Epistemology Of Aquinas

These are the immaterial substances. Therefore Augustine concludes that the mind is able to understand these immaterial substances.
             The second objection presented appertains to the declaration that like is known by like. It is said that the human mind is more akin to the immaterial rather than material things wherefore by its own nature is immaterial. Given that the human mind understands material things, it should be able to understand immaterial things all the more.
             The third objection offers the claim that the fact that objects that are in themselves most sensible are not most felt by us, comes from sense being corrupted by their very excellence. The intellect, on the other hand, is not subject to such a corrupting influence from its very object. For this reason, things that are in themselves in the highest degree of intelligibility are likewise to us most intelligible. However, as material things are only intelligible by the process of abstraction from their material conditions, it is apparent that those substances are more intelligible whose very natures are immaterial. Therefore it seems that they are much more known to us than are material substances.
             In the fourth objection Aquinas turns to the Commentator's argument that nature itself would be frustrated in its very end were we unable to understand abstract substances, because it would mean that what was made to be in itself naturally intelligible not able to be understood at all. He affirms that in nature nothing is idle or purposeless, therefore it would seem that immaterial substances could be understood by the human intellect.
             The fifth and final objection is presented as a sort of analogy in that as sense is to the sensible, so is the intellect to the intelligible. It is given that our sight can see all things corporeal, whether they are superior and incorruptible, or lower and incorruptible.