Pope Francis says his predecessor, Benedict XVI, was courageously following his conscience when he decided to retire.
Benedict became the first pontiff in 600 years to quit the post when he resigned in February, paving the way for Francis' election as pope two weeks later.
Francis told pilgrims and tourists in St. Peter's Square on Sunday that God made Benedict understand through prayer the step he had to take.
Benedict explained when announcing his intention to resign that he felt he didn't have the mental and physical strength to continue as pontiff.
The rare resignation dismayed some traditionalists in the Catholic church. But Francis praised Benedict for following "his conscience with a great sense of acumen and courage."
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Pope Francis has told churchmen to shun the "logic of human power" as he tries to rid the Vatican's power structures of corruption and other wrongdoing.
Francis in a homily Saturday in St. Peter's Basilica also warned his church of the "danger of thinking in a worldly way."
The admonition comes a day after Italian authorities arrested a Vatican accountant in a probe of an alleged attempt to smuggle millions of dollars from Switzerland into Italy. In the latest scandal tainting the church, the Italian prelate is also under investigation in a separate money-laundering probe.
Separately, an Italian cardinal, Velasio de Paolis, told Rome daily Il Messaggero that the Vatican "must clean house," adding Francis is right to pursue his anti-corruption campaign within church hierarchy.
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