St. John Henry Newman
Grammar of Assent
Part 1 › Chapter 5 · Part 7 of 7
Belief in the Holy Trinity
I say, "granting these various propositions are virtually contained in the revealed word," for this is the only question left; and that it is to be answered in the affirmative, is clear at once to the Catholic, from the fact that the Church declares that they really belong to it. To her is committed the care and the interpretation of the revelation. The word of the Church is the word of the revelation. That the Church is the infallible oracle of truth is the fundamental dogma of the Catholic religion; and "I believe what the Church proposes to be believed" is an act of real assent, including all particular assents, notional and real; and, while it is possible for unlearned as well as learned, it is imperative on learned as well as unlearned. And thus it is, that by believing the word of the Church implicitè, that is, by believing all that that word does or shall declare itself to contain, every Catholic, according to his intellectual capacity, supplements the shortcomings of his knowledge without blunting his real assent to what is elementary, and takes upon himself from the first the whole truth of revelation, progressing from one apprehension of it to another according to his opportunities of doing so.
Source: Grammar of Assent (Newman Reader)