Aquinas Soul Problem

[YosefYosep]

So I have been lately looking up philosophical proofs for the existence and nature of the soul. Not surprisingly, my curiosity lead me to Aquinas. Now, I am trying to understand his argument about why a soul is substinent and incorporeal. I think I understand what he is saying. He mentions that if the soul (our intellect) was an operation of our body, then we would not be able to know other bodies (similar to how a hand at the temperature of water cannot sense the temperature of water). This argument does seem, however, a bit strange to me. Our intellect is a faculty of the soul, does that mean we cannot know the soul then?

*"P(1)- Q(75)- A(2) —

I answer that, It must necessarily be allowed that the principle of intellectual operation which we call the soul, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can have knowledge of all corporeal things. Now whatever knows certain things cannot have any of them in its own nature; because that which is in it naturally would impede the knowledge of anything else.

Thus we observe that a sick man’s tongue being vitiated by a feverish and bitter humor, is insensible to anything sweet, and everything seems bitter to it. Therefore, if the intellectual principle contained the nature of a body it would be unable to know all bodies. Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is likewise impossible for it to understand by means of a bodily organ; since the determinate nature of that organ would impede knowledge of all bodies; as when a certain determinate color is not only in the pupil of the eye, but also in a glass vase, the liquid in the vase seems to be of that same color.

Therefore the intellectual principle which we call the mind or the intellect has an operation “per se” apart from the body. Now only that which subsists can have an operation “per se.” For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent."*

 

[YosefYosep]

I could rephrase it like this; I am having trouble understanding the verses in bold below.

"P(1)- Q(75)- A(2) —

I answer that, It must necessarily be allowed that the principle of intellectual operation which we call the soul, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can have knowledge of all corporeal things. Now whatever knows certain things cannot have any of them in its own nature; because that which is in it naturally would impede the knowledge of anything else.

Thus we observe that a sick man’s tongue being vitiated by a feverish and bitter humor, is insensible to anything sweet, and everything seems bitter to it. Therefore, if the intellectual principle contained the nature of a body it would be unable to know all bodies. Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is likewise impossible for it to understand by means of a bodily organ; since the determinate nature of that organ would impede knowledge of all bodies; as when a certain determinate color is not only in the pupil of the eye, but also in a glass vase, the liquid in the vase seems to be of that same color.

Therefore the intellectual principle which we call the mind or the intellect has an operation “per se” apart from the body. Now only that which subsists can have an operation “per se.” For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent."

 

[Linusthe2nd]

So I have been lately looking up philosophical proofs for the existence and nature of the soul. Not surprisingly, my curiosity lead me to Aquinas. Now, I am trying to understand his argument about why a soul is substinent and incorporeal. I think I understand what he is saying. He mentions that if the soul (our intellect) was an operation of our body, then we would not be able to know other bodies (similar to how a hand at the temperature of water cannot sense the temperature of water). This argument does seem, however, a bit strange to me. Our intellect is a faculty of the soul, does that mean we cannot know the soul then?

*"P(1)- Q(75)- A(2) —

I answer that, It must necessarily be allowed that the principle of intellectual operation which we call the soul, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can have knowledge of all corporeal things. Now whatever knows certain things cannot have any of them in its own nature; because that which is in it naturally would impede the knowledge of anything else.

Thus we observe that a sick man’s tongue being vitiated by a feverish and bitter humor, is insensible to anything sweet, and everything seems bitter to it. Therefore, if the intellectual principle contained the nature of a body it would be unable to know all bodies. Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is likewise impossible for it to understand by means of a bodily organ; since the determinate nature of that organ would impede knowledge of all bodies; as when a certain determinate color is not only in the pupil of the eye, but also in a glass vase, the liquid in the vase seems to be of that same color.

Therefore the intellectual principle which we call the mind or the intellect has an operation “per se” apart from the body. Now only that which subsists can have an operation “per se.” For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent."*

By body Thomas, following Aristotle, means any thing that has a physical deminsion; a material thing. Now if man’s intellect were a physical thing, how could it know anything, even itself. A block of wood has no self awareness and it doesn’t know anything else. It is true that I know things by the use of my brain, which is a physical body. But if that were all there was to human nature, I would not know myself, nor would I know anything else, I wouldn’t know anything, because I would be merely a mass of chemicals, atoms, molecules, etc. But the fact that I do know myself, and that I know other things, and that I can think and remember means that I am not merely a mass of chemicals, etc. There is an immaterial something in me that transcends all the physical stuff of my brain and knows and thinks and remembers. It is the human soul. Yet it does use the brain in its operations.

Another proof that we have a spiritual soul is that even though every cell of my brain is replaced every few years, I still know that I am the same person I was as when I was 2 or 3 years old, and I can still remember many things from those years even though I may be 80 or 90 years old and I can still remember what I thought about many things from those years and later years.

And since the intellect is an immaterial principle, it has no matter which will decompose, it will live forever, even after being separated from the body. It is only material things which cease to exist.

What I have said here is what Thomas said, but in less complex language. Once you really understand the definitions Thomas gives for the terms he uses, his explanation is crystal clear, but you have to understand the terms first. And that takes some getting used to because he is very technical and precise in his language.

Pax
Linus2nd

 

[GEddie]

We cannot know the human soul, or the mind, directly..

(In fact, I have participated in debates on this very system where the existence of a human mind, as distinct from the brain or head, was categorically denied.)

We can however infer the existence of the mind/soul by how we are made.

ICXC NIKA.

 

[GEddie]

Although being a nonThomist and a nonphilosopher, I will take a crack at your question.

“Knowing” would seem to be not a property of solid bodies, and so this would include our human soma.

Solid bodies have certain propensities, which may include movement and aliveness, but to Thomas, at least, knowing requires a spiritual functionality.

ICXC NIKA.

 

[lmelahn]

So I have been lately looking up philosophical proofs for the existence and nature of the soul. Not surprisingly, my curiosity lead me to Aquinas. Now, I am trying to understand his argument about why a soul is substinent and incorporeal. I think I understand what he is saying. He mentions that if the soul (our intellect) was an operation of our body, then we would not be able to know other bodies (similar to how a hand at the temperature of water cannot sense the temperature of water). This argument does seem, however, a bit strange to me. Our intellect is a faculty of the soul, does that mean we cannot know the soul then?

Not exactly. His point is that a material power (such as the sense of touch) cannot perceive itself as it senses. The eye cannot see itself seeing. On the other hand, the intellect, which is a spiritual power, is aware of itself (or better said, the soul, through its intellect, is aware of itself).

The idea is that only a simple and immaterial substance could be self-aware like that.