Today is the feast of St. Juan de la Cruz, Doctor of the Church. From his Ascent of Mount Carmel (Book II, Chapter III):
From the object that is present and from the faculty, knowledge is born in the soul. Wherefore, if one should speak to a man of things which he has never been able to understand, and whose likeness he has never seen, he would have no more illumination from them whatever than if naught had been said of them to him. I take an example. If one should say to a man that on a certain island there is an animal which he has never seen, and give him no idea of the likeness of that animal, that he may compare it with others that he has seen, he will have no more knowledge of it, or idea of its form, than he had before, however much is being said to him about it. And this will be better understood by another and a more apt example. If one should describe to a man that was born blind, and has never seen any colour, what is meant by a white colour or by a yellow, he would understand it but indifferently, however fully one might describe it to him; for, as he has never seen such colours or anything like them by which he may judge them, only their names would remain with him; for these he would be able to comprehend through the ear, but not their forms or figures, since he has never seen them.
Even so is faith with respect to the soul; it tells us of things which we have never seen or understood, nor have we seen or understood aught that resembles them, since there is naught that resembles them at all. And thus we have no light of natural knowledge concerning them, since that which we are told of them bears no relation to any sense of ours; we know it by the ear alone, believing that which we are taught, bringing our natural light into subjection and treating it as if it were not. For, as Saint Paul says, Fides ex auditu. As though he were to say: Faith is not knowledge which enters by any of the senses, but is only the consent given by the soul to that which enters through the ear.
