Tertullian

“ We see, then, that in opposition to the bodily senses another faculty is provided of a much more serviceable character, even the powers of the soul, which produce an understanding of that truth whose realities are not palpable nor open to the bodily senses, but are very remote from men’s everyday knowledge, lying in secret—in the heights above, and in the presence of God Himself. ”

“ If, however, corporeal things are perceived by the soul, then it follows that the soul’s power is an intellectual one, and not merely a sensuous faculty; for while it perceives it also understands, because without understanding there is no perceiving. And then, again, by what are incorporeal things understood? If it is by the mind, [8] where will be the soul? If it is by the soul, where will be the mind? For things which differ ought to be mutually absent from each other, when they are occupied in their respective functions and duties. ”

“ The truth is, that whenever a man is out of his mind, [10] it is his soul that is demented—not because the mind is absent, but because it is a fellow-sufferer (with the soul) at the time. [11] Indeed, it is the soul which is principally affected by casualties of such a kind. Whence is this fact confirmed? It is confirmed from the following consideration: that after the soul’s departure, the mind is no longer found in a man: it always follows the soul ”

“ That the intellect is not to be preferred above the senses, on the (supposed) ground that the agent through which a thing exists is inferior to the thing itself; and (2) that the intellect must not be separated from the senses, since the instrument by which a thing’s existence is sustained is associated with the thing itself. ”

“ It is a fact, that these truths are learned by means of palpable forms; in other words, invisible things are discovered by the help of visible ones, even as the apostle tells us in his epistle: “For the invisible things of Him are clearly seen from the creation of the world, being understood by the things that are made;” ”

“ For in this philosophy lie both their Æons and their genealogies. Thus, too, do they divide sensation, both into the intellectual powers from their spiritual seed, and the sensuous faculties from the animal, which cannot by any means comprehend spiritual things. ”