I think he believes that God has kept him alive this long because God wills for him to be Pope, even if he is so infirmed.
Who says he can't run the Papacy effectively? It's the Pope's body that is failing not his mind. This saintly man is a witness to the dignity of life. What strength and courage he gives to those who are suffering from physical ailments. I think it was NYer who posted the Pope's comments from a few years back that "Jesus did not come down from the Cross".
Stolat to the Pope.
For other religions this would be a point of debate; however, The Holy Spirit guides His Church -His Church is not limited by the temporal -hence, debate is moot for all but nonbelievers...
Since when did you become an unimformed Catholic?