"If a pope clearly realizes that he is no longer physically, psychologically and spiritually capable of handling the duties of his office, then he has a right, and under some circumstances, also an obligation to resign," Benedict said.
The former Cardinal Joseph Ratzinger had an intimate view as Pope John Paul II, with whom he had worked closely for nearly a quarter-century, suffered through the debilitating end of his papacy.
Daniela Petroff contributed from Vatican City.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.