Saint Thomas Aquinas provided a theory on the intellectual soul. He believes that this soul is in fact a non bodily thing since it can potentially cognize all bodies, something that can only be done if you possess none of it. Aquinas is incorrect in this though since his understanding of thinking makes it apparent that the intellect is finite not infinite. Due to the need of phantasms to produce ideas the intellect can never be able to cognize all things due to the limitations of matter, that produces phantasms, thus making it not necessary that the soul be immaterial.
According to Aquinas the intellectual soul is non- bodily since it can potentially cognize all bodies. He states that anything that is made of matter suffers due to its own natural predispositions. This means that a body can only know that which it is determined to know, thus an eye is only able to see but is not able to smell. Additional limitations may be place upon the matter ...view middle of the document...
As stated above, Aquinas believes that matter is unable to completely or perfectly understand a situation do to natural deficiencies. If something is deficient in some way then it means that it is incapable of fully doing something. Since the deficient body uses its sense to create the phantasms, which are necessary for thought, than the intellect cannot cognize all things even potentially since it is limited to that which the body can sense. If something is impossible to do than there is no potential to do. For example a man with no legs does not posses the potential to walk on his own legs since he has none. Thus the soul is limited to know only that which exists within the capabilities of the body.
If the soul cannot cognize all things then the soul does not have to be immaterial. Aquinas believes that the soul is immaterial since to know all matter it must have none. But do to how human thought is to occur according Aquinas than this is incorrect. If the soul is limited to the phantasms then it can never know of all matter. Therefore it is not necessary that the soul be immaterial since it still cannot know of all matter. All the soul does not have to be is matter that you are trying to understand since it would be unable to understand it because it is it.
Aquinas would disagree with this stating that if the soul were material than it would be part of our body but we can cognize what our body is so this does not follow. He is incorrect though. Although you can understand some parts of your body there are others that you cannot since it is physically impossible for your body to do so. For example you can never see what your face looks like. What you can see is what a reflection of your face looks like by looking at a reflective substance. No matter how hard you try you can never see your entire face without a reflection since the eye is physically incapable of see it. Thus although you can cognize some aspects of your body you can never completely cognize your entire body. If you cannot cognize your entire body than it stands to reason that the soul is part of it since that which cognize something must possess none of it. So the soul since it cannot completely cognize the entire body could possibly be matter.