[The Catholic Church] professes to be built upon facts, not opinions; on objective truths, not on variable sentiments; on immemorial testimony, not on private judgment; on convictions or perceptions, not on conclusions. None else but she can make this profession. … Her precision and peremptoriness, all that is laid to her charge as intolerance and exclusiveness, her claim entirely to understand and to be able to deal with her own deposit and her own functions; her claim to reveal the unknown and to communicate the invisible, is, in the eye of reason (so far from being an objection to her coming from above), the very tenure of her high mission,—just what would be sure to characterise her if she had received such a mission. She cannot be conceived without her message and her gifts. She is the organ and oracle, and nothing else, of a supernatural doctrine, which is independent of individuals, given to her once for all, coming down from the first ages, and so deeply and intimately embosomed in her, that it cannot be clean torn out of her, even if you should try; which gradually and majestically comes forth into dogmatic shape, as time goes on and need requires, still by no private judgment, but at the will of its Giver, and by the infallible elaboration of the whole body;—and which is simply necessary for the salvation of every one of us.
This then is the special glory of the Christian Church, that its members do not depend merely on what is visible, they are not mere stones of a building, piled one on another, and bound together from without, but they are one and all the births and manifestations of one and the same unseen spiritual principle or power, “living stones,” internally connected, as branches from a tree, not as the parts of a heap. They are members of the Body of Christ. That divine and adorable Form, which the Apostles saw and handled, after ascending into heaven became a principle of life, a secret origin of existence to all who believe, through the gracious ministration of the Holy Ghost. This is the fruitful Vine, and the rich Olive tree upon and out of which all Saints, though wild and barren by nature, grow, that they may bring forth fruit unto God.
To [the Church] 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 … 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.