Hylomorphism vs. Cartesian Dualism: Exploring the Mind and Body with Thomas Aquinas

           

         Hylomorphism, a theory proposed by Aristotle and appropriated into Christian philosophy by Thomas Aquinas, entails that entities, including the mind and body, are a combination of matter (hyle) and form (morphe). Dualism, in contrast to monism, posits a fundamental distinction between mind and body as separate substances. Aristotle’s hylomorphism, on the other hand, emphasizes the unity of form and matter in entities, proposing an interconnected relationship rather than strict separation. So, I began to ponder the differences between Aristotle’s hylomorphism and Cartesian dualism. Cartesian dualism, proposed by René Descartes, posits a strict separation between the mind (res cogitans) and the body (res extensa). Descartes viewed the mind as non-material and distinct from the material body, suggesting that they interacted through the pineal gland. So, while hylomorphism emphasizes unity, Cartesian dualism emphasizes a clear distinction between mind and body. One can separate the soul and body with Descartes but the matter and form cannot be separate for Aristotle.

But where does Aquinas fall into this as he indeed drew heavily from Aristotelian metaphysics but then how does he view heaven? Does the soul have its own spiritual form in the afterlife or does it still possess a material body? For Aquinas, anything that is alive has a soul, although we are identical with our bodies, they are ensouled in their very nature because we have an intellect and a will. Therefore, we have both a body and a soul, but are not composed of a body and a soul. The soul is just that thing which animates our bodies and distinguishes us from material objects that are not alive such as a rock. Yet, it is not some separate independently existing thing that merely interacts with our bodies. It is something that subsists in and is co-extensive with our bodies. Using Aristotelian terms, the soul is the form of the body. To use clay as an analogy, matter is the clay itself while the form is the shape that the clay takes on, for example, the shape of a pot. Similarly, my soul is what dictates that the matter my body is made of is a human body and delineates all of its properties and functions. It is not a separate substance that is distinct from my body. As long as I have a human body, I necessarily have a human soul as it is essential to have a body in order to be a human, according to Aquinas. Fundamental to Aquinas’s hylomorphism is his coordinate distinction between potentiality and actuality. Matter is to form as potentiality is to actuality.

While many Christian thinkers hold that we maintain our identity after our physical deaths because we survive as souls, Aquinas thinks that while our souls survive physical death, we actually do not! For Aquinas, something dies when it loses its substantial form. But if you think about it, souls can be described as a substantial form, and substantial forms are immaterial objects that cannot lose themselves. Therefore, it is possible that God can supernaturally sustain our souls after we physically die. However, because we are not identical to our souls and only exist as us while we have a body, we technically will not exist in the intermediate state; only our souls will unless I am misunderstanding Aquinas. The soul’s incorruptibility entails that, after death, it will continue to exist without the body but it is uncertain if that is the same “us”. Aquinas thinks a person’s soul, surviving apart from its body, is not sufficient for that person’s survival so perhaps in heaven it will be different as perhaps the active intellect of the soul is not dependent upon the body and will be sustained by God. 

I personally hold to substance dualism. Aquinas wants to say that the soul is not the whole person but if he wants to hold that the soul can exist without the body then I do not see a way out of identifying the soul with the individual as is the case with substance dualism. For Aristotle, a rock cannot exist without the form of a rock as there are no uninstantiated forms so for Aquinas to hold this view of hylomorphism he would have to accept that the soul cannot exist without the body. The soul, in my view, contains the properties of individuation.