Is Cum Ex Apostolatus Officio Infallible?

On page 395, they quote from my book, 54 Years that Changed the Catholic Church: “This Bull of Pope Paul IV deserves special consideration, especially in light of the fact that it has been ignored by many. … this Bull appears in the Fontes of the Code of Canon Law in several places.  It is considered infallible because it teaches on a matter of faith.”

They devote pages 395 to 407 to the question of Cum Ex Apostolatus Officio. Click through here for various translations.

Their conclusion is that it is not infallible, and they question whether it even still applies as a law.

Their biggest omission is an article published in Si Si No No of the Society of Saint Pius X, which states: “The very particular nature of the pope’s Ordinary Infallible Magisterium was quite clear until Vatican I. While this Council was in session, La Civiltà Cattolica, which published (and still publishes) under the direct control of the Holy See, replied in these words to Fr. Gratry, who had criticized Pope Paul IV’s Bull Cum ex Apostolus: We ask Fr. Gratry, in all serenity, whether he believes that the Bull of Paul IV is an isolated act, so to speak, or an act that is comparable to others of the same kind in the series of Roman popes. If he replies that it is an isolated act, his argument proves nothing, for he himself affirms that the Bull of Paul IV contains no dogmatic definition. If he replies, as he must, that this Bull is, in substance, conformable to countless other similar acts of the Holy See, his argument says far more than he would wish. In other words, he is saying that a long succession of Roman popes have made public and solemn acts of immorality and injustice against the principles of human reason, of impiety towards God, and of apostasy against the Gospel (vol.X, series VII, 1870, p.54).”

What this means is that they do not believe Cum Ex Apostolatus Officio itself is infallible, but that the principles in it are infallibly true, because they are part of the Ordinary Magisterium of the Catholic Church, being “in substance, conformable to countless other similar acts of the Holy See.”

They also propose that this Bull is not contained in the Code of Canon Law.

6. 1. As regards laws published prior to the Code, the general rule is that all former laws, whether particular (for instance, for a certain country, for a Religious Order, etc.) or universal, that conflict with the laws of the Code, are abolished, unless the Code explicitly rules otherwise in reference to any special law. (Canon 6, 1.)
2. Canons of the Code that restate former laws exactly as they were before, must be interpreted according to the approved and accepted interpretation of commentators on the old law. Canons which agree only in part with the former law are to be interpreted like the former law in the points in which they agree; but in the points in which the new law differs from the former they must be judged by their wording and context. When it is doubtful whether a law of the new Code differs from the old law, one must not deviate from the former law. (Canon 6, 2, 3, 4.)
3. All former ecclesiastical punishments, whether spiritual or temporal, corrective or punitive, latae or ferendae sententiae, of which the Code makes no mention, are held to be abolished. (Canon 6, 5.)
4. All other disciplinary laws which have been in force up to the present time cease to be binding, unless they are explicitly or implicitly contained in the Code. The laws contained in the approved liturgical books, however, remain in force. This part of the Canon refers to the common law of the Church, for the Code states in Canon 22 that particular laws, namely for dioceses, individual countries, Orders, are to remain in force unless they are opposed to the laws of the Code. (Canon 6, 6.)