The difference is that the Vatican knows exactly what to do when a pope retires, but no one has any idea what to do when the machine candidate for mayor of Pittsburgh drops out at the last minute. Right now the Vatican is cheerfully implementing the Celestine Protocol, but in a smoke-filled room somewhere near the City-County Building in Pittsburgh there are men praying sincerely for a comet to strike the earth before the primaries in May.