This may be proved in three ways. The first…
Two more Chapters this week, and fairly easy ones (for those who have studied since the beginning). We come to an exciting Chapter next week: how does the immaterial intellect contact the body?
Chapter 66 Against those who maintain that intellect and sense are the same. (alternate translation) We’re still using the alternate translation this week.
1 Thinking that there was no difference between intellect and sense, some of the early philosophers were close to the persons referred to above. But that notion of theirs is impossible.
2 For sense is found in all animals, whereas animals other than man have no intellect. This is evident from the fact that the latter perform diverse and opposite actions, not as though they possessed intellect, but as moved by nature, carrying out certain determinate operations of uniform character within the same species; every swallow builds its nest in the same way. Therefore, intellect is not the same as sense.
Notes It is a good joke to say you never see swallows down the Home Depot on a weekend. See also this Ed Feser article “Da Ya Think I’m Sphexy?” about the determinate behavior of animals.
3 Moreover, sense is cognizant only of singulars; for every sense power knows through individual species, since it receives the species of things in bodily organs. But the intellect is cognizant of universals, as experience proves. Therefore, intellect differs from sense.
Notes The “common sense” takes the input from the disparate senses and paints a picture, a unified whole, which the intellect considers. The intellect knows universals, which cannot be sensed. As the next paragraph emphasizes.
4 Then, too, sense-cognition is limited to corporeal things. This is clear from the fact that sensible qualities, which are the proper objects of the senses, exist only in such things; and without them the senses know nothing. On the other hand, the intellect knows incorporeal things, such as wisdom, truth, and the relations of things. Therefore, intellect and sense are not the same.
5 Likewise, a sense knows neither itself nor its operation; for instance, sight neither sees itself nor sees that it sees. This self-reflexive power belongs to a higher faculty, as is proved in the De anima [III, 2]. But the intellect knows itself, and knows that it knows. Therefore, intellect and sense are not the same.
6 Sense, furthermore, is corrupted by excess in the sensible object. But intellect is not corrupted by the exceedingly high rank of an intelligible object; for, indeed, he who understands greater things is more able afterwards to understand lesser things. The sensitive power therefore differs from the intellective.
Notes Bright lights overwhelm, blinding insights do not (and now you understand the metaphor).
Chapter 67 Against those who hold that the possible intellect is the imagination. (alternate translation) We’re still using the alternate translation this week.
1 The opinion of those who asserted that the possible intellect is not distinct from the imagination was akin to the notion just discussed. And that opinion is evidently false.
2 For imagination is present in non-human animals as well as in man. This is indicated by the fact that in the absence of sensible things, such animals shun or seek them; which would not be the case unless they retained an imaginative apprehension of them. But non-human animals are devoid of intellect, since no work of intellect is evident in them. Therefore imagination and intellect are not the same.
Notes A mental picture produced by sensation of a possibility is not apprehension of a universal. As the next paragraph emphasizes. If you’re stuck for something incorporeal to use as an example, pick a number, any number.
3 Moreover, imagination has to do with bodily and singular things only; as is said in the De anima [3], imagination is a movement caused by actual sensation. The intellect, however, grasps objects universal and incorporeal. Therefore, the possible intellect is not the imagination.
4 Again, it is impossible for the same thing to be mover and moved. But the phantasms move the possible intellect as sensibles move the senses, as Aristotle says in De anima III [7]. Therefore, the possible intellect cannot be the same as the imagination.
Notes Phantasm, the mental image provided by distillation of the senses using the bodily apparatus. (Wow.)
5 And again. It is proved in De anima III [4] that the intellect is not the act of any part of the body. Now the imagination has a determinate bodily organ. Therefore, the imagination is not the same as the possible intellect.
6 So it is that we read in the Book of Job (35:11): “Who teaches us more than the beasts of the earth, and instructs us more than the fowls of the air.” And by this we are given to understand that man is possessed of a power of knowledge superior to sense and imagination, which are shared by the other animals.