[quote=otm]Keep in mind that there are three forms infallible statements can take: ex cathedra (literally "from the chair; a definition given by the Pope); daoctrine defined through a council and, if the Pope is not present at the council, ratified by him; and the third, which is the continual magisterial teaching of the church (such as the issue of abortion; not defined or declared by either a Pope or a council, but continually taught by the Church from the earliest times).
Or perhaps I should not say three forms, but three ways an infallible statment could be made.
There was much discussion as to whether or not John Paul 2’s statement about the impossibility of ordaining women was ex cathedra; and although some have tried their mightiest to say it is (some taking the position that it is, and prove it is not, almost), the generally accepted answer to that is that it is simply a statement confirming a 2000 year held truth; that is, the statement is infallible, but not because of an ex cathedra statement, but because it has been a continually held truth since the beginning of the Church.
That is the best answer I have ever gotten about infallibility.
I found this reference from a Catholic site,
Matt. 26:70-72; Mark 14:68-70; Luke 22:57; John 18:25-27 - Peter denied Christ three times, yet he was chosen to be the leader of the Church, and taught and wrote infallibly.
Here the Catholic site says that Peter taught and wrote infallibly, now prior to your answer I have had a hard time in this teaching because it seems that the Church has spoken ex cathedra only 9 times or less.
Again thanks for your solid answer!