[metmom]

He does not usurp or substitute for the vagaries of fallible human choice.

Then there can be no claim of the church being kept from error in teaching of faith or morals.

[Mrs. Don-o]

That does not logically follow. The gift of infallibility does not guarantee that there will not be whackadoodle popes, but that the whackadoodle popes will not be permitted to impose their whackadoodle opinions on the whole Church as permanently binding de fide, on a matter of faith or morals.

Infallibility is not a power of popes; it is a protection from popes. It protects, not popes, but the Church.

Surely we all know that Christ gave promises of protection to the Church?

Two minutes: view and laugh.

Funny YouTube vid on infallibility