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 Descartes. Show all posts
Showing posts with label Descartes. 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 2, 2013
Berkeley: The Argument for Idealism and the Argument Against Skepticism
Introduction and Context: Locke and Primary and Secondary Properties
To really understand Berkeley's arguments, you have to understand what issues and positions he was responding to. Descartes left us with a problem: Since we can never "get out of our own heads," how do we know that our ideas and perceptions of the external world of objects resemble what those external objects that cause our perceptions are actually like. Locke calls our inability to directly perceive the external world the problem of the veil of perception (we only have direct access to our perceptions, not the external objects that cause those perceptions). This general model of perception is called representationalism.
We're going to take a quick look at Locke because Berkeley is in large part responding to Locke's solution to this problem. Locke's solution has both a metaphysical component (having to do with the nature of reality) and an epistemological component (how we can know about that reality). Beginning with the metaphysical, it goes something like this (condensed from 500 pages):
Locke's Metaphysical Argument First of all, our perceptions have to be of something. Something has to cause them. The most likely candidate is "stuff out there" in the world (he calls it "substance"). Substances have properties like color, shape, taste, smell, spacio-temporal location, solidity, etc... These properties can be divided into 2 categories: primary and secondary. We can look at these two types properties as inherent and dependent properties (from the metaphysical point of view). I'll elaborate all little more after this example:
Consider the properites of color, extension, and shape to illustrate the difference. Color is a secondary property (i.e., dependent) because it depends for its existence on the primary properties. That is, you cannot have color just randomly floating around in the air. If must exist in something extended and with shape (not to mention spacio-temporal location). This is one argument for the dependence of color.
The other is that color is actually the result of the object's surface properties. The object's surface itself doesn't have a color. When light (full spectrum) hits an object's surface, the particular shape (at the atomic level) of the object's surface (i.e., extension) absorbs some light wavelengths and reflects others. The wavelengths that are reflected are the ones that enter our retina and initiate a causal chain terminating with our perception of a color "in the theatre of our mind." Recall, however, that the lightwave frequency that enters our retina isn't itself colored, it merely has a wavelength that activates certain receptors (e.g., ones that cause "yellow") rather than others (e.g., ones that cause "red").
So, lets quickly recap the metaphysical argument.
(P1) Something outside of us must be causing our perceptions.
(P2) It's most likely external objects which are made of or are substances (Locke isn't clear here).
(P3) The qualities like extension, shape, quantity, etc...are necessary for the object to exist as a physical entity. Lets call them primary qualities.
(P4) The qualities like color, texture, taste, and sound depend for their existence on the primary qualities. Lets call them secondary qualities.
(P5) It's not possible for a secondary property to exist on its own, whereas primary properties can. These names are a good description of the qualities.
(C) Substances have 2 classes of properties: Primary and Secondary.
The external objects that cause our perceptions have primary and secondary properties. Primary properties are objective and will be perceived regardless the nature of a perceiver's perceptual system or point of view because they inhere in the objects.
Now, lets put on our epistemologist hats.
How can we know about the external world based on our perceptions of it since all we have access to are the ideas inside our heads? (I.e., how can we know that the properties that an external object have "match up" with the image we have of it projected in our heads)
Recall that the primary qualities include extension, solidity, motion, quantity, spacio-temporal location, and shape. All external objects, when they are perceived, must have these properties in order to be perceived. For instance, could you perceive an object that isn't extended? (i.e., that doesn't occupy space?) Could you perceive an object that has no shape? Locke says "no," and this is evidence of the fact that primary qualities are necessarily in the objects we perceive rather than simply in our pointy little heads.
We can therefore know that our perceptions of external objects and those external objects themselves "match up" in terms of primary qualities. It follows that, we can know stuff about the primary qualities of objects in the world as well as about the relations between those primary qualities in objects.
Secondary qualities are subjective: that is, the way each individual perceives them is a product of how our particular perceptual system works. It might very well be that my purple is your red and vice versa. There is no way to ever know. For this reason, our perceptions of secondary qualities don't give us any information about how the "real" world is outside of our perceptions.
Ok, I think that should be (more than) enough to get us started...
Berkeley's Idealism and Its Motivations
Key Idea: "[. . .] the very existence of an unthinking being consists in being perceived."
We can summarize Berkeley's position like this: The only thing we have direct access to with our minds is ideas (i.e., images, memories, perceptions). This means that we can only know that 2 types of things are real and exist: ideas and the minds that perceive them. Knowledge consists in the apprehension of the contents of our minds (ideas) and the regular relations between them. Furthermore, the notion of "matter" or "material substance" is incoherent and therefore cannot exist.
Epistemological Motivation:
I'll get to it a bit later, but he further argues that we don't need to posit physical objects to explain how ideas get into our minds. In fact, by not positing physical objects we completely avoid the epistemological problem of the veil of perception; i.e., trying to figure out if our perceptions of external objects match up with up with external objects themselves. Also, we sidestep the veil of perception problem, we also avoid the problem of skepticism.
Metaphysical Motivation:
With idealism, we also avoid a metaphysical problem: supposing the there are only 2 types of things in the universe, matter and minds, how is it possible for these things to interact causally? Consider the following: matter has the properties of extension, shape, solidity, and most importantly a spacial location. Minds on the other hand don't have any of these properties (extension, shape, solidity, nor do they exist in any spacial location), their only properties are ideas. So how the crap can a physical object (i.e., matter) cause something to happen in a mind (which doesn't have any of the properties of matter)? This problem is further exacerbated when we consider that matter can't have mental properties (ideas).
Destructive Arguments: Why Positing Matter as the Cause of Ideas Is Incoherent
The first part of Berkeley's project is to show that the materialist conception of the world is incoherent.
Groundwork: The Argument Against "Resemblance"
Before going directly after the materialist conception of the world (i.e., the position that there are physical substances), Berkeley lays down the groundwork with the following argument against the notion of resemblance between ideas and material objects:
Materialist say that our ideas of physical objects resemble the physical objects themselves. For example, when I look at a cat, the idea (i.e., perception) which the actual cat causes me to have in my mind resembles the actual cat outside my mind.
Berkeley says this notion of resemblance is a mistake: the only thing that can resemble an idea is other idea. Recall that ideas are something that minds have--physical objects can't have ideas. That is, ideas have very different properties from physical things--ideas, unlike physical objects, don't have a spacial location, for example. Because the properties possessed by physical things and the properties of ideas are so completely different, it is not possible for ideas to resemble physical things.
To repeat: the only thing that can resemble an idea is another idea. From this it follows that extension can only resemble extension, solidity can only resemble solidity, color can only resemble color, and so on... Ideas cannot resemble objects that have the properties of matter because ideas can only resemble ideas (and ideas don't have the properties of matter).
Collapse of Primary and Secondary Qualities Distinction
Recall that materialists (like Descartes and Locke) hold that not all properties have the same metaphysical and epistemological status. Secondary properties only exist as a consequence of primary qualities. Also secondary properties are a consequence of how our perceptual system works and are therefore subjective, while primary qualities are objective because we perceive shape, extension, quantity the same regardless of our perceptual system or point of view.
For example, you can't experience a circular object as triangular no matter how your perceptual system is configured because the circular shape inheres in the physical object whereas something like color isn't and is added by our minds.
Ok, so in this part of the argument (9-15 PHK) Berkeley wants to further show that the mere concept of a hierarchy of properties is incoherent: All properties are metaphysically and epistemically equal. And, contrary to the materialist hypothesis, all properties inhere in mind.
The argument goes something like this: Try to imagine a physical object that possesses the "primary" properties of extension and motion. Go ahead, do it. Now, is it possible for you to do it without also imagining the object with some color, no matter how faint? I don't know about you, but I can't do it. Even if I just imagine the outline of a figure, that outline still has a color.
So, what does this mean? What Berkeley does next is very clever. He says, look youz guys (referring to materialists): You say that secondary properties only exist as ideas in the mind, but we have just shown that you cannot imagine a material object's primary qualities without its secondary properties (like color). It follows that what you call primary (objective) properties require for their perception that there be secondary properties.
The dependance relation between primary and secondary is mutual rather than only secondary depending on primary properties. You cannot "abstract away" primary qualities from secondary qualities, both are required for perception of objects. And since, as you say, "secondary" properties are mental, both primary and secondary properties must be mental because how could a physical property depend on for its existence a mental property?
Anti-Abstraction Argument
If that isn't clear, he gives another formulation of the argument which emphasizes the role of abstraction in Berkeley destruction of the primary/secondary distinction. It goes like this:
The only way to conceive of the properties of pure extension or shape is to abstract them from a compound idea of an object (i.e. one with both primary and secondary qualities). Objects don't have "pure" extension or shape without color. We have to abstract those to properties out. And when we engage in the act of abstraction, where do those "primary" qualities exist? They exist only in the mind. That is, since abstraction is a mental activity, pure extension and shape can exist only as ideas, and therefore those properties must be mental properties (i.e., ideas).
More Examples:
Quantity: The materialists argue that quantity is an objective property of objects. However, Berkeley argues it is clearly a subjective mental quality because something's quantity will depend on how we want to "chop it up." For example, I might say my chair is 2ft high or 24" high or 60cm high. The number I use to measure distance is totally subjective.
Likewise I might say there is one book, or 350 pages, or 345,660 words. It's entirely up to me how I want to conceive an object of perception and what units I'd like to use to describe it.
The Master Argument for Idealism
In 22-23 (PHK), Berkeley gives what is called "the master argument" because he seems to think that even if you reject all the other arguments, this argument shows that the only place anything can exist is in the mind. (And since anything that exists in the mind is an idea, the only things that exist are ideas and minds). He begins:
I am content to put the whole issue upon this issue; if you an but conceive it possible for one extended moveable substance, or in general, for any one idea or any thing like an idea, to exist otherwise than in a mind perceiving it, I shall readily give up the causes.
So what does all this mean? Essentially, he is arguing that the only place anything can exist in is the mind as an idea.
For example, can you imagine a color that is unperceived? Ah ha! No, you can't because in order to do so, you have to imagine it, and thereby perceive it in your mind. Can you imagine an extended object that is unperceived? Ah ha! No you can't! To do so requires that you imagine that object, thereby proving it exists in the mind, not "out there"! It is impossible to think of a physical property or object that exists unperceived (outside the mind) because anytime you think do, ta da! you're perceiving it (as an idea).
As Berkeley says, [you cannot conceive of anything existing outside the mind because doing so] only shows you have the power of imagining or forming ideas in your mind: to make out this, it is necessary that you conceive them existing unconceived or unthought of, which is a manifest repugnancy (i.e., absurdity).
Implications of Idealism: Minds and Ideas
If we agree with Berkeley's reasoning up to this point it seems we have to reject the notion of mind-independent objects. What follows from this is that the only things that exist are minds (aka spirits, souls) and ideas (aka perceptions, conceptions, memories). Minds are "active, indivisible substances" and ideas are "inert, fleeting, dependent beings." Therefore, objects only exist as ideas in minds. ([. . .] the very existence of an unthinking being consists in being perceived.)
We know that we exist through internal reflection and introspection; we can know other minds exist through reason. (This will present problems as we will see in the next post on Russell and the problem of solipsism.)
Possible Objection and Reply
One possible objection to the view revolves around how we explain where ideas of external objects come from. If there are no external physical objects, what are causing my perceptions? Berkeley replies that we can call the things which we perceive via our senses "external" in terms of their origin, but they needn't be composed of matter. They exist and come from other minds. In particular, from God's mind. So, if I close my eyes, the object I was looking at doesn't cease to exist, but continues to exist in God's mind.
To really understand Berkeley's arguments, you have to understand what issues and positions he was responding to. Descartes left us with a problem: Since we can never "get out of our own heads," how do we know that our ideas and perceptions of the external world of objects resemble what those external objects that cause our perceptions are actually like. Locke calls our inability to directly perceive the external world the problem of the veil of perception (we only have direct access to our perceptions, not the external objects that cause those perceptions). This general model of perception is called representationalism.
We're going to take a quick look at Locke because Berkeley is in large part responding to Locke's solution to this problem. Locke's solution has both a metaphysical component (having to do with the nature of reality) and an epistemological component (how we can know about that reality). Beginning with the metaphysical, it goes something like this (condensed from 500 pages):
Locke's Metaphysical Argument First of all, our perceptions have to be of something. Something has to cause them. The most likely candidate is "stuff out there" in the world (he calls it "substance"). Substances have properties like color, shape, taste, smell, spacio-temporal location, solidity, etc... These properties can be divided into 2 categories: primary and secondary. We can look at these two types properties as inherent and dependent properties (from the metaphysical point of view). I'll elaborate all little more after this example:
Consider the properites of color, extension, and shape to illustrate the difference. Color is a secondary property (i.e., dependent) because it depends for its existence on the primary properties. That is, you cannot have color just randomly floating around in the air. If must exist in something extended and with shape (not to mention spacio-temporal location). This is one argument for the dependence of color.
The other is that color is actually the result of the object's surface properties. The object's surface itself doesn't have a color. When light (full spectrum) hits an object's surface, the particular shape (at the atomic level) of the object's surface (i.e., extension) absorbs some light wavelengths and reflects others. The wavelengths that are reflected are the ones that enter our retina and initiate a causal chain terminating with our perception of a color "in the theatre of our mind." Recall, however, that the lightwave frequency that enters our retina isn't itself colored, it merely has a wavelength that activates certain receptors (e.g., ones that cause "yellow") rather than others (e.g., ones that cause "red").
So, lets quickly recap the metaphysical argument.
(P1) Something outside of us must be causing our perceptions.
(P2) It's most likely external objects which are made of or are substances (Locke isn't clear here).
(P3) The qualities like extension, shape, quantity, etc...are necessary for the object to exist as a physical entity. Lets call them primary qualities.
(P4) The qualities like color, texture, taste, and sound depend for their existence on the primary qualities. Lets call them secondary qualities.
(P5) It's not possible for a secondary property to exist on its own, whereas primary properties can. These names are a good description of the qualities.
(C) Substances have 2 classes of properties: Primary and Secondary.
The external objects that cause our perceptions have primary and secondary properties. Primary properties are objective and will be perceived regardless the nature of a perceiver's perceptual system or point of view because they inhere in the objects.
Now, lets put on our epistemologist hats.
How can we know about the external world based on our perceptions of it since all we have access to are the ideas inside our heads? (I.e., how can we know that the properties that an external object have "match up" with the image we have of it projected in our heads)
Recall that the primary qualities include extension, solidity, motion, quantity, spacio-temporal location, and shape. All external objects, when they are perceived, must have these properties in order to be perceived. For instance, could you perceive an object that isn't extended? (i.e., that doesn't occupy space?) Could you perceive an object that has no shape? Locke says "no," and this is evidence of the fact that primary qualities are necessarily in the objects we perceive rather than simply in our pointy little heads.
We can therefore know that our perceptions of external objects and those external objects themselves "match up" in terms of primary qualities. It follows that, we can know stuff about the primary qualities of objects in the world as well as about the relations between those primary qualities in objects.
Secondary qualities are subjective: that is, the way each individual perceives them is a product of how our particular perceptual system works. It might very well be that my purple is your red and vice versa. There is no way to ever know. For this reason, our perceptions of secondary qualities don't give us any information about how the "real" world is outside of our perceptions.
Ok, I think that should be (more than) enough to get us started...
Berkeley's Idealism and Its Motivations
Key Idea: "[. . .] the very existence of an unthinking being consists in being perceived."
We can summarize Berkeley's position like this: The only thing we have direct access to with our minds is ideas (i.e., images, memories, perceptions). This means that we can only know that 2 types of things are real and exist: ideas and the minds that perceive them. Knowledge consists in the apprehension of the contents of our minds (ideas) and the regular relations between them. Furthermore, the notion of "matter" or "material substance" is incoherent and therefore cannot exist.
Epistemological Motivation:
I'll get to it a bit later, but he further argues that we don't need to posit physical objects to explain how ideas get into our minds. In fact, by not positing physical objects we completely avoid the epistemological problem of the veil of perception; i.e., trying to figure out if our perceptions of external objects match up with up with external objects themselves. Also, we sidestep the veil of perception problem, we also avoid the problem of skepticism.
Metaphysical Motivation:
With idealism, we also avoid a metaphysical problem: supposing the there are only 2 types of things in the universe, matter and minds, how is it possible for these things to interact causally? Consider the following: matter has the properties of extension, shape, solidity, and most importantly a spacial location. Minds on the other hand don't have any of these properties (extension, shape, solidity, nor do they exist in any spacial location), their only properties are ideas. So how the crap can a physical object (i.e., matter) cause something to happen in a mind (which doesn't have any of the properties of matter)? This problem is further exacerbated when we consider that matter can't have mental properties (ideas).
Destructive Arguments: Why Positing Matter as the Cause of Ideas Is Incoherent
The first part of Berkeley's project is to show that the materialist conception of the world is incoherent.
Groundwork: The Argument Against "Resemblance"
Before going directly after the materialist conception of the world (i.e., the position that there are physical substances), Berkeley lays down the groundwork with the following argument against the notion of resemblance between ideas and material objects:
Materialist say that our ideas of physical objects resemble the physical objects themselves. For example, when I look at a cat, the idea (i.e., perception) which the actual cat causes me to have in my mind resembles the actual cat outside my mind.
Berkeley says this notion of resemblance is a mistake: the only thing that can resemble an idea is other idea. Recall that ideas are something that minds have--physical objects can't have ideas. That is, ideas have very different properties from physical things--ideas, unlike physical objects, don't have a spacial location, for example. Because the properties possessed by physical things and the properties of ideas are so completely different, it is not possible for ideas to resemble physical things.
To repeat: the only thing that can resemble an idea is another idea. From this it follows that extension can only resemble extension, solidity can only resemble solidity, color can only resemble color, and so on... Ideas cannot resemble objects that have the properties of matter because ideas can only resemble ideas (and ideas don't have the properties of matter).
Collapse of Primary and Secondary Qualities Distinction
Recall that materialists (like Descartes and Locke) hold that not all properties have the same metaphysical and epistemological status. Secondary properties only exist as a consequence of primary qualities. Also secondary properties are a consequence of how our perceptual system works and are therefore subjective, while primary qualities are objective because we perceive shape, extension, quantity the same regardless of our perceptual system or point of view.
For example, you can't experience a circular object as triangular no matter how your perceptual system is configured because the circular shape inheres in the physical object whereas something like color isn't and is added by our minds.
Ok, so in this part of the argument (9-15 PHK) Berkeley wants to further show that the mere concept of a hierarchy of properties is incoherent: All properties are metaphysically and epistemically equal. And, contrary to the materialist hypothesis, all properties inhere in mind.
The argument goes something like this: Try to imagine a physical object that possesses the "primary" properties of extension and motion. Go ahead, do it. Now, is it possible for you to do it without also imagining the object with some color, no matter how faint? I don't know about you, but I can't do it. Even if I just imagine the outline of a figure, that outline still has a color.
So, what does this mean? What Berkeley does next is very clever. He says, look youz guys (referring to materialists): You say that secondary properties only exist as ideas in the mind, but we have just shown that you cannot imagine a material object's primary qualities without its secondary properties (like color). It follows that what you call primary (objective) properties require for their perception that there be secondary properties.
The dependance relation between primary and secondary is mutual rather than only secondary depending on primary properties. You cannot "abstract away" primary qualities from secondary qualities, both are required for perception of objects. And since, as you say, "secondary" properties are mental, both primary and secondary properties must be mental because how could a physical property depend on for its existence a mental property?
Anti-Abstraction Argument
If that isn't clear, he gives another formulation of the argument which emphasizes the role of abstraction in Berkeley destruction of the primary/secondary distinction. It goes like this:
The only way to conceive of the properties of pure extension or shape is to abstract them from a compound idea of an object (i.e. one with both primary and secondary qualities). Objects don't have "pure" extension or shape without color. We have to abstract those to properties out. And when we engage in the act of abstraction, where do those "primary" qualities exist? They exist only in the mind. That is, since abstraction is a mental activity, pure extension and shape can exist only as ideas, and therefore those properties must be mental properties (i.e., ideas).
More Examples:
Quantity: The materialists argue that quantity is an objective property of objects. However, Berkeley argues it is clearly a subjective mental quality because something's quantity will depend on how we want to "chop it up." For example, I might say my chair is 2ft high or 24" high or 60cm high. The number I use to measure distance is totally subjective.
Likewise I might say there is one book, or 350 pages, or 345,660 words. It's entirely up to me how I want to conceive an object of perception and what units I'd like to use to describe it.
The Master Argument for Idealism
In 22-23 (PHK), Berkeley gives what is called "the master argument" because he seems to think that even if you reject all the other arguments, this argument shows that the only place anything can exist is in the mind. (And since anything that exists in the mind is an idea, the only things that exist are ideas and minds). He begins:
I am content to put the whole issue upon this issue; if you an but conceive it possible for one extended moveable substance, or in general, for any one idea or any thing like an idea, to exist otherwise than in a mind perceiving it, I shall readily give up the causes.
So what does all this mean? Essentially, he is arguing that the only place anything can exist in is the mind as an idea.
For example, can you imagine a color that is unperceived? Ah ha! No, you can't because in order to do so, you have to imagine it, and thereby perceive it in your mind. Can you imagine an extended object that is unperceived? Ah ha! No you can't! To do so requires that you imagine that object, thereby proving it exists in the mind, not "out there"! It is impossible to think of a physical property or object that exists unperceived (outside the mind) because anytime you think do, ta da! you're perceiving it (as an idea).
As Berkeley says, [you cannot conceive of anything existing outside the mind because doing so] only shows you have the power of imagining or forming ideas in your mind: to make out this, it is necessary that you conceive them existing unconceived or unthought of, which is a manifest repugnancy (i.e., absurdity).
Implications of Idealism: Minds and Ideas
If we agree with Berkeley's reasoning up to this point it seems we have to reject the notion of mind-independent objects. What follows from this is that the only things that exist are minds (aka spirits, souls) and ideas (aka perceptions, conceptions, memories). Minds are "active, indivisible substances" and ideas are "inert, fleeting, dependent beings." Therefore, objects only exist as ideas in minds. ([. . .] the very existence of an unthinking being consists in being perceived.)
We know that we exist through internal reflection and introspection; we can know other minds exist through reason. (This will present problems as we will see in the next post on Russell and the problem of solipsism.)
Possible Objection and Reply
One possible objection to the view revolves around how we explain where ideas of external objects come from. If there are no external physical objects, what are causing my perceptions? Berkeley replies that we can call the things which we perceive via our senses "external" in terms of their origin, but they needn't be composed of matter. They exist and come from other minds. In particular, from God's mind. So, if I close my eyes, the object I was looking at doesn't cease to exist, but continues to exist in God's mind.
Wednesday, August 28, 2013
Descartes and the First Meditation: What Can We Know for Sure?
Introduction to Descartes Meditation I
Descartes' Meditations is one of the most important works in modern philosophy (i.e., 17th Century philosophy). It is the point of departure for many philosophical issues and debates up to and including the present. The overall aim of his project is to determine what we can know beyond any possible doubt; that is, what constitutes genuine knowledge. Once we figure out what beliefs are beyond any possible doubt, it is suggested, we can use reason to deduce the rest of what is knowable.
Meditation I is the "destructive" phase of Descartes project. He's going to try to destroy his own confidence in as many of his beliefs as he can. In other words, Descartes is going to show why he can doubt, and therefore reject, just about any of his beliefs. (Spoiler alert: except that he has thoughts and therefore exists).
Philosophical Importance and Context:
One last point before we look at his specific arguments and methods: the context of this whole exercise is important to the philosophical debate between rationalists and empiricists over the source of scientific knowledge. Rationalists believe that true knowledge comes from within; that is, the only beliefs that we can really know are true are those that we access through introspection. Empiricists, on the other hand, argue that if we want to know anything, we have to look at the world: the source of all knowledge comes from empirical observation and experience.
This roots of this debate actually reach back to Plato vs Aristotle and it still rage on today in various incarnations; nevertheless, we're going to pick things up beginning with Descartes.
Vocabulary:
Although I'll do my best to avoid jargon, there are 2 technical terms that are impossible to avoid in the study of epistemology and most philosophy, so we might as well get them out of the way right now:
A priori: This means "before experience." It refers to the category of beliefs we can have without having to go out into the world to verify their truth. For example, you don't need to go running around with a measuring stick to know that the shortest distance between any two points is a straight line.
Similarly, if you know that the interior angles of a triangle = 180 degrees, then, given either only 2 interior angles or an interior angle and the length of the adjacent side, you can infer the other 2 angles. You don't have to go measure each triangle to verify. We can know the angles will be right before we measure.
Definitional truths also fall into this category, like "all bachelors are unmarried men." We can know this before empirical experience. All we need is an understanding of the two concepts "bachelors" and "unmarried men." You don't need to go around interviewing bachelors to find out if they are also unmarried.
A posteriori: This means "after experience." A posteriori knowledge refers to beliefs that we can only know as true once we have gone out into the world and verified them. For example, "apples are red" or "Miley Cyrus danced with giant teddy bears." Before we can know whether these beliefs about the world are true or not, we'll need some sort of empirical evidence.
Part 1: Explanation of Method. Method of Doubt
In the first part of the 1st Meditation, Descartes takes a moment to explain what he's about to do. He says something along the lines of:
Have you ever had the experience where you realize that something you thought was true as a child turned out to be false? Or maybe it was only a few years ago that you thought Santa was real...
The point being, few of us ever stick with the exact same set of beliefs for the entire duration of our lives. Sometimes our experiences teach us that a previously held belief was false. So, why should we suppose that at this particular point in our lives, all of our beliefs are true? I mean, seriously, given all the different conflicting beliefs in the world about the 1000s of different possible topics, what are the chances that YOU, at this particular moment in time, just happen to have stumbled upon all of the true ones and EVERYBODY ELSE, except you, has some false beliefs? Take a moment to do the calculation if you like...
So, here's the problem. Supposing that some of my current beliefs are false, how am I to distinguish them from the true ones if I know that some that I previously believe to be true turned out to be false (Curse you Santa!). How do we tell in advance which beliefs are true and which are false?
His solution to this problem is to treat any belief that has even the remotest possibility of being false, as false. That is, he will not only reject beliefs that can be shown to be false, but also beliefs that could be false--even though maybe he can't show them to be false.
The net result will be that whatever beliefs cannot possibly be false will necessarily be true. Once he establishes all the necessarily true beliefs (the ones that withstood all doubt), he can deduce the rest of his knowledge. In other words, since many beliefs rest on a foundation of prior more fundamental beliefs, if we can establish a firm foundation, then we can construct a strong edifice of knowledge.
Let's formalize the method:
Suppose we want to know if something (P) is true.
(P1) The only way I can know for sure that P is true is if I cannot possibly doubt its truth.
(P2) But I can doubt P is true.
(C) Therefore, I do not know that P.
('P', in philosophy, usually stands for "some proposition" kind of like how 'x' is used in math to represent "some number")
Now, lets go back and look a little bit more at that previous idea--the edifice of knowledge built on a firm foundation. Descartes' idea of the "structure" of knowledge is what's known as foundationalism. Foundationalism is the theory that all beliefs (or knowledge) ultimately depend on other more basic beliefs, which in turn depend on more basic beliefs, and so on until you get to the beliefs that are foundation of all your beliefs. In short, the structure of knowledge is heirachical.
Because of the "shape" of knowledge in Descartes' foundationalism, you can deduce or infer higher level beliefs from the more basic beliefs...kind of like doing geometry or arithmetic. (This is no coincidence since Descartes was primarily a mathematician and geometer. If I know from the rules of arithmetic that 1+1=2, then I can infer that 2+1=3 and so on. I can infer from my basic knowledge of the rules new knowledge that I didn't have previously.
So, why were we talking about foundationalism anyway? Oh right...because instead of Descartes' piecemeal going through every single one of his beliefs and subjecting them each to doubt (is this really a chair I'm sitting on? Is it really black? Did Miley Cyrus really just do that?) he can shorten the process by only looking at the foundational beliefs. If the foundational beliefs are subject to doubt then everything else that's built on them will also come a tumblin' down.
The Argument from the Unreliability of the Senses:
Sometimes when I see a tower from a distance, it looks rectangular, but when I ride my horse up close to it, the tower is in fact round! Or sometimes when I'm walking my dogs at night, I think I see another dog in the distance, but in fact it's just a garbage can.
Given that my senses can fool me, why should I put any stock in my sensorily acquired beliefs? As a famous man once said
But, Descartes realizes that if he were to fully commit to this argument, his position would be no different from that of a raving madman--it's a bit too crazy. Sure, we can all agree that sometimes under certain conditions our senses fool us about the external world, but it's a bit of a stretch to move from that to the idea that we can't trust anything our senses tell us.
Lets quickly formalize the argument:
(P1): Sometimes my senses fool me.
(P2): I can't distinguish between when they are fooling me and when they aren't.
(C1): Given (P1) and (P2), I can't confidently say that my sensorily acquired beliefs are true.
Counter argument: Simply because my senses sometimes deceive me about the external world, it doesn't necessarily follow that I should reject all sensorily derived beliefs. Maybe the one's that are most obvious, like "I have a body" or "the chair I'm sitting on is solid," are more probably true than untrue.
So, where are a priori beliefs in all this? So far, the argument from the unreliability of the senses leaves them untouched. The ability for our senses to fool us about the external world has no effect on the truth of "all bachelors are unmarried men" or "the shortest distance between 2 points is a straight line." I don't need the outside world to know that these assertions are true--all I need is an understanding of the relevant concepts.
The Dream Argument (Argument vs Empirically-Acquired Beliefs)
Sometimes when I'm dreaming I imagine I'm flying but I'm actually lying in my bed. Or maybe I dream that my arm is cut off or that I'm late for class, but that's not what's actually happening. Surely, we can all agree that we've been fooled by dreams that seemed real at the time we were dreaming.
This raises a problem: How do can we distinguish between when we're dreaming and when we're awake? How do I know whether I'm a butterfly dreaming he's a human or a human dreaming he's a butterfly? Because I can sometimes fail to make this distinction, it follows that I can't be sure that my beliefs about the external world are entirely free from any doubt.
Lets formalize the argument:
(P1) When we are dreaming, we cannot always distinguish whether we are dreaming or whether we are awake.
(P2) It follows from P1 that there will be times when we think we are awake and form beliefs about the world but in fact we aren't awake, and so those beliefs are actually false.
(C) Therefore, it is possible to doubt the truth of our beliefs about the external world.
Descartes brings up a possible counter argument: Lets suppose I am dreaming and in my dream I have purple octopus arms and the head of a dragon. Surely, this does not match up to the world as it is. However, all the perceptions of the basic constituent parts of my dream, like the color purple, the shapes, the textures, size, quantity, temporal duration and so on, all had to have come from somewhere. As he says:
[...] it surely must be admitted that the things seen during slumber are, as it were, like painted images, which could only have been produced in the likeness of true things, and that therefore at least these general things--eyes, head, hands, and the whole body--are not imaginary things, but are true and exist.
In short, you cannot imagine things ex nihilo (out of nothing); the original building blocks of your ideas have to originate from somewhere besides the inside of your head.
What follows from this? Here Descartes argues that because we are able to mix and match general and universal qualities in any manner of ways in our dreams and imagination (and sometimes we can't tell when we're dreaming) we must doubt truths that are about composite ideas. That is, ideas about things other than the fundamental properties of our thoughts. Some examples of things about which we can doubt are physics, astronomy, medicine (because they are about composite things).
So, what types of beliefs does the dream argument leave untouched? The answer is beliefs about disciplines that trade in a priori beliefs; that is beliefs about things we don't have to go out in the world to verify for truth. Arithmetic, geometry, for example, don't require for us to go out into the world to verify the truth of their assertions.
For example, when I divide 100 by 25 and give the answer of 4, I don't need to go out and physically manipulate things into piles to verify this truth. So long as I correctly follow the rules of arithmetic, I'll have the right answer. Not only will I have the right answer, but I'll have the right answer whether I'm dreaming or not. That is, regardless of whether I'm dreaming, so long as I follow the rules of arithmetic, I'll have the correct answer.
The same applies for geometric proofs. A square will have 4 sides whether I'm dreaming or not. If it doesn't, then it's no longer a square--it's something else. The same also applies to the bachelor example...and all a priori knowledge.
Aside
In the next section there's a little digression where Descartes talks about the possibility that his creator, if he so chose, would be able to be deceive him even about algebraic and geometric facts (i.e., a priori beliefs). Then he remarks that the combination of the 2 arguments and the possibility the God could deceive him are not quite enough to break him of his habit of trusting his sensorily-derived and a priori beliefs. He finds himself slipping back into the habit of assenting to them because it's "much more consistent with reason to believe them than to deny them." The same applies to God as a willful deceiver.
To prevent himself from slipping back into his old ways and to help him stick to his project of trying to reject any belief that it is possible to doubt, he's going to need a stronger method.
Enter the demon argument...(cue ominous music)
The Demon Argument (Or the Matrix)
Here we are to imagine a powerful evil genius who has dedicated himself to deceiving us. Everything you experience has been constructed by the evil genius. Here's the modern equivalent of the argument
The idea is this: All of your thoughts are being fed to you by an evil genius or a computer program--take your pick. Supposing this scenario, what can we know, that is, what beliefs can we have that we can be 100% sure are true?
If you've read the 2nd meditation, then you know...
Descartes' Meditations is one of the most important works in modern philosophy (i.e., 17th Century philosophy). It is the point of departure for many philosophical issues and debates up to and including the present. The overall aim of his project is to determine what we can know beyond any possible doubt; that is, what constitutes genuine knowledge. Once we figure out what beliefs are beyond any possible doubt, it is suggested, we can use reason to deduce the rest of what is knowable.
Meditation I is the "destructive" phase of Descartes project. He's going to try to destroy his own confidence in as many of his beliefs as he can. In other words, Descartes is going to show why he can doubt, and therefore reject, just about any of his beliefs. (Spoiler alert: except that he has thoughts and therefore exists).
Philosophical Importance and Context:
One last point before we look at his specific arguments and methods: the context of this whole exercise is important to the philosophical debate between rationalists and empiricists over the source of scientific knowledge. Rationalists believe that true knowledge comes from within; that is, the only beliefs that we can really know are true are those that we access through introspection. Empiricists, on the other hand, argue that if we want to know anything, we have to look at the world: the source of all knowledge comes from empirical observation and experience.
This roots of this debate actually reach back to Plato vs Aristotle and it still rage on today in various incarnations; nevertheless, we're going to pick things up beginning with Descartes.
Vocabulary:
Although I'll do my best to avoid jargon, there are 2 technical terms that are impossible to avoid in the study of epistemology and most philosophy, so we might as well get them out of the way right now:
A priori: This means "before experience." It refers to the category of beliefs we can have without having to go out into the world to verify their truth. For example, you don't need to go running around with a measuring stick to know that the shortest distance between any two points is a straight line.
Similarly, if you know that the interior angles of a triangle = 180 degrees, then, given either only 2 interior angles or an interior angle and the length of the adjacent side, you can infer the other 2 angles. You don't have to go measure each triangle to verify. We can know the angles will be right before we measure.
Definitional truths also fall into this category, like "all bachelors are unmarried men." We can know this before empirical experience. All we need is an understanding of the two concepts "bachelors" and "unmarried men." You don't need to go around interviewing bachelors to find out if they are also unmarried.
A posteriori: This means "after experience." A posteriori knowledge refers to beliefs that we can only know as true once we have gone out into the world and verified them. For example, "apples are red" or "Miley Cyrus danced with giant teddy bears." Before we can know whether these beliefs about the world are true or not, we'll need some sort of empirical evidence.
Part 1: Explanation of Method. Method of Doubt
In the first part of the 1st Meditation, Descartes takes a moment to explain what he's about to do. He says something along the lines of:
Have you ever had the experience where you realize that something you thought was true as a child turned out to be false? Or maybe it was only a few years ago that you thought Santa was real...
The point being, few of us ever stick with the exact same set of beliefs for the entire duration of our lives. Sometimes our experiences teach us that a previously held belief was false. So, why should we suppose that at this particular point in our lives, all of our beliefs are true? I mean, seriously, given all the different conflicting beliefs in the world about the 1000s of different possible topics, what are the chances that YOU, at this particular moment in time, just happen to have stumbled upon all of the true ones and EVERYBODY ELSE, except you, has some false beliefs? Take a moment to do the calculation if you like...
So, here's the problem. Supposing that some of my current beliefs are false, how am I to distinguish them from the true ones if I know that some that I previously believe to be true turned out to be false (Curse you Santa!). How do we tell in advance which beliefs are true and which are false?
His solution to this problem is to treat any belief that has even the remotest possibility of being false, as false. That is, he will not only reject beliefs that can be shown to be false, but also beliefs that could be false--even though maybe he can't show them to be false.
The net result will be that whatever beliefs cannot possibly be false will necessarily be true. Once he establishes all the necessarily true beliefs (the ones that withstood all doubt), he can deduce the rest of his knowledge. In other words, since many beliefs rest on a foundation of prior more fundamental beliefs, if we can establish a firm foundation, then we can construct a strong edifice of knowledge.
Let's formalize the method:
Suppose we want to know if something (P) is true.
(P1) The only way I can know for sure that P is true is if I cannot possibly doubt its truth.
(P2) But I can doubt P is true.
(C) Therefore, I do not know that P.
('P', in philosophy, usually stands for "some proposition" kind of like how 'x' is used in math to represent "some number")
Now, lets go back and look a little bit more at that previous idea--the edifice of knowledge built on a firm foundation. Descartes' idea of the "structure" of knowledge is what's known as foundationalism. Foundationalism is the theory that all beliefs (or knowledge) ultimately depend on other more basic beliefs, which in turn depend on more basic beliefs, and so on until you get to the beliefs that are foundation of all your beliefs. In short, the structure of knowledge is heirachical.
Because of the "shape" of knowledge in Descartes' foundationalism, you can deduce or infer higher level beliefs from the more basic beliefs...kind of like doing geometry or arithmetic. (This is no coincidence since Descartes was primarily a mathematician and geometer. If I know from the rules of arithmetic that 1+1=2, then I can infer that 2+1=3 and so on. I can infer from my basic knowledge of the rules new knowledge that I didn't have previously.
So, why were we talking about foundationalism anyway? Oh right...because instead of Descartes' piecemeal going through every single one of his beliefs and subjecting them each to doubt (is this really a chair I'm sitting on? Is it really black? Did Miley Cyrus really just do that?) he can shorten the process by only looking at the foundational beliefs. If the foundational beliefs are subject to doubt then everything else that's built on them will also come a tumblin' down.
The Argument from the Unreliability of the Senses:
Sometimes when I see a tower from a distance, it looks rectangular, but when I ride my horse up close to it, the tower is in fact round! Or sometimes when I'm walking my dogs at night, I think I see another dog in the distance, but in fact it's just a garbage can.
Given that my senses can fool me, why should I put any stock in my sensorily acquired beliefs? As a famous man once said
But, Descartes realizes that if he were to fully commit to this argument, his position would be no different from that of a raving madman--it's a bit too crazy. Sure, we can all agree that sometimes under certain conditions our senses fool us about the external world, but it's a bit of a stretch to move from that to the idea that we can't trust anything our senses tell us.
Lets quickly formalize the argument:
(P1): Sometimes my senses fool me.
(P2): I can't distinguish between when they are fooling me and when they aren't.
(C1): Given (P1) and (P2), I can't confidently say that my sensorily acquired beliefs are true.
Counter argument: Simply because my senses sometimes deceive me about the external world, it doesn't necessarily follow that I should reject all sensorily derived beliefs. Maybe the one's that are most obvious, like "I have a body" or "the chair I'm sitting on is solid," are more probably true than untrue.
So, where are a priori beliefs in all this? So far, the argument from the unreliability of the senses leaves them untouched. The ability for our senses to fool us about the external world has no effect on the truth of "all bachelors are unmarried men" or "the shortest distance between 2 points is a straight line." I don't need the outside world to know that these assertions are true--all I need is an understanding of the relevant concepts.
The Dream Argument (Argument vs Empirically-Acquired Beliefs)
Sometimes when I'm dreaming I imagine I'm flying but I'm actually lying in my bed. Or maybe I dream that my arm is cut off or that I'm late for class, but that's not what's actually happening. Surely, we can all agree that we've been fooled by dreams that seemed real at the time we were dreaming.
This raises a problem: How do can we distinguish between when we're dreaming and when we're awake? How do I know whether I'm a butterfly dreaming he's a human or a human dreaming he's a butterfly? Because I can sometimes fail to make this distinction, it follows that I can't be sure that my beliefs about the external world are entirely free from any doubt.
Lets formalize the argument:
(P1) When we are dreaming, we cannot always distinguish whether we are dreaming or whether we are awake.
(P2) It follows from P1 that there will be times when we think we are awake and form beliefs about the world but in fact we aren't awake, and so those beliefs are actually false.
(C) Therefore, it is possible to doubt the truth of our beliefs about the external world.
Descartes brings up a possible counter argument: Lets suppose I am dreaming and in my dream I have purple octopus arms and the head of a dragon. Surely, this does not match up to the world as it is. However, all the perceptions of the basic constituent parts of my dream, like the color purple, the shapes, the textures, size, quantity, temporal duration and so on, all had to have come from somewhere. As he says:
[...] it surely must be admitted that the things seen during slumber are, as it were, like painted images, which could only have been produced in the likeness of true things, and that therefore at least these general things--eyes, head, hands, and the whole body--are not imaginary things, but are true and exist.
In short, you cannot imagine things ex nihilo (out of nothing); the original building blocks of your ideas have to originate from somewhere besides the inside of your head.
What follows from this? Here Descartes argues that because we are able to mix and match general and universal qualities in any manner of ways in our dreams and imagination (and sometimes we can't tell when we're dreaming) we must doubt truths that are about composite ideas. That is, ideas about things other than the fundamental properties of our thoughts. Some examples of things about which we can doubt are physics, astronomy, medicine (because they are about composite things).
So, what types of beliefs does the dream argument leave untouched? The answer is beliefs about disciplines that trade in a priori beliefs; that is beliefs about things we don't have to go out in the world to verify for truth. Arithmetic, geometry, for example, don't require for us to go out into the world to verify the truth of their assertions.
For example, when I divide 100 by 25 and give the answer of 4, I don't need to go out and physically manipulate things into piles to verify this truth. So long as I correctly follow the rules of arithmetic, I'll have the right answer. Not only will I have the right answer, but I'll have the right answer whether I'm dreaming or not. That is, regardless of whether I'm dreaming, so long as I follow the rules of arithmetic, I'll have the correct answer.
The same applies for geometric proofs. A square will have 4 sides whether I'm dreaming or not. If it doesn't, then it's no longer a square--it's something else. The same also applies to the bachelor example...and all a priori knowledge.
Aside
In the next section there's a little digression where Descartes talks about the possibility that his creator, if he so chose, would be able to be deceive him even about algebraic and geometric facts (i.e., a priori beliefs). Then he remarks that the combination of the 2 arguments and the possibility the God could deceive him are not quite enough to break him of his habit of trusting his sensorily-derived and a priori beliefs. He finds himself slipping back into the habit of assenting to them because it's "much more consistent with reason to believe them than to deny them." The same applies to God as a willful deceiver.
To prevent himself from slipping back into his old ways and to help him stick to his project of trying to reject any belief that it is possible to doubt, he's going to need a stronger method.
Enter the demon argument...(cue ominous music)
The Demon Argument (Or the Matrix)
Here we are to imagine a powerful evil genius who has dedicated himself to deceiving us. Everything you experience has been constructed by the evil genius. Here's the modern equivalent of the argument
The idea is this: All of your thoughts are being fed to you by an evil genius or a computer program--take your pick. Supposing this scenario, what can we know, that is, what beliefs can we have that we can be 100% sure are true?
If you've read the 2nd meditation, then you know...
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