I'm going to jump into snark-infested waters and give you my reason.
The Pope is God incarnate and God can over-ride any previous commands. Think of the nuns as today's Vestal Virgins of yore.
28 posted on 01/19/2014 11:37:01 AM PST by Jack Hydrazine
(Pubbies = national collectivists; Dems = international collectivists; me = independent conservative)