Deeply do I feel, ever will I protest, for I can appeal to the ample testimony of history to bear me out, that, in questions of right and wrong, there is nothing really strong in the whole world, nothing decisive and operative, but the voice of him, to whom have been committed the keys of the kingdom and the oversight of Christ's flock. That voice is now, as ever it has been, a real authority, infallible when it teaches, prosperous when it commands, ever taking the lead wisely and distinctly in its own province, adding certainty to what is probable and persuasion to what is certain. Before he speaks, the most saintly may mistake; and after it has spoken, the most gifted must obey….”
( From Newman’s Discourse on University Education, delivered in Dublin in 1852, & quoted by Newman in a letter to the Guardian on 12th Sept 1872. )