If Catholic confessional state encyclicals are not infallible then so-called Catholic social teachings are not infallible

https://www.thepublicdiscourse.com/2018/07/22105/

But not everything the pope teaches is taught ex cathedra. On the contrary, virtually everything the pope teaches is not taught ex cathedra. The standard examples of papal teachings that are not ex cathedra are teachings of the popes in their encyclicals. Thus, Sixtus Cartechini, in his standard work De Valore Notarum Theologicarum says that “everything found in encyclicals and other official documents” (emphasis in original) “can be said to be doctrina catholica.” Francis J. Connell, probably John Courtney Murray’s fiercest critic before the Second Vatican Council, says that “besides the infallible teaching of the Church on matters concerning revelation or connected with it, there are also pronouncements of her official teachers which are authoritative though not infallible,” and “the statements of the Sovereign Pontiff in Encyclicals are usually of this category.” Indeed, Pius XII says in Humani Generis that “in Encyclical Letters . . . the Popes do not exercise the supreme power of their Teaching Authority.” So, prima facie, whatever Gregory, Pius, and Leo said about the confessional state in their encyclicals is doctrina catholica, not de fide. 

Exceptions are possible, however, and many nineteenth-century theologians (including such greats as Louis Billot and John Henry Newman) thought at least some teachings in Pius IX’s 1864 encyclical Quanta Cura were ex cathedra (they generally did not say which). This, however, is untenable. Pius IX taught ex cathedra in his bull Ineffabilis Deus (1854) defining the dogma of the Immaculate Conception, and Quanta Cura is nothing like Ineffabilis Deus. In the latter, Pius expressly stated he was “defin[ing] a dogma of the Catholic faith,” and he invoked “the authority of Jesus Christ our Lord, of the Blessed Apostles Peter and Paul, and . . . [his] own authority” to “declare, pronounce, and define” a doctrine that was “revealed by God” and must “be believed firmly and constantly by all the faithful.” Pius XII, in defining the dogma of the Assumption in Munificentissimus Deus (1950), used similar language. In Quanta Cura, however, Pius IX invokes merely his “apostolic authority” to “reprobate, proscribe, and condemn” all the “evil opinions and doctrines severally mentioned in this letter,” which the reader must then hunt up for himself elsewhere in the document. Moreover, Pius never actually says that any of the condemned propositions is heretical (the opposite of de fide), leaving open the possibility that they are wrong in some lesser way (such as being “proximate to heresy,” “erroneous,” or “rash”—the so-called lesser theological censures). Under Canon 749-3, “No doctrine is understood as defined infallibly unless this is manifestly evident.” Quanta Cura does not come close. Much less do any of the other nineteenth-century encyclicals on the confessional state. 

Moreover, the infallible magisterium extends only to matters “divinely revealed,” things closely connected thereto, and the principles of the natural law. Since the doctrine of the confessional state involves duties owed to the Church, it is obviously not part of the natural law. Moreover, there is no hint of such a doctrine in scripture, and nothing like it appears in tradition until many centuries after the time of the apostles. Accordingly, none of the popes teaching this doctrine ever claimed it was divinely revealed (or closely connected to anything so revealed). Therefore, the infallible magisterium does not extend to this doctrine. That does not mean that the Church may not teach on such questions—it certainly may, just as it may teach on other social and political issues—but such teachings cannot be infallible and so cannot be de fide. 

Thus, the teaching on the confessional state in the nineteenth-century encyclicals is exactly what it appears to be—doctrina catholica and not de fide. Catholics were never required to believe it in faith, but they were required to give it a religious submission of intellect and will. 

The Magisterial Authority for the Secular State 

Doctrina catholica can be abrogated by later teaching, and that is exactly what happened to the teaching on the confessional state when the Second Vatican Council taught contrary doctrines in Dignitatis Humanae, its Declaration on Religious Freedom. [https://www.thepublicdiscourse.com/2018/07/22105/]