More on Descartes: His Second "Proof"
My third ever entry on this blog had to do (in part) with René Descartes and his famous Cogito, ergo sum.[1] I have referred back to that entry many times in discussions here about epistemology, how my belief in my own existence is (after believing in logic) the second most secure of all my beliefs.[2]
While I highly respect Descartes - he's the first real philosopher I ever read - and, in theory, love his stated method of searching for truth by means of the "clear and distinct", beyond his initial cogito, I do not think he very successfully proved much of anything else.
I've returned to Descartes again recently, because I have been off-and-on attending a philosophy discussion group started by one of my best friends from college, J.M. The group has been meeting for about ten years now, but I did not join in until a few months ago when they entered the era of modern philosophy, which Descartes had a major role in ushering in. Thus, I have reread Descartes and been introduced to the works of Baruch/Benedict de Spinoza and, most recently, Nicolas Malebranche.
Last night, at the meeting, there was some discussion about the "dualism problem" created by Descartes and how much of a departure it was from previous ideas of a union of body and soul.[3]
What is this "dualism problem"? Well, as discussed here before,[1] the first thing Descartes proved to himself with his philosophical method was that he existed. The second thing he proved to himself was that his identity was separate from his body and did not require it to exist. In other words, he thought, therefore, he was, yet what he was was a "thinking substance" or "soul" - not a body.
In his own words, from a translation of his Discourse on the Method of Rightly Conducting the Reason:In the next place, I attentively examined what I was, and... I observed that I could suppose that I had no body but that... I could not... suppose that I was not.... While, on the other hand, if I had only ceased to think, although all the other objects that I had ever imagined had been in reality existent, I would have had no reason to believe that I existed. I thence concluded that I was a substance whose whole essence or nature consists only in thinking and that... has need of no place nor is dependent on any material thing; so that "I" (that is to say, the mind by which I am what I am) is wholly distinct from the body and is even more easily known than the latter and is such that, although the latter were not, it would still continue to be all that it is.
This is how Descartes came to the idea of separate substances of mind and body. Malebranche, strongly influenced by Descartes, used a different proof to arrive at the same conclusion (in his first of the Dialogues on Metaphysics):Now, I think; so I am.... But what am I - the "I" that thinks whenever I'm thinking? Am I a body, a mind, a man?... Well, can a body think? Is a thing that has length, breadth, and depth capable of reasoning, desiring, sensing? Certainly not! For the only states that such an extended thing can have consist in spatial relations; and, obviously, those are not perceptions, reasonings, pleasures, desires, sensations - in a word, thoughts. Since my perceptions are something entirely different from spatial relations and since they are certainly mine, it follows that this "I" that thinks, my very substance, is not a body.
This is dualism, but what is the problem? The problem is that Descartes could give no reasonable explanation for how the substance of his mind/soul could have any effect on the substance of his body or vice versa. (He even resorted to some crazy idea about a pineal gland in the brain being blown about by whispers from the soul to control the body.)
Ever since Descartes created this problem (although some have shown that it is an idea present even in infants[4]), other philosophers after him have sought to solve it. Descartes' own solution, as I mentioned, was an interaction between the two substances mediated by the pineal gland in the brain.
Malebranche's solution is termed "occasionalism". For Malebranche, there are two substances (as you read him explain above); however, they have no interaction. It just happens to be the case that God occasions it that, whenever we choose to do something with our body in our mind, our body then responds in such a way that it appears as if our mind had caused that action.
But is there really a "problem" at all? Only if you accept one of the "proofs" that mind and body are separate and independent substances. Spinoza solved the problem by denying the premise. His solution is termed "neutral monism". For Spinoza, there is only one substance in the universe at all; mind and body are simply different ways of looking at the same thing.
I do not agree with Spinoza's limitation to only one substance in the whole universe, but I find both Descartes' and Malebranche's proofs of dualism lacking. Descartes argued that, because it was possible for him to imagine himself without a body, this proved that his mind had "need of no place nor [was] dependent on any material thing." But this is not a logical argument. Let's use my favorite software/hardware analogy[5] once again. I can easily enough imagine a computer program without a computer, but said program needs a material computer and depends on it for it to have any meaningful function or existence.
Likewise, Malebranche's alternative argument I find unconvincing. Malebranche rhetorically asks, "Is a thing that has length, breadth, and depth capable of reasoning, desiring, sensing? Certainly not!" But this is not a proof; it's essentially saying, I cannot think of a way to explain how one can arrive at "perceptions, reasonings, pleasures, desires, sensations" from spatial relations, therefore, it cannot happen. This, if I understand the term correctly, is an argument ad ignorantium. In the lease, it is confusing something unexplained with something unexplainable.
While I highly respect Descartes - he's the first real philosopher I ever read - and, in theory, love his stated method of searching for truth by means of the "clear and distinct", beyond his initial cogito, I do not think he very successfully proved much of anything else.
I've returned to Descartes again recently, because I have been off-and-on attending a philosophy discussion group started by one of my best friends from college, J.M. The group has been meeting for about ten years now, but I did not join in until a few months ago when they entered the era of modern philosophy, which Descartes had a major role in ushering in. Thus, I have reread Descartes and been introduced to the works of Baruch/Benedict de Spinoza and, most recently, Nicolas Malebranche.
Last night, at the meeting, there was some discussion about the "dualism problem" created by Descartes and how much of a departure it was from previous ideas of a union of body and soul.[3]
What is this "dualism problem"? Well, as discussed here before,[1] the first thing Descartes proved to himself with his philosophical method was that he existed. The second thing he proved to himself was that his identity was separate from his body and did not require it to exist. In other words, he thought, therefore, he was, yet what he was was a "thinking substance" or "soul" - not a body.
In his own words, from a translation of his Discourse on the Method of Rightly Conducting the Reason:In the next place, I attentively examined what I was, and... I observed that I could suppose that I had no body but that... I could not... suppose that I was not.... While, on the other hand, if I had only ceased to think, although all the other objects that I had ever imagined had been in reality existent, I would have had no reason to believe that I existed. I thence concluded that I was a substance whose whole essence or nature consists only in thinking and that... has need of no place nor is dependent on any material thing; so that "I" (that is to say, the mind by which I am what I am) is wholly distinct from the body and is even more easily known than the latter and is such that, although the latter were not, it would still continue to be all that it is.
This is how Descartes came to the idea of separate substances of mind and body. Malebranche, strongly influenced by Descartes, used a different proof to arrive at the same conclusion (in his first of the Dialogues on Metaphysics):Now, I think; so I am.... But what am I - the "I" that thinks whenever I'm thinking? Am I a body, a mind, a man?... Well, can a body think? Is a thing that has length, breadth, and depth capable of reasoning, desiring, sensing? Certainly not! For the only states that such an extended thing can have consist in spatial relations; and, obviously, those are not perceptions, reasonings, pleasures, desires, sensations - in a word, thoughts. Since my perceptions are something entirely different from spatial relations and since they are certainly mine, it follows that this "I" that thinks, my very substance, is not a body.
This is dualism, but what is the problem? The problem is that Descartes could give no reasonable explanation for how the substance of his mind/soul could have any effect on the substance of his body or vice versa. (He even resorted to some crazy idea about a pineal gland in the brain being blown about by whispers from the soul to control the body.)
Ever since Descartes created this problem (although some have shown that it is an idea present even in infants[4]), other philosophers after him have sought to solve it. Descartes' own solution, as I mentioned, was an interaction between the two substances mediated by the pineal gland in the brain.
Malebranche's solution is termed "occasionalism". For Malebranche, there are two substances (as you read him explain above); however, they have no interaction. It just happens to be the case that God occasions it that, whenever we choose to do something with our body in our mind, our body then responds in such a way that it appears as if our mind had caused that action.
But is there really a "problem" at all? Only if you accept one of the "proofs" that mind and body are separate and independent substances. Spinoza solved the problem by denying the premise. His solution is termed "neutral monism". For Spinoza, there is only one substance in the universe at all; mind and body are simply different ways of looking at the same thing.
I do not agree with Spinoza's limitation to only one substance in the whole universe, but I find both Descartes' and Malebranche's proofs of dualism lacking. Descartes argued that, because it was possible for him to imagine himself without a body, this proved that his mind had "need of no place nor [was] dependent on any material thing." But this is not a logical argument. Let's use my favorite software/hardware analogy[5] once again. I can easily enough imagine a computer program without a computer, but said program needs a material computer and depends on it for it to have any meaningful function or existence.
Likewise, Malebranche's alternative argument I find unconvincing. Malebranche rhetorically asks, "Is a thing that has length, breadth, and depth capable of reasoning, desiring, sensing? Certainly not!" But this is not a proof; it's essentially saying, I cannot think of a way to explain how one can arrive at "perceptions, reasonings, pleasures, desires, sensations" from spatial relations, therefore, it cannot happen. This, if I understand the term correctly, is an argument ad ignorantium. In the lease, it is confusing something unexplained with something unexplainable.