But the Catholic owes submission also to the non-infallible teachings; and not only an outer submission, a reverent silence, that offends not either verbally or in writing against the decision rendered, but he owes also his inner assent. But it cannot be that unconditional inner assent which he owes to the infallible decision, for this he holds to be irrevocably certain; nor is his assent to non-infallible decisions a real act of faith. He is not given any unconditional guarantee of the truth. An error is, of course, most unlikely, but not absolutely impossible. Hence the faithful Catholic should always be ready to accept such decisions in as far as they are warranted by recognized truth. This applies to all kinds of doctrinal teaching, but of course in different ways, corresponding to the degree of authority,—for instance, Papal decisions are of higher authority than those of the Congregations,—yet it applies also to the doctrinal decisions of the Congregations, because they are the ordinary teaching organs of the Church. When the Congregation of the Index, 1857, had forbidden the works of _Guenther_ and many thought they could evade the decision, _Pius IX._ wrote, June 15, to the Archbishop of Cologne: “The decree is so far-reaching that nobody may think himself free not to hold what we have confirmed.” Similar was what the Pope had written to the Archbishop of Mecheln after the condemnation of the ontological errors of _Ubagh_. The Motu proprio of _Pius X._ of November 8, 1907, speaks similarly of the obligation of submission to the decisions of the Papal Biblical Commission relating to doctrines, and to the decrees of Congregations when approved by the Pope. (Cf. also the Syllabus of Pius IX., sent. 22.) Theologians agree that this requisite internal assent is not the same as irrevocable assent. This was also declared by _Pius IX._ in his letter to the Archbishop of Munich-Freising, saying that this inner submission is by no means faith; and no theologian will ascribe infallibility to a mere congregational decree. (See on this point: _e.g._ _Grisar_, Galileistudien, 1882, 171 _seq._ Cr. _Pesch_, Theol. Zeitfragen, Erste Folge, 1900, III. _Egger_, Streiflichter ueber die freiere Bibelforschung, 1889.)