[armydoc]

True, ratification of a synod is not required, but general, perhaps informal, consensus of the Magisterium is required, I believe.

Negative. The Church teaches that the Pope, by his office, enjoys infallibility apart from approval or consensus of any other person or council, formal or informal. Do you have any information to the contrary?

[annalex]

Thnak you, Doc.

I stand corrected to my 34. The Pope may teach infallibly without consent, formal or informal, of the Magisterium. Vatican II teaches that infallibility is a charism the pope "enjoys in virtue of his office, when, as the supreme shepherd and teacher of all the faithful, who confirms his brethren in their faith (Luke 22:32), he proclaims by a definitive act some doctrine of faith or morals. Therefore his definitions, of themselves, and not from the consent of the Church, are justly held irreformable, for they are pronounced with the assistance of the Holy Spirit, an assistance promised to him in blessed Peter."

(Papal Infallibility, a very accessible booklet on the matter)