In the Catholic church, must the Pope clearly state,"I am now speaking infallibly", when he is addressing matters of doctrine? Or, is that assumed?
With respect to when a pope speaks infallibly, this was defined in Vatican I Council, in 1870. Specifically, the Catholic church said:
"We teach and define as a divinely revealed dogma that when the Roman pontiff speaks EX CATHEDRA, that is, when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, he defines a doctrine concerning faith or morals to be held by the whole church, he possesses, by the divine assistance promised to him in blessed Peter, that infallibility which the divine Redeemer willed his church to enjoy in defining doctrine concerning faith or morals. Therefore, such definitions of the Roman pontiff are of themselves, and not by the consent of the church, irreformable.”
Now, this doctrine of papal infallibility was controversial when issued. There was (and remains) much disagreement among Catholic theologians as to exactly when the pope is speaking “ex cathedra”. Personally, I leave the debate to them. I simply take at face value what Vatican I declared (infallibly, by the way). So, applying that as the criteria, I believe it is fair to say that when the pope speaks about faith or morals, he is doing so as pope (i.e., he is speaking in the exercise of his office). In so doing, what he says is a doctrine to be held by the whole church. What he says, therefore, is infallible.
To be fair, many Catholics would not agree with my view. They take a much more restricted view of infallibility. If I were a Catholic, I’d do the same thing for this very reason, because popes have spoken obviously unbiblical things regarding faith and morals over the years, which causes big problems for you if you are Catholic. They try to limit papal infallibility to “official” statements (whatever that means) issued by the pope as opposed to remarks he may make in speeches, such the one referred to in my article.
In my view, the pope doesn’t get a break on such a restricted view of infallibility. Think about what the statement from Vatican I says. The “infallible” teaching of Vatican I says that the pope, when he speaks on matters of faith and morals, is speaking by “divine assistance”. Therefore, it logically follows that whenever the pope speaks about faith and morals, he is doing so by the power of God (according to the Catholic church). If that is true, then by definition whatever he says regarding faith and morals must be “infallible”. One can’t have it both ways. Either the pope speaks about faith and morals by divine assistance, or he doesn’t. You cannot limit statements on faith and morals to “official” statements. If you do, then the implication is that there are times when the pope speaks about faith and morals fallibly. If that is true, then what Vatican I stated cannot be true. So, I believe that anytime the pope says anything related to faith and morals, he must be speaking “infallibly”.