Wherefore a man can know nothing by himself, save after a natural manner, which is only that which he attains by means of the senses. For this cause he must have the phantasms and the forms of objects present in themselves and in their likenesses; otherwise it cannot be, for, as philosophers say: Ab objecto et potentia paritur notitia. That is: 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.
–John of the Cross
(1542 - 1591)