Summa contra Gentiles2.96 Chapter XCVI. That separate substances do not gather their knowledge from sensibles

From what has been laid down it may be shown that separate substances do not receive intellective knowledge from sensible things.

For sensibles by their very nature are adapted to be apprehended by the sense, as intelligibles by the intellect. Wherefore every substance that is capable of knowledge, and derives that knowledge from sensibles, is endowed with sensitive cognition; and consequently has a body united to it naturally, since sensitive knowledge is impossible without a bodily organ. But separate substances have not a body naturally united to them, as we proved above. Therefore they do not derive intellective knowledge from sensible things.

Moreover. A higher power must needs have a higher object. Now the intellective power of a separate substance is higher than that of the human soul: since the human soul’s intelligence is the lowest in the order of intellects, as we proved above. And the object of the human soul’s intelligence is a phantasm, as stated above and this is higher in the order of objects than a sensible thing existing outside the mind, as appears from the order of cognitive powers. Consequently the object of a separate substance cannot be a thing existing outside the mind, as the direct object whence it derives its knowledge; nor can it be a phantasm. It follows, in consequence, that the object of the separate substance’s intellect is something higher than a phantasm. Now, nothing is higher than a phantasm, in the order of knowable objects, save that which is intelligible actually. Wherefore separate substances do not derive intellectual knowledge from sensibles, but they understand things which are intelligible even in themselves.

Again. The order of intelligibles is in accordance with the order of intellects. Now things intelligible in themselves are, in the order of intelligibles, above those things which are not intelligible but for the fact that we make them intelligible: and such must needs be all intelligibles taken from sensibles; because sensibles are not in themselves intelligible. But such are the intelligibles which our intellect understands. Therefore the intellect of the separate substance, since it is above our intellect, does not understand intelligibles received from sensibles, but it understands those which are intelligible actually.

Moreover. The mode of a thing’s proper operation is in keeping with the mode of that thing’s substance and nature. Now a separate substance is an intellect existing by itself and not in a body. Consequently, its intellectual operation will be directed to intelligibles that are not founded on a body. But all intelligibles taken from sensibles are some- Ch. xci.

what founded on bodies, for instance our intelligibles are founded on the phantasms which are in bodily organs. Therefore separate substances do not derive knowledge from sensibles.

Eurther. Just as primary matter is the lowest in the order of things sensible, and is consequently only in potentiality to all sensible forms, so the possible intellect, being the lowest in the order of things intelligible, is in potentiality to all intelligibles, as is clear from what has been said. Now those things which, in the order of sensibles, are above primary matter, have their form actually, whereby they are established in sensible being. Therefore separate substances, which, in the order of intelligibles, are above the human possible intellect, are actually in intelligible being; for the intellect that receives knowledge from sensibles is in intelligible being not actually, but potentially. Therefore a separate substance does not receive knowledge from sensibles.

Again. The perfection of a higher nature does not depend on a lower nature. Now the perfection of separate substances, since they are intellectual, consists in understanding. Therefore their understanding does not depend on sensible things, in such a way as to derive knowledge from them.

Hence it is evident that in separate substances there is not an active and a possible intellect, except perhaps in an equivocal sense. Because a possible and an active intellect are found in the intellective soul forasmuch as it derives its knowledge from sensibles: since it is the active intellect that makes the species received from sensibles to be actually intelligible, and the possible intellect is that which is in potentiality to the knowledge of all forms of sensible things. Wherefore, since separate substances do not derive their knowledge from sensibles, there is not in them an active and a possible intellect. Hence Aristotle {3 De AnimaY in establishing the possible and active intellects, states that we need to place them in the soul.

It is also evident that in these same substances local distance cannot hinder the knowledge of separate substances. For local distance is per se referable to sense, and not to the intellect except accidentally, in so far as it receives from sense, because sensibles move the senses at a determinate distance. Now things intelligible actually, in so far as they move the intellect, are not in place, for they are separate from corporeal matter. Since then separate substances do not derive intellective knowledge from sensibles, local distance has no effect on their knowledge.

Again, it is clear that time has nothing to do with their intellectual operation. For just as things actually intelligible are apart from place, so are they apart from time; because time is consequent upon local movement; wherefore it measures only such things as are somehow in place. Consequently the understanding of a separate substance transcends time: whereas time is incidental to our intellectual operation, since we derive our knowledge from phantasms which relate to a determinate time. Hence it is that in composition and division our intellect always includes time past or future, but not in understanding what a thing is. For it understands what a thing is by abstracting intelligibles from sensible conditions: wherefore, in respect of that operation, it understands the intelligible apart from time and all conditions of things sensible. Whereas it composes and divides by applying previously abstracted intelligibles to things, and in this application time must of necessity be implied.