Introduction and Context:
In describing what philosophy does, I've heard Prof. Todd Jones (of UNLV) say "philosophy is usually about one of two things: Things that are so abstract and obscure that most people wouldn't bother to think about them, and things that are so obvious that most people wouldn't bother to think about them." Substance dualism falls into the latter category. For most people, that humans have an immaterial mind/soul that is independent from their body is so obvious, it's not even something to question...but this is a philosophy class!
Up until now we've looked at what substance dualism is, how Descartes argued for it, and one of it's main problems--the interaction problem. Now we're going to look at another argument against substance dualism: the communication problem (aka argument from brain damage). The communication problem is that substance dualism gives a very poor account of why brain damage (i.e., damage to a physical system) has an effect on the mind (i.e., an independent non-physical system). That is, if the brain and the mind are two distinct entities, and the immaterial mind can exist intact and fully functional for eternity without a body (i.e., brain), why should brain damage matter to mental abilities now--when we have a brain?
Essentially, the argument is that the physicalist model give a comparatively better account: it says certain parts of the brain are responsible for certain functions. If you damage those parts, you'll diminish or lose those functions.
Brain Damage: The Case of Clive Wearing
The communication problem becomes apparent when we consider how substance dualism would account for loss of mental capacities caused by brain damage.
Consider the famous case of Clive Wearing (CW) who, after having a normal life for 50 years, contracted viral encephalitis. The end result of the encephalitis was anterograde and fairly severe retrograde amnesia. The former is when you can no longer form new memories, the latter is when one cannot recall events from before the brain damage occurred. Brain scans on CW showed that the areas associated with memory had, for the most part, been destroyed by the virus.
It's a Communication Problem: The Dualist Account of Brain Damage
The dualist account of brain damage cannot imply that damage to the brain would cause damage to the mind. Since the mind isn't the brain and the mind can persist eternally regardless of whether we have a physical brain or not, they have to explain why brain damage apparently causes loss or diminishment of mental functions. I emphasize "apparent" because the dualist cannot answer that damage to the mind can actually occur as a consequence of damage to the brain. Otherwise, how do you explain how the soul function and exist eternally once the brain is worm food? For this reason, the dualist instead has to argue that the mental damage is only apparent.
The dualist has to argue that the mind remains perfectly intact but something's gone wrong with the mind-brain interface. We can think of it like this: the brain has within it a "modem" or "router" that transmits stuff about the body to the mind and also receives information from the mind (to be converted into physical movements). In the case of brain damage, what has gone wrong is not that the mind doesn't function perfectly (it still does), it's that the modem/router isn't working for certain types of operations. In short, for the dualist, brain damage is a communication problem between a damaged physical system and an undamaged non-physical system.
Two Possible Dualist Replies
There are two possible dualist accounts of why the communication between mind and body fail. The first is that the perfectly intact mind sends information to the brain, but upon receiving the information, the brain messes it up somehow. The second is that the brain, because it's broken, sends the mind distorted information and so that's why new memories can't be formed. Lets flesh these out...
Option 1: Distorted Input
Think back to CW with his anterograde and retrograde amnesia: When he is asked if he remembers his wedding, he replies he doesn't. The dualist has to say that this memory is perfectly preserved in his undamaged immaterial mind. When someone asks him, "How was your wedding?" in his immaterial mind he perceives it perfectly but the receiver in the brain somehow mistranslates his intended answer (the description of the memory) to "I don't remember." The receiver in the brain takes the mind's input of clear coherent memories and garbles it, thereby causing the output "I don't remember."
On this account, poor CW has total access to the memories. They are as vivid and clear to him as they were pre-brain damage. He just can't express them to people.
This, on it's own, seems quite implausible but it gets worse. CW's retrograde amnesia doesn't apply to all his memories, it's not complete. If you ask him if he is married, he will say "yes." Why is it that for some memories the "modem" garbles the input from the mind and in other cases it doesn't? Does each memory have a separate modem? That doesn't seem very plausible...
The other difficulty is to explain why, when the modem garbles the mind's input, is the output always "I don't know"? Why not "gjkdajfopjoqwjfoa[jfo[asj[fj'ljkd!" or "I like ice cream"? And why does it garble in these ways for memories about the wedding but not for memories about whether he's married?
Although the physicalist model is still a work in progress, its account (brain equals the mind, damage to brain equals damage to mind) seems much more plausible and in line with our best current scientific knowledge.
Option 2: Distorted Output
The other possible response the dualist can give to explain why damage to the brain is only apparent (but not real) damage to the immaterial mind is to say the communication problem is from the brain to the mind.
In the case of anterograde amnesia, the brain is trying to send new memories to the mind for storage, but the modem is down, and so they never arrive. Kind of like if you tried to upload something to the cloud but your modem is down. The information can't get to where it needs to go to get stored and so it is never encoded. So far this sounds plausible...except 2 things.
The first problem is that it seems to presume new memory formation requires having a physical brain. The dualist, in essence is saying, he can't form new memories because the part of the brain that sends experiences to the mind isn't working. The implicit assumption here is that memory formation requires having a brain! This is something the dualist cannot abide. On the other hand, if your mind can form new memories without a material brain, then why is the brain damage a problem in the first place?
If the immaterial mind can't acquire new memories except through the intermediary of the physical brain, how's this going to play out in the "ever after." Will you never be able to form any new memories once your body has decayed? Are you stuck for all eternity with only the memories you acquired in your brief stint on earth? Eternity is a long time. That might suck for more than a few people. It's certainly motivation to do some crazy shit in your life. Maybe Drake should have said "YOFMO": You Only Form Memories Once...
The second problem is this: Suppose we ask CW, "do you remember your wedding?" The sound waves enter his auditory system and get converted into a neural signal which gets sent to the brain. But since the modem that sends signals from his brain to his immaterial mind isn't working right, the message "do you remember your wedding" comes out as gibberish. The mind never receives the right question even though it contains the information to answer the question.
Up to this point, it's still a moderately plausible account. However, if the mind is receiving gibberish, why does CW respond "I don't remember" rather than "I don't understand a damn word you're saying!"
Understanding the question doesn't seem to be the real problem. That signal is getting through just fine: he just doesn't know the answer to it because he doesn't have that information.
Additional Arguments Against Dualism
Argument from Phylogenesis
At what point in the evolutionary process the organisms get "souls"? Most people (except maybe Leibniz) would say that one celled organisms don't have souls. So how about 2 celled organisms? No? What about 3? ...4? 100?
Recall that for the dualist you can't have partial souls, so the dualist can't say that mental capacities gradually evolved along with complexity. Either you have a complete functioning soul or you don't. This means that at a certain point in evolutionary development a parent didn't have a soul while the offspring did. The metaphysical commitment to the existence of metaphysically independent immaterial souls makes the existence of souls difficult to square with our best scientific knowledge of the development of life.
Argument from Ontogenesis
The argument from ontogenesis is similar to the previous argument but applies at the level of the individual organism. Consider how an individual human develops. Most people, including dualists, will say that neither the sperm or the egg has a soul. When the two touch to form a single cell, does a soul appear too? If so from where? How do we know? Does a single cell have a soul? If not, then how about when that cell divides and becomes 2 cells. Now does it have a soul? What about after there are 4 cells?
The idea that "poof" a soul appears after a certain number of cell divisions is going to be difficult to defend. It's just as problematic as defending the idea that a soul appears for a single cell the moment the sperm penetrates the egg.
To a certain extent, defending against the arguments from phylogenesis and ontogenesis require to dualist to make empirically defensible claims about when the soul appears. This will be tough.
Showing posts with label Dualism. Show all posts
Showing posts with label Dualism. Show all posts
Thursday, September 19, 2013
Tuesday, September 17, 2013
How Can Souls Move Bodies? Descartes and Princess Elisabeth of Bohemia
Introduction and Context:
In the previous post we got a quick introduction to substance dualism (aka Cartesian dualism), the idea that the mind/soul and the body are not one and the same and are therefore fundamentally distinct substances. That is, your brain is not your mind and your mind is not your brain. We looked at two of the arguments that Descartes gave for the position and some of the objections. Whether we find the arguments convincing or not, most psychological studies show that most people are dualists (but few philosophers and neurologists are). There are also some contemporary arguments for different types of dualism which we'll look at in later posts but for now we're going to focus on substance dualism.
Setting all that aside, supposing we are convinced that dualism is true, it's interesting to consider what difficulties this position might give rise to. Descartes' contemporary, Princess Elizabeth of Bohemia (who's momma didn't raise no fool) brought up some of these problems to Descartes himself in their written correspondence.
The Interaction Problem
At the heart of the problem with dualism is the interaction problem: how is it that something that doesn't have any physical properties (i.e., doesn't exist in space, has no extension, and has no mass) can interact causally with something that is physically extended and has mass? and vice versa...
So, how is it that thoughts in the mind (which have absolutely no physical properties) can causally bring about actions in a physical body? Or that something happening to the body (e.g., stimulation of our perceptual organs or being poked by a needle) can bring about perceptual experiences and thoughts (e.g., "I see a red chair" or "ouch! that freakin' hurt!") It would seem that for anything to causally affect a physical body it too must be physical or at least have some minimal physical properties like mass and extension (unless you want to invoke magic).
To see how Descartes responds to the interaction problem, Let's take a look at the back and forth in the letters between the two and see if he gives a satisfactory response.
May 21, 1643: Descartes' First Attempt
The reason it seems like there's an interaction problem between mind and body is because I haven't explained how they interact yet! The goal of the Meditations was only to give the notions of body and soul that explained why they are 2 distinct substances--not to explain how they interact. But now that you're asking...
Also, although I only discussed the notions of body and mind that allow us to distinguish them, it doesn't mean that there aren't additional notions we can appeal to that explain how the two interact.
The confusion arises because you are using the notions that allow us to distinguish between the two to try to explain how the two interact. But this obviously won't work because we're missing the relevant explanatory notions!
He then gives Elizabeth an analogy to illustrate his point:
The scholastics (the tradition of philosophy that Descartes opposed) believed that there was a "thing" called "heaviness" that caused objects to fall to the ground. But they were misunderstanding the notion of heaviness. Yes, having "heaviness" is why objects fall to the earth, but the scholastics misunderstand "heaviness" as being an actual thing that physically causes the object to fall. They were misapplying concepts, this is why they were confused.
Something along the same lines is happening when we talk about the properties we attribute to our bodies and minds to account for how they interact. We are mis-conceptualizing and misusing the properties, and this is the cause of our confusion.
To summarize, (1) He sort of explains why, given the incomplete descriptions of mind and body that he's given, we can't understand how mind and body interact. However, (2) he avoids ever giving an answer to the interaction problem.
June 10, 1643: Elizabeth's Reply
Before I begin, I just want to point out that Elisabeth's writing is a stunning example of the principle of charity. Descartes' initial reply was unconvincing at best and totally side-steps the problem at worst. But look how Elizabeth replies
Now the interests of my house, which I must not neglect, now some conversations and social obligations which I cannot avoid, beat down so heavily on this weak mind with annoyance or boredom, that it is rendered useless for anything else at all for a long time afterward: this will serve, I hope, as an excuse for my stupidity in being unable to comprehend [the "heaviness" example that Descartes gives to explain why the interaction problem isn't really a problem, but simply the result of not having or misunderstanding the notions for explaining how interaction occurs].
Ah! If only facebook and youtube disputes had this much civility....(meh...they wouldn't nearly be as much fun).
Ok, on to her reply...
In short she says, even with the "heaviness" example, I still don't understand how an immaterial thing that doesn't exist in space or have mass or extension can causally interact (via contact) with a physical thing (i.e., the body). I cannot conceive of an immaterial thing as anything but the negation of matter, and in order for matter to move, it must be acted upon by physical force and contact (none of which are possible for an immaterial substance to do).
In fact, it would be easier for me to think of the soul as being material than to conceive of how something non-material could causally interact with something material.
(Bonus information: Locke, writing just after Descartes, actually suggests this as a solution: If God can do anything, why could he not create matter that can think?)
Information?
Always the helpful one, Elisabeth offers Descartes a possible solution: One possibility would be that the soul moves the body by communicating information to it, however, the information can only be interpreted and understood by the body if the body possesses intelligence...and Descartes denies that matter can be intelligent..Doh! So, that's not going to work...
June 28, 1643: Descartes Second Reply
In short, Descartes still doesn't offer a direct answer. He says that since it is easier for her Highness "to attribute matter and extension to the soul than to attribute to it the capacity to move a body and to be moved by one without having matter" she should feel free to attribute the matter and extension to the soul. By doing so she will be able to conceive of the union of soul and body, even though in reality they are two distinct things.
This reply is quite unsatisfactory because (a) if the soul is not extended (as Descartes maintains) how will conceiving it as such explain away the interaction problem? Also, (b) if we are to conceive of the union of body and soul as Descartes instructs us, presumably this would involve conceiving of some sort of causal connection, but that's precisely the thing that Elizabeth is not able to conceive of!
Clearly irritated by the fact that he can't come up with a good answer, Descartes ends his letter by admonishing Elizabeth for being too philosophical!
Finally, though I believe it is very necessary to have understood well once in one's life the principles of metaphysics, since it is these that give us knowledge of God and of our soul, I also believe that it would be very harmful to occupy one's understanding often in meditating on them [...]
Lol.
Now, we're getting into facebook-fight territory! At this point I think Descartes would have blocked her...
Sept. 13, 1645: Elisabeth's Reply
Up until now, Elisabeth was primarily focused on asking how the immaterial mind could causally influence the actions of the material body. Now, she asks for clarification on the other side of the interaction problem: How is it that the "passions" (i.e., bodily feelings like hunger or physical pleasure) can interact with the non-material mind to influence our thoughts?
The Passions of the Soul (Not of particular philosophical import)
Descartes wrote The Passions of the Soul largely as a response to Elisabeth's request for more information on the interaction between the passions and the immaterial mind.
First he lays the groundwork for how to distinguish between things that pertain to the soul and things that pertain to the body:
(1) Anything that we can experience as being in us and which we see as existing in wholly inanimate bodies must be attributed to our body;
(2) Anything that we cannot conceive of as belonging to a body must belong to the soul.
From (2) it follows that thoughts belong to the soul. From (1) it follows that heat and movement belong to the body.
17C Physiology and Anatomy 101: How the animal spirits (the stuff that causes bodies to move) cause movement:
The animal spirits (tiny particles that 17C physicians believe to be responsible for animation) are contained in the blood. They are very very fine particles. The heart pumps them up to the brain where they enter cavities and go through pores thereby coming in contact with the nerves and then the muscles. That's how bodies moves...(!)
How does the body move without the soul?
Sometimes the animal spirits can cause some pores to open or close more than others, which in turn causes a muscle to contract more or less. The sensory nerves can cause the pores to be opened more or less than usual, which in turn causes the animal spirits to change direction and go to the muscles in such a way that causes the body part to move as it usually does for such an occasion.
In short, our bodies are self-sufficient robots. Our sensors cause the animal spirits to open and close pores which in turn direct the animal spirits to the correct muscles for the appropriate movements.
The function of the soul: In this mechanistic framework you may be asking where our soul/mind is in all this. The soul is the "place" where we have our thoughts of which there are 2 main kinds: actions of the soul and passions of the soul. Actions of the soul are our volitions since we experience them as coming from our soul. The passions of our soul are the various perceptions we have since they are externally caused.
How do the soul and body interact? Through the pineal gland in the brain.
How do we know the pineal gland is the "seat of the soul"? All of the organs for our external senses come in twos (eyes, hands, ears, and so on...) (Ignore that you only have one tongue and one mouth, 10 fingers, etc..!) There must be a place where the two images coming in the two eyes or the double organs of any other sense converge to form a single image or impression before reaching the soul--otherwise the soul would see two of the image! That's science! ...well, 17C science anyway...
(Sadly, there are people who still believe this!!!)
In the previous post we got a quick introduction to substance dualism (aka Cartesian dualism), the idea that the mind/soul and the body are not one and the same and are therefore fundamentally distinct substances. That is, your brain is not your mind and your mind is not your brain. We looked at two of the arguments that Descartes gave for the position and some of the objections. Whether we find the arguments convincing or not, most psychological studies show that most people are dualists (but few philosophers and neurologists are). There are also some contemporary arguments for different types of dualism which we'll look at in later posts but for now we're going to focus on substance dualism.
Setting all that aside, supposing we are convinced that dualism is true, it's interesting to consider what difficulties this position might give rise to. Descartes' contemporary, Princess Elizabeth of Bohemia (who's momma didn't raise no fool) brought up some of these problems to Descartes himself in their written correspondence.
The Interaction Problem
At the heart of the problem with dualism is the interaction problem: how is it that something that doesn't have any physical properties (i.e., doesn't exist in space, has no extension, and has no mass) can interact causally with something that is physically extended and has mass? and vice versa...
So, how is it that thoughts in the mind (which have absolutely no physical properties) can causally bring about actions in a physical body? Or that something happening to the body (e.g., stimulation of our perceptual organs or being poked by a needle) can bring about perceptual experiences and thoughts (e.g., "I see a red chair" or "ouch! that freakin' hurt!") It would seem that for anything to causally affect a physical body it too must be physical or at least have some minimal physical properties like mass and extension (unless you want to invoke magic).
To see how Descartes responds to the interaction problem, Let's take a look at the back and forth in the letters between the two and see if he gives a satisfactory response.
May 21, 1643: Descartes' First Attempt
The reason it seems like there's an interaction problem between mind and body is because I haven't explained how they interact yet! The goal of the Meditations was only to give the notions of body and soul that explained why they are 2 distinct substances--not to explain how they interact. But now that you're asking...
Also, although I only discussed the notions of body and mind that allow us to distinguish them, it doesn't mean that there aren't additional notions we can appeal to that explain how the two interact.
The confusion arises because you are using the notions that allow us to distinguish between the two to try to explain how the two interact. But this obviously won't work because we're missing the relevant explanatory notions!
He then gives Elizabeth an analogy to illustrate his point:
The scholastics (the tradition of philosophy that Descartes opposed) believed that there was a "thing" called "heaviness" that caused objects to fall to the ground. But they were misunderstanding the notion of heaviness. Yes, having "heaviness" is why objects fall to the earth, but the scholastics misunderstand "heaviness" as being an actual thing that physically causes the object to fall. They were misapplying concepts, this is why they were confused.
Something along the same lines is happening when we talk about the properties we attribute to our bodies and minds to account for how they interact. We are mis-conceptualizing and misusing the properties, and this is the cause of our confusion.
To summarize, (1) He sort of explains why, given the incomplete descriptions of mind and body that he's given, we can't understand how mind and body interact. However, (2) he avoids ever giving an answer to the interaction problem.
June 10, 1643: Elizabeth's Reply
Before I begin, I just want to point out that Elisabeth's writing is a stunning example of the principle of charity. Descartes' initial reply was unconvincing at best and totally side-steps the problem at worst. But look how Elizabeth replies
Now the interests of my house, which I must not neglect, now some conversations and social obligations which I cannot avoid, beat down so heavily on this weak mind with annoyance or boredom, that it is rendered useless for anything else at all for a long time afterward: this will serve, I hope, as an excuse for my stupidity in being unable to comprehend [the "heaviness" example that Descartes gives to explain why the interaction problem isn't really a problem, but simply the result of not having or misunderstanding the notions for explaining how interaction occurs].
Ah! If only facebook and youtube disputes had this much civility....(meh...they wouldn't nearly be as much fun).
Ok, on to her reply...
In short she says, even with the "heaviness" example, I still don't understand how an immaterial thing that doesn't exist in space or have mass or extension can causally interact (via contact) with a physical thing (i.e., the body). I cannot conceive of an immaterial thing as anything but the negation of matter, and in order for matter to move, it must be acted upon by physical force and contact (none of which are possible for an immaterial substance to do).
In fact, it would be easier for me to think of the soul as being material than to conceive of how something non-material could causally interact with something material.
(Bonus information: Locke, writing just after Descartes, actually suggests this as a solution: If God can do anything, why could he not create matter that can think?)
Information?
Always the helpful one, Elisabeth offers Descartes a possible solution: One possibility would be that the soul moves the body by communicating information to it, however, the information can only be interpreted and understood by the body if the body possesses intelligence...and Descartes denies that matter can be intelligent..Doh! So, that's not going to work...
June 28, 1643: Descartes Second Reply
In short, Descartes still doesn't offer a direct answer. He says that since it is easier for her Highness "to attribute matter and extension to the soul than to attribute to it the capacity to move a body and to be moved by one without having matter" she should feel free to attribute the matter and extension to the soul. By doing so she will be able to conceive of the union of soul and body, even though in reality they are two distinct things.
This reply is quite unsatisfactory because (a) if the soul is not extended (as Descartes maintains) how will conceiving it as such explain away the interaction problem? Also, (b) if we are to conceive of the union of body and soul as Descartes instructs us, presumably this would involve conceiving of some sort of causal connection, but that's precisely the thing that Elizabeth is not able to conceive of!
Clearly irritated by the fact that he can't come up with a good answer, Descartes ends his letter by admonishing Elizabeth for being too philosophical!
Finally, though I believe it is very necessary to have understood well once in one's life the principles of metaphysics, since it is these that give us knowledge of God and of our soul, I also believe that it would be very harmful to occupy one's understanding often in meditating on them [...]
Lol.
Now, we're getting into facebook-fight territory! At this point I think Descartes would have blocked her...
Sept. 13, 1645: Elisabeth's Reply
Up until now, Elisabeth was primarily focused on asking how the immaterial mind could causally influence the actions of the material body. Now, she asks for clarification on the other side of the interaction problem: How is it that the "passions" (i.e., bodily feelings like hunger or physical pleasure) can interact with the non-material mind to influence our thoughts?
The Passions of the Soul (Not of particular philosophical import)
Descartes wrote The Passions of the Soul largely as a response to Elisabeth's request for more information on the interaction between the passions and the immaterial mind.
First he lays the groundwork for how to distinguish between things that pertain to the soul and things that pertain to the body:
(1) Anything that we can experience as being in us and which we see as existing in wholly inanimate bodies must be attributed to our body;
(2) Anything that we cannot conceive of as belonging to a body must belong to the soul.
From (2) it follows that thoughts belong to the soul. From (1) it follows that heat and movement belong to the body.
17C Physiology and Anatomy 101: How the animal spirits (the stuff that causes bodies to move) cause movement:
The animal spirits (tiny particles that 17C physicians believe to be responsible for animation) are contained in the blood. They are very very fine particles. The heart pumps them up to the brain where they enter cavities and go through pores thereby coming in contact with the nerves and then the muscles. That's how bodies moves...(!)
How does the body move without the soul?
Sometimes the animal spirits can cause some pores to open or close more than others, which in turn causes a muscle to contract more or less. The sensory nerves can cause the pores to be opened more or less than usual, which in turn causes the animal spirits to change direction and go to the muscles in such a way that causes the body part to move as it usually does for such an occasion.
In short, our bodies are self-sufficient robots. Our sensors cause the animal spirits to open and close pores which in turn direct the animal spirits to the correct muscles for the appropriate movements.
The function of the soul: In this mechanistic framework you may be asking where our soul/mind is in all this. The soul is the "place" where we have our thoughts of which there are 2 main kinds: actions of the soul and passions of the soul. Actions of the soul are our volitions since we experience them as coming from our soul. The passions of our soul are the various perceptions we have since they are externally caused.
How do the soul and body interact? Through the pineal gland in the brain.
How do we know the pineal gland is the "seat of the soul"? All of the organs for our external senses come in twos (eyes, hands, ears, and so on...) (Ignore that you only have one tongue and one mouth, 10 fingers, etc..!) There must be a place where the two images coming in the two eyes or the double organs of any other sense converge to form a single image or impression before reaching the soul--otherwise the soul would see two of the image! That's science! ...well, 17C science anyway...
(Sadly, there are people who still believe this!!!)
Monday, September 16, 2013
Descartes and Philosophy of Mind: The Conceivability Argument and the Divisibility Argument
Introduction and Context:
Watch the Video first:
Poor Karl. Lets try to help him clear up his confusion. Fortunately, we have philosophy at our disposal to provide some answers in our time of need (where else could you possibly go?). To get at some kind of an answer lets start with Descartes who thought he had a solution to this problem. The short answer, as you should know by now, is that you are a mind, not a body.
Descartes proposed 3 main arguments for what is called substance dualism which is the position that the mind and the body (i.e., brain) are two completely different types of things (i.e, substances). Because my main goal is simply to present the general position, for our purposes we'll only look at two of the arguments.
Ok, with those principles in "mind" lets take a look at a stripped down version of the argument:
(P1) I conceive that I, a thinking thing, can exist without my extended (i.e., physical) body existing.
Recall from the 1st meditation where Descartes shows that we can doubt everything, including the existence of our own physical body, except that we think and that we exist. Because we can conceive of ourselves as existing without having a body, we must not be identical to our body. Since we are not identical to our body, our minds and our bodies must be 2 completely different sorts of things (he calls them "substances").
(P1) All extended things are divisible. (It's possible to divide the body or matter into parts)
Watch the Video first:
So, is the brain the mind? Is the mind the brain? Are they separate things? If so, are you your brain or your mind? Or are you somehow both but they aren't the same thing? Are you confused?
Poor Karl. Lets try to help him clear up his confusion. Fortunately, we have philosophy at our disposal to provide some answers in our time of need (where else could you possibly go?). To get at some kind of an answer lets start with Descartes who thought he had a solution to this problem. The short answer, as you should know by now, is that you are a mind, not a body.
Descartes proposed 3 main arguments for what is called substance dualism which is the position that the mind and the body (i.e., brain) are two completely different types of things (i.e, substances). Because my main goal is simply to present the general position, for our purposes we'll only look at two of the arguments.
The Conceivability Argument (6th Meditation)
The conceivability argument rests upon two similar principles: (a) The doctrine of clear and distinct is that anything that can be clearly and distinctly conceived of is possible and therefore can, in the "real world" correspond perfectly with one's understanding of it. Lets not worry too much about this part...The other principle plays a more important role: Hume's law is that if we can conceive of something then it is logically possible.
(P2) Anything that I can conceive of is logically possible.
(P3) If it is logically possible that X (mind) exists without Y (body), then X (mind) is not identical to Y (body).
(C) Therefore, I, a thinking thing, am not identical with my extended body.
Recall from the 1st meditation where Descartes shows that we can doubt everything, including the existence of our own physical body, except that we think and that we exist. Because we can conceive of ourselves as existing without having a body, we must not be identical to our body. Since we are not identical to our body, our minds and our bodies must be 2 completely different sorts of things (he calls them "substances").
Most philosophers reject this argument because it relies on Hume's law (P2) which most contemporary philosophers also reject. Conceivability is not sufficient for logical possibility.
Another reason for rejecting the argument is that while Descartes may be correct in that thought is essential to mind and extension is essential to bodies, it doesn't follow that this is all there is to each. He argues that since the essence of mind is thought, he "can infer correctly that my essence consists solely in the fact that I am a thinking thing." But just because thought is an essential property of mind it doesn't necessarily follow that this is the only property of mind. In other words, he can't make that inference.
Alright, for our purposes, this should suffice...
Next argument:
The Divisibility Argument
We can present it simply like this:
(P1) All extended things are divisible. (It's possible to divide the body or matter into parts)
(P2) Minds are not divisible. (When you introspect, you can't distinguish parts of the mind within yourself).
(P3) Although it appears as though my mind and body are united, if I were to remove body parts, "nothing would have been taken away from the mind", thus, minds are not extended.
(C) Therefore, it follows that the minds are distinct substances from bodies.
Most contemporary philosophers (and brain scientists) reject (P3). We know that if we remove parts of the brain, part of our "mind" will also be removed. Also, when the corpus callosum (the bundle of nerves connecting the two hemispheres) is removed, the "mind" seems to divide into two separate consciousnesses.
While it's interesting to dissect what when wrong in Descartes arguments, the more interesting philosophical area is to look at the problems that arise if we accept (or reject) dualism. Recent psychological studies show that most people are natural dualists (i.e., they believe in a non-material mind/soul/spirit/etc...). Not that it matters what the unwashed masses think (I kid! I kid!) but it's interesting to inquire what sorts of problems come about from accepting dualism. Very early on, the very astute Princess Elizabeth of Bohemia noticed some of these problems and presented them to Descartes in written correspondence...which is the topic of the next post...
Monday, September 26, 2011
Dueling with Dualism Part 1
Is The Fundamental Level of Reality Divided into Mind and Body? Or Are Mind and Body Two Aspects of an Even More Fundamental Reality?
The answer to this question is the key distinction between Descartes and Spinoza. Lets unpack the two positions: In the Dualist view (Descartes) anything that exists is either an extended substance (Body) or a thinking substance (Mind). There is nothing more fundamental than these two types of substance; that is to say Mind and Body are not properties of some more fundamental substance. All properties either inhere in the substances of Mind or Body.
Descartes' Position
So how do we know there isn't a more fundamental level of existence? The reason is that these two categories are conceptually distinct: if something is a body then we can identify it as such without appeal to anything beyond the properties of Body, the same is true of Mind. For example, consider the table in front of you: every single property you can attribute to the table (shape, extension, texture, weight, etc...) is a property of Body. We do not (and indeed cannot) invoke any properties of Mind to identify the table as being a body. In another case consider how you would identify your own mind: any property that you would use to identify your mind as your own mind (thought, imagination, feelings, etc...) is a property of Mind and not of Body (body's don't think). Because of this feature of "self-conception", substances are conceptually distinct from each other--they are conceptually walled off from each other. To repeat: to identify a substance as a substance I should not need to refer to properties other than those properties which pertain to that particular substance.
So why does Descartes think that all existing things are made up of either Mind or Body? Because these notions are conceptually distinct/walled off from each other. But there is an important assumption here that Descartes makes: that a substance can have only one attribute (for Mind it is thought and for Body it is extension). Lets ignore for a moment that humans--by Descartes own admission--seem to possess both and ask if this is a good assumption. This is the angle from which Spinoza attacks Descartes.
Spinoza vs Descartes
Spinoza is an uber-rationalist which means that for every fact in the world, there must be an explanation, otherwise we cannot claim to know if a fact is true. This principle of Spinoza's rationalism is called "the Principle of Sufficient Reason" (PSR). But the demand for explanations doesn't end there; Spinoza also applies the PSR to facts about non-existence. For instance, if something doesn't exist, we need to provide a sufficient reason to explain why it can't exist.
So lets get back to Descartes assertion that a substance can only have one attribute. Spinoza rejects Descartes assumption because he hasn't given sufficient reason for which we should believe this. Spinoza argues that we have no reason to suppose that a substance couldn't possess 2 or more attributes. Just because thought and extension are conceptually distinct notions doesn't mean that a thing could not possess both. Another way to look at is, just because two things are conceptually different doesn't necessarily imply that they constitute two different substances.
This argument is partly how Spinoza advances his own position of Monism. So, what's Monism? In Spinoza's case it is the idea that Mind and Body are just two of many possible aspects of the one and only substance. Since there is no sufficient reason to show that a substance can't have more than one attribute, Monism the logical conclusion.
Well, that's half the argument. The other half concerns why Monism must be the case, because simply showing that something is a possibility isn't grounds for its truth. But I will leave that argument for next time. For now, I'll end with a few random comments on what Monism is for Spinoza:
The one substance in which all things inhere is God. But this is not some mystical and/or anthropomorphized god who (magically) lives outside of time and space and is not subject to the laws of the natural world. God, for Spinoza, is nature. God is not some entity that partakes in Nature either. The two are one and the same. Nature is the substance of which all things are properties, or modes. Nature has an absolute infinite number of attributes of which Mind and Body are but two. Because Spinoza's views were basically philosophical naturalism, Spinoza didn't publish his work during his lifetime because he knew he'd probably end up dying the death for his views. Instead he had his friends publish his works after his death.
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