The Problem of Other Minds

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  • #1
confutatis
OK, maybe it was too difficult. Here's another approach:

A man can appear to be blind because he does not have visual experience. He appears to be blind because he is really blind.

A man can appear to be blind because he is lying about the fact that he is not blind. He is not really blind.

A man can appear to be blind because he is not capable of understanding his visual experiences. He is not really blind but doesn't know it.

Given the above, we have tautologically defined "real blindness" as "lack of visual experience".

This is not just a semantic game. Because our definition is tautological, everything that is true about "real blindness" is also true about "lack of visual experience".

It is true that really blind people cannot lie about the fact that they are really blind.

It is not true that people who are not really blind can lie about the fact that they are not really blind.

Therefore:

The belief that someone can be really blind and lie about that fact is based on a false notion

A corollary:

If a man behaves as if he's not blind, then we have no basis to believe in the possibility that he doesn't have visual experience

Come on, where is the "we have no way to know if other people have experiences" crowd?
 
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Answers and Replies

  • #2
confutatis
OK, maybe it was too difficult. Here's another approach:

A man can appear to be blind because he does not have visual experience. He appears to be blind because he is really blind.

A man can appear to be blind because he is lying about the fact that he is not blind. He is not really blind.

A man can appear to be blind because he is not capable of understanding his visual experiences. He is not really blind but doesn't know it.

Given the above, we have tautologically defined "real blindness" as "lack of visual experience".

This is not just a semantic game. Because our definition is tautological, everything that is true about "real blindness" is also true about "lack of visual experience".

It is true that really blind people cannot lie about the fact that they are really blind.

It is not true that people who are not really blind can lie about the fact that they are not really blind.

Therefore:

The belief that someone can be really blind and lie about that fact is based on a false notion

A corollary:

If a man behaves as if he's not blind, then we have no basis to believe that he doesn't have visual experience

Come on, where is the "we have no way to know if other people have experiences" crowd?
 
  • #3
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confutatis said:
It is true that really blind people cannot lie about the fact that they are really blind.
Explain why you say this. You do not state your reasons for saying this, you just claim it is the case. I'm not saying I will necessarily disagree with it. I just want to know why you think it's the case.

It is not true that people who are not really blind can lie about the fact that they are not really blind.
Again, please explain why you say this. This particular statement contradicts one of the conditions that you stated at the beginning of the posts.

Therefore:

The belief that someone can be really blind and lie about that fact is based on a false notion

A corollary:

If a man behaves as if he's not blind, then we have no basis to believe that he doesn't have visual experience
This conclusion is not saying anything different than the previous statements. In essence your conclusion is built into your premises. This is why I have asked you to explain your reasoning for the earlier statements.

Also, let me just ask that you not get too hung up on "vision" as a full representation of subjective experience. I'm convinced that you would have a much harder time selecting someone who cannot taste out of a crowd. To fake taste all one has to do is say "MMMMMmmmmm".

Come on, where is the "we have no way to know if other people have experiences" crowd?
You might want to give people a little more than a day to respond. Sometimes people get busy.
 
  • #4
hypnagogue
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confutatis said:
It is true that really blind people cannot lie about the fact that they are really blind.

It is not true that people who are not really blind can lie about the fact that they are not really blind.
What do you mean 'can lie'? Do you mean 'can convincingly appear as if'? (I assume you must, since a blind person can always say "I am not blind," although his behavior might indicate otherwise.)

If so, then I agree with your first proposition but not your second. Why can't a person who is not blind convincingly appear as if he is blind? This certainly does not follow from your first premise. You even seem to contradict this premise earlier in your post:

A man can appear to be blind because he is lying about the fact that he is not blind. He is not really blind.
 
  • #5
confutatis
Fliption said:
Explain why you say this. You do not state your reasons for saying this, you just claim it is the case.
I'm not claiming it to be the case, I'm just providing a definition and examining its logical consequences. That's the beauty of logical arguments, it makes no difference why we say what we say so long as we do not end up with contradictions.

This particular statement contradicts one of the conditions that you stated at the beginning of the posts.
See next note to hypnagogue.

Fliption said:
This conclusion is not saying anything different than the previous statements. In essence your conclusion is built into your premises. This is why I have asked you to explain your reasoning for the earlier statements.
So you do agree that the conclusion is built into the premises. That's what really matters.

My point is that you can't define "visual experience" in a way that the conclusion "it's impossible to know if other people have visual experiences" follows from the premises. You don't have to use my particular set of definitions, you can try others for yourself. But I doubt you will succeed to find any definition of visual experience which allows you to conclude that you have no way to know if other people have it.

Also, let me just ask that you not get too hung up on "vision" as a full representation of subjective experience.
Please don't take this wrong, but the quote above betrays some lack of familiarity with logic. All chains of logic are true regardless of what each member of the chain means. That's what makes logic so powerful - it allows us to gather facts about things we don't understand.

I'm convinced that you would have a much harder time selecting someone who cannot taste out of a crowd. To fake taste all one has to do is say "MMMMMmmmmm".
The very fact that you know there are people who cannot taste implies there's a way to know about it. Saying "mmmmmm" is not enough to fake taste, just as saying "I'm not guilty" is not enough to get someone out of prison. Come on, even detectives and lawyers know this stuff, it's pretty basic.

You might want to give people a little more than a day to respond. Sometimes people get busy.
I was afraid the reasoning was too abstract as stated in the first post.
 
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  • #6
hypnagogue
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Another contradiction.

confutatis said:
My point is that you can't define "visual experience" is a way that the conclusion "it's impossible to know if other people have visual experiences" does not follow from the premises.
More simply stated:
No matter how we define "visual experience," it must follow that it's impossible to know if others have visual experiences.

But I doubt you will succeed to find any definition of visual experience which allows you to conclude that you have no way to know if other people have it.
More simply stated:
No matter how we define "visual experience," it must follow that it's possible to know if others have visual experience.
 
  • #7
confutatis
hypnagogue said:
What do you mean 'can lie'? Do you mean 'can convincingly appear as if'? (I assume you must, since a blind person can always say "I am not blind," although his behavior might indicate otherwise.)
That's exactly what I meant.

If so, then I agree with your first proposition but not your second. Why can't a person who is not blind convincingly appear as if he is blind?
Well, that's the moot point I mentioned in the first post. You may consider the set of "people who are not blind but convincingly appear as if they are" to be an empty set. It doesn't change the argument a bit. In fact I just added that because I knew someone could ask the opposite question: "why can't a person appear to be blind simply because they are faking it", or something like that. It is a moot point, but I thought I had to show it explicitly.

Besides, if you think a person who is not blind cannot convincingly appear as if he is blind, then you are also saying that it takes real blindness for people to act as if they were blind. And that makes "real blindness" the exact equivalent of its behavioural counterparts. There is no difference between the two, and any claim to the contrary is based on nothing of any substance.

This [a man can appear to be blind because he is lying about the fact that he is not blind. He is not really blind] certainly does not follow from your first premise. You even seem to contradict this premise earlier in your post
Nope. I have defined the first case as "really blind", the second case as "not really blind". There's no contradiction as far as I can tell. But again, that's just added complexity to make sure I'm convering all possible objections.

What I really wanted to see addressed is the question, what basis do we have to believe that people who act as if they have visual experiences may not have them? You said I couldn't answer a question so many people have tried and failed, I'm saying they failed because the question is nonsense. But the nonsense is far from obvious, otherwise people would have spotted it a long time ago, and the entire history of Western philosophy would have been quite different.

The true voyage of discovery consists not in seeking new landscapes but in seeing with new eyes
Exactly!
 
  • #8
confutatis
hypnagogue said:
Another contradiction.
Sorry, that was a typo. I corrected the post; here's the excerpt:

My point is that you can't define "visual experience" in a way that the conclusion "it's impossible to know if other people have visual experiences" follows from the premises.

What I meant was that the conclusion doesn't logically follow from the premises. Sorry about the typo.

More simply stated:
No matter how we define "visual experience," it must follow that it's possible to know if others have visual experience.
So where's the problem of other minds? Where is the logic in saying it's not possible to know if others have visual experience?
 
  • #9
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confutatis said:
Well, that's the moot point I mentioned in the first post. You may consider the set of "people who are not blind but convincingly appear as if they are" to be an empty set.
The issue is whether a person who can see can, in principle, convincingly appear as if blind. This is a separate issue from whether or not people who can see actually do this in practice. There are principled reasons why a blind person cannot possibly behave as if he can see. There are no such principled reasons the other way; it is not impossible in principle that a person who can see, with proper insight and motivation, can behave such that he convincingly appears as if blind.
 
  • #10
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confutatis said:
I'm not claiming it to be the case, I'm just providing a definition and examining its logical consequences. That's the beauty of logical arguments, it makes no difference why we say what we say so long as we do not end up with contradictions.
I'm not talking about the conclusion. I understand that a conclusion follows form the premises. What I'm asking about is the premises themselves.

The first one: A real blind man cannot fake it and pretend he has visual experience

The second one: A non-blind man cannot fake it and pretend he doesn't have visual experience.

These were your premises. They aren't concluded from anything. I'm asking you why you are asserting them. I'm just looking for your reasoning. The first one I can probably buy but the second just seems plain wrong.

So you do agree that the conclusion is built into the premises. That's what really matters.
A conclusion is supposed to follow from the premises. Your conclusion is your premises. This is not a logical argument. It is simply a statement of believe.

My point is that you can't define "visual experience" in a way that the conclusion "it's impossible to know if other people have visual experiences"
follows from the premises. You don't have to use my particular set of definitions, you can try others for yourself. But I doubt you will succeed to find any definition of visual experience which allows you to conclude that you have no way to know if other people have it.
I don't know about you but I can't tell if you're blind or not. You haven't explained to me how I possibly could know that you aren't blind if you wanted to put on an act and stumble around the room a bit. I'm trying to understand your reasoning for making such a statement.

Please don't take this wrong, but the quote above betrays some lack of familiarity with logic. All chains of logic are true regardless of what each member of the chain means. That's what makes logic so powerful - it allows us to gather facts about things we don't understand.
In all seriousness, I do believe there is some lack of familiarity with logic here. But it isn't where you think it is. I'm not talking about your logical argument. I'm talking about your assumptions! Your premises! These are what you start with before the logical chain even gets started. I suggested that these premises don't hold at all with another example of subjective experience. And since your conclusion is just a re-statement of your premises, then it too isn't meaningful in these circumstances either.

The very fact that you know there are people who cannot taste implies there's a way to know about it.
But I don't know it. That's the point. Anyone can fake it. I have no idea whether anyone on this planet is able to taste or not.

Saying "mmmmmm" is not enough to fake taste, just as saying "I'm not guilty" is not enough to get someone out of prison. Come on, even detectives and lawyers know this stuff, it's pretty basic.
Huh? Exactlly what sort of evidence would a detective or a court of law use to conclude that I don't really have taste? I assure you, there is no such evidence.
 
  • #11
confutatis
hypnagogue said:
The issue is whether a person who can see can, in principle, convincingly appear as if blind.
That is not the issue I'm talking about.

This is a separate issue from whether or not people who can see actually do this in practice.
I don't know why you are dwelling on this point. It makes no difference whatsoever. I'm talking about two sets:

Set A: "all people who have visual experience"
Set B: "all people who don't have visual experience"

You're trying to discuss whether it's possible to know whether one of the sets may be empty, can be empty in principle, is actually empty... but that has nothing to do with what I'm talking about.

All I want to know is, if I know for sure that I am a member of set A, is there a way to know for sure who else is also a member of set A?

How exactly do you solve a problem like that? Forget about "experience", "blindness", "behaviour", and focus on a logical solution to an abstract problem. If you claim to know for sure you are a member of set A, what basis do you have to claim that you have no way to know to which set a member belongs?

The key point is not how you know who belongs to which set, the point is who gave you the notion that you may have something nobody else has? It couldn't possibly be other people, for they don't have it. So the notion that you may have something nobody else has is a fantasy not grounded on anything real. It's not to be taken seriously, or so it appears to me.
 
  • #12
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confutatis said:
Set A: "all people who have visual experience"
Set B: "all people who don't have visual experience"

...

All I want to know is, if I know for sure that I am a member of set A, is there a way to know for sure who else is also a member of set A?
There is no way to know for sure. This does not limit us from make good guesses. Based on how I have come to learn and use language, I find that in the vast majority (if not all) of cases, the times when it is appropriate for me to say e.g. "that thing is red" are precisely the times where I have a visual experience of redness. (If I am a child learning language and I look at a clear spring sky in the afternoon and say "red!" my mother will correct me, saying "no, that's blue.") It is a reasonable assumption then to assume that other people who can systematically refer to redness in response to the environment in the same way I can are also experiencing visual redness. But it still has the status of an assumption, because I cannot literally grab the redness from their minds, place it in my own mind, and say "yup, that is the same thing I was talking about after all."

In everyday life this limitation is not particularly important, but it is important when we are trying to create a theoretical framework of consciousness.

How exactly do you solve a problem like that? Forget about "experience", "blindness", "behaviour", and focus on a logical solution to an abstract problem. If you claim to know for sure you are a member of set A, what basis do you have to claim that you have no way to know to which set a member belongs?
The logic of the situation depends crucially on experience and behavior. These things provide the premises, the given pieces of information, from which we then logically deduce conclusions. I claim to know for certain I am a member of set A on the basis of my own visual experience, which has axiomatic status in our system of logic here. Also of axiomatic status is that I cannot literally see through other people's eyes and verify their own experiences for myself.

The key point is not how you know who belongs to which set, the point is who gave you the notion that you may have something nobody else has? It couldn't possibly be other people, for they don't have it. So the notion that you may have something nobody else has is a fantasy not grounded on anything real. It's not to be taken seriously, or so it appears to me.
Fact 1: If I look at a stop sign, part of my visual experience includes the experience of redness.

Fact 2: If I look at someone else who is looking at a stop sign, I cannot see whether or not they are having a red experience in the same direct sense that I could see redness as in fact 1.

Conclusion: I cannot be sure whether or not the person looking at the stop sign undergoes the same visual experience that I do when I look at the stop sign.
 
  • #13
confutatis
hypnagogue said:
There is no way to know for sure.
Why?

Based on how I have come to learn and use language, I find that in the vast majority (if not all) of cases, the times when it is appropriate for me to say e.g. "that thing is red" are precisely the times where I have a visual experience of redness. (If I am a child learning language and I look at a clear spring sky in the afternoon and say "red!" my mother will correct me, saying "no, that's blue.") It is a reasonable assumption then to assume that other people who can systematically refer to redness in response to the environment in the same way I can are also experiencing visual redness. But it still has the status of an assumption, because I cannot literally grab the redness from their minds, place it in my own mind, and say "yup, that is the same thing I was talking about after all."
What if you could grab the "redness" from other people's minds and find out that no two people see red the same way? Would that change the meaning of the word 'red'? What should we call it now? 'Green' according to John, 'Blue' according to George, 'Violet' according to Paul?

To me the answer is a clear and emphatic NO. The meaning of the word 'red' has nothing to do with your visual experience of it. I am absolutely sure you see this color as red, and I don't need to look at your mind to know that. That is because the meaning of the word 'red' has nothing to do with your subjective experience.

In everyday life this limitation is not particularly important, but it is important when we are trying to create a theoretical framework of consciousness.
In everyday life this limitation is completely irrelevant, except perhaps to explain why different people prefer different colors. Maybe we all like the same colors?

I claim to know for certain I am a member of set A on the basis of my own visual experience
No, you claim to know for certain you are a member of set A on the basis of what people tell you you need to have in order to be a member of set A. You're not claiming you are born knowing what the word 'experience' means, are you? And if you have learned the meaning of the word 'experience' from other people, how can you possibly think those people don't know what 'experience' means? Can't you see the nonsense?

Also of axiomatic status is that I cannot literally see through other people's eyes and verify their own experiences for myself.
But it is not axiomatic that you cannot know what they know. That is nonsense. If I ask you which alias I use on this forum and you say 'confutatis', what basis do I have to claim you may not know what my alias is? How else could you possibly write 'confutatis'? Mere chance? Come on.

Fact 1: If I look at a stop sign, part of my visual experience includes the experience of redness.

Fact 2: If I look at someone else who is looking at a stop sign, I cannot see whether or not they are having a red experience in the same direct sense that I could see redness as in fact 1.
The part of your experience which includes any aspect that cannot possibly be known by anybody else does not concern anybody else. Why should you bother which way I see red if that information adds absolutely nothing to your knowledge of anything?

Conclusion: I cannot be sure whether or not the person looking at the stop sign undergoes the same visual experience that I do when I look at the stop sign.
If you claim different people see the world in different ways, what's preventing you from also claiming that vision reveals nothing about the world? Surely if I see a stop sign as red and you see it as yellow, then it is neither red nor yellow. It doesn't even have color. As a consequence, it doesn't also have size, shape, position, mass, relative speed... suddenly our picture of reality ceases to be real, and we're left with abstractions as the only things that exist. And if abstractions are the only things that exist, then there's nothing about reality that cannot be expressed through language.

Your premises end up falsifying themselves, but you don't see that because you won't go all the way, you stop in the middle.

That's how I see it anyway.
 
  • #14
confutatis
(this coffee-break philosophy business can be tough...)

Fliption said:
I have no idea whether anyone on this planet is able to taste or not.
That is nonsense and I will show you why. Blindfold someone and give them two cups of drink, one with lemon juice, one with water. Ask them to drink from both cups and tell you which cup contains lemon juice. If they get it right, that means they are able to taste.

But more important, you may have been born with the ability to tell the difference between your experience of drinking lemon juice and your experience of drinking water, but you cannot possibly claim you were born with the knowledge that the thing that gives you the experience of drinking lemon juice is called 'lemon juice'. You must have learned that from other people, no question about that.

Now you believe in the hypothesis that you may be the only person with a sense of taste in the whole world. Surely it's a remote hypothesis, but since it's not ruled out by logic it's a real hypothesis. However, there is a way to rule it out by logic: if nobody else had a sense of taste, they would never be able to come up with words such as 'sweet', 'sour', 'bitter', or to say that something 'tastes like lemon juice', for the simple reason that they could not apply those words in a consistent way. They would keep disagreeing as to whether something tastes like honey or like brocolli. As a result of that, you would never know what honey and brocolli taste like, for the simple reason you would be completely unable to know what people mean when they use those words.

You can't communicate with people who don't understand what you are talking about. That is a fact. Contradicting that fact is bad usage of precious intellectual resources.
 
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  • #15
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confutatis said:
What if you could grab the "redness" from other people's minds and find out that no two people see red the same way? Would that change the meaning of the word 'red'? What should we call it now? 'Green' according to John, 'Blue' according to George, 'Violet' according to Paul?

To me the answer is a clear and emphatic NO. The meaning of the word 'red' has nothing to do with your visual experience of it. I am absolutely sure you see this color as red, and I don't need to look at your mind to know that. That is because the meaning of the word 'red' has nothing to do with your subjective experience.
I would agree in one sense. You do know, trivially, that this color looks 'red' to me. This is because the basis for my experience of redness ultimately falls back to a source that is shared between us in the external world. In this sense "red" means "light with a wavelength of roughly 600 nm."

Now, here is the thing. The word "red" can be used consistently across people precisely because in the objective, functional sense, red ultimately refers to a common source-- it is always caused by (or always correlated with, whatever) light of wavelength 600nm. But I contend that the way I use the word red, conceptually, does not refer directly to light of wavelength 600nm. It refers to my visual experience of that color that I call red, which is conceptually distinct from objective light wavelengths, even if we can traverse the causal chain backwards far enough that eventually we reach a description on the level of objective photons.

If you accept even the most basic of covarying relations between brain and mind (which you are basically forced to do by findings in neuroscience), I can state this more concretely. Say there is some neural process N1 such that it is univerally responsible for producing (being correlated with, whatever) the subjective visual experience of this color, and likewise N2 is universally associated with this color. Say Bob's brain is wired such that 600nm light striking his retina always activates N1 in his brain, and Jane's brain is wired such that 600nm light always activates N2 in her brain. Now, whenever Bob and Jane both see 600nm light, they will both say "I see red." But are they referring to light in this very objective sense of 'photons with a wavelength of 600nm'? No, that is impossible. They must be referring to the portion of their brain that registers and interprets such light. So in a very direct sense, Bob's "red" refers to N1 and Jane's "red" refers to N2. Accordingly, Bob's "red" refers to subjective experience of this color while Jane's "red" refers to this color.

In this case, Bob and Jane can act as if there is no difference in their visual experiences and get along just fine, because the source of their perceptions is the same-- they are both 'coding for' the same objective thing. On closer inspection, however, we find there is an internal distinction to be made-- although they are coding for the same thing, they code it in different ways. This makes no practical difference in terms of relating to the external world, but at the same time there is obviously an ontological difference with respect to their internal models of that external world.

No, you claim to know for certain you are a member of set A on the basis of what people tell you you need to have in order to be a member of set A. You're not claiming you are born knowing what the word 'experience' means, are you? And if you have learned the meaning of the word 'experience' from other people, how can you possibly think those people don't know what 'experience' means? Can't you see the nonsense?
You are right to point out that this is a sticky issue, but it is not debilitating. If I am brought up from infancy by a zombie, then it is true that my zombie parent does not know what 'experience' really means. At the same time, however, by way of sheer internal consistency, I do come to know what experience means-- I come to systematically associate the word with my own subjective experiences.

Now, again, the question arises to what extent I know that the way I use the word is the same as the way others use it. Problematic, perhaps, but as long as I make some rational observations (I learn principles of causality, see that other people by and large have the same internal makeup as I do, and so on) to make some reasonable assumptions (others with normally functioning brains and similar physical and verbal behavior as I have have experiences in roughly the same sense I do), I am back on relatively firm footing. There always remains some doubt, but it isn't unique to this epistemic endeavour. Scientists assume principles of induction all the time without any absolutely certain knowledge-- there is no way to be absolutely sure that tomorrow the laws of gravitation will suddenly cease to function and the earth will spin off into the void. But still, we can get by even if we leave some room for epistemic doubt, so long as our assumptions are well reasoned and appear to be largely consistent with what observations we can make.

But it is not axiomatic that you cannot know what they know. That is nonsense. If I ask you which alias I use on this forum and you say 'confutatis', what basis do I have to claim you may not know what my alias is? How else could you possibly write 'confutatis'? Mere chance? Come on.
Your alias is identical to the string of letters that appears in the upper left corner of each of your posts, by definition, so I can trivially have certain knowledge in this case. On the other hand, one's own behavior and language are readily demonstrated, from one's own 1st person view, not to be identical to subjective experience, even if the two are intricately related.

The part of your experience which includes any aspect that cannot possibly be known by anybody else does not concern anybody else. Why should you bother which way I see red if that information adds absolutely nothing to your knowledge of anything?
Perhaps it is of no practical use in everyday life, but it is invaluable to know any subjective differences between us if we are to formulate a comprehensive theory of consciousness.

If you claim different people see the world in different ways, what's preventing you from also claiming that vision reveals nothing about the world? Surely if I see a stop sign as red and you see it as yellow, then it is neither red nor yellow. It doesn't even have color. As a consequence, it doesn't also have size, shape, position, mass, relative speed...
The stop sign is not uniquely red or yellow in and of itself, but this should not be surprising since these things are functions of our separate brains interpreting the stop sign, not properties of the stop sign itself. The property that belongs to the stop sign itself is that it reflects light of 600nm wavelength, and this is consistent with both of our perceptions, so long as my 'red' and your 'yellow' are both precipitated by a causal chain beginning with 600nm light striking our retinas. The objective stop sign retains, in entirety, its objective characteristics. We are both coding for the same thing, even if we use slightly different coding strategies.
 
  • #16
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confutatis said:
(this coffee-break philosophy business can be tough...)
That is nonsense and I will show you why. Blindfold someone and give them two cups of drink, one with lemon juice, one with water. Ask them to drink from both cups and tell you which cup contains lemon juice. If they get it right, that means they are able to taste.
I can do the same trick with a piece of litmus paper. Are you suggesting that litmus paper is having subjective experience just because it can distinguish between water and lemon juice? So who's to say that whatever mechanical non-experiential process which allows the litmus paper to work isn't the same process being used by a persons tongue? No subjective experiences required?

Even without saying all that, I can claim that a person who can experience taste can still claim that they cannot and you would never know. They could drink both drinks and tell you they have no idea which one is lemon juice. How would you determine that they were lying?

There is a difference between the physics of your eye capturing light of a certain wavelength and your subjective experience of color. They are not the same things. One of them is easy to test for, the other is not possible. The above example of yours implies that you are confusing the two.

But more important, you may have been born with the ability to tell the difference between your experience of drinking lemon juice and your experience of drinking water, but you cannot possibly claim you were born with the knowledge that the thing that gives you the experience of drinking lemon juice is called 'lemon juice'. You must have learned that from other people, no question about that.
Again you seem to confuse the physics of making distinctions in the objective world with subjective experiences of them. A person can have a "litmus paper tongue" and learn to make the distinctions about the objective world. They can then learn and teach the language about those distinctions and still have zero subjective experiences.
 
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  • #17
confutatis
Fliption said:
I can do the same trick with a piece of litmus paper. Are you suggesting that litmus paper is having subjective experience just because it can distinguish between water and lemon juice?
This line of reasoning has no substance. I doubt you understand what "subjective experience" means in the context above. You are assuming the question of determining if paper can have subjective experience is a meaningful one. I see no rationale for that assumption, and I see no need to answer a question that has no clear meaning.

So who's to say that whatever mechanical non-experiential process which allows the litmus paper to work isn't the same process being used by a persons tongue? No subjective experiences required?
Given the above, this is a non-sequitur.

Even without saying all that, I can claim that a person who can experience taste can still claim that they cannot and you would never know. They could drink both drinks and tell you they have no idea which one is lemon juice. How would you determine that they were lying?
I suspect you haven't read my posts to hypnagogue. I made a typo when I said it's impossible to fake blindness. What I meant was that it is impossible to fake vision if you are blind.

There is a difference between the physics of your eye capturing light of a certain wavelength and your subjective experience of color.
Of course there's a difference, that's why blindness exists. We all know that, and it has nothing to do with the argument.

Again you seem to confuse the physics of making distinctions in the objective world with subjective experiences of them. A person can have a "litmus paper tongue" and learn to make the distinctions about the objective world. They can then learn and teach the language about those distinctions and still have zero subjective experiences.
Well, since you have everything a zombie has, plus something they don't, you can do everything they do, right? So go on and tell me how you would develop the ability to report information about your environment without having to rely on your subjective experience. What method can you follow to make your mouth and tongue move and say "I'm now tasting lemon juice", while your mind is totally empty of any experiences, or perhaps fantasizing about Caterina Zeta-Jones? After all, if zombies can do it (not the Zeta-Jones thing, but definitely the totally empty thing), then you should be able to do it too. Even better, since zombies can do that cheap trick without having to think about how to do it, then you should be able to do exactly the same thing, also without thinking. Unless you want to claim that thought actually gets in the way of doing things even a zombie can do.

By the way, I know you have no way to be sure, but for the purposes of replying please assume I'm not a zombie :cool:
 
  • #18
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confutatis said:
This line of reasoning has no substance. I doubt you understand what "subjective experience" means in the context above. You are assuming the question of determining if paper can have subjective experience is a meaningful one. I see no rationale for that assumption, and I see no need to answer a question that has no clear meaning.
I do not understand this response. Of course I am not suggesting that litmus paper has subjective experiences. I'm claiming that your view concludes this. If you go back to your 2 drinks example, you imply that the only reason I could know that someone can have the subjective experience of taste was if they could distinguish lemon juice from water. Clearly, this distinction can be made without subjective experience. Litmus paper being one example of how.

Let me suggest that part of the confusion may be when you say the word "taste". The physics of the tongue being able to detect differences between lemon juice and water can be completely explained. Is this what you call taste? Or is the subjective experience of these liquids (the mechanics of which cannot be explained at all) what you are calling taste? They are 2 different things. Yet you simply say "taste" seemingly wrapping the two into one concept (as you also did with the word "blindness"in your original post). The only thing you can know about someone who can tell you which glass contains lemon juice, is that the physics of their tongue is working. You can tell nothing about subjective experience.

I suspect you haven't read my posts to hypnagogue. I made a typo when I said it's impossible to fake blindness. What I meant was that it is impossible to fake vision if you are blind.
I have gone back and read this entire thread and many of your posts over and over again. It isn't easy but I think I am deciphering it.

But look at this quote above and read it carefully. Are you now saying that a person who is not blind can fake blindness? If so, then how does your conclusion that we can have knowledge of others subjective experiences hold?

Of course there's a difference, that's why blindness exists. We all know that, and it has nothing to do with the argument.
No that's not why blindness exists. Blindness does not exists because someone doesn't have subjective experiences. This skips a step. More to come below.


Well, since you have everything a zombie has, plus something they don't, you can do everything they do, right?
No. none of this follows. I don't have everything a zombie has. I don't have the ability to use the physics of my senses without triggering subjective experiences. A zombie does have this ability.

So go on and tell me how you would develop the ability to report information about your environment without having to rely on your subjective experience. What method can you follow to make your mouth and tongue move and say "I'm now tasting lemon juice", while your mind is totally empty of any experiences, or perhaps fantasizing about Caterina Zeta-Jones? After all, if zombies can do it (not the Zeta-Jones thing, but definitely the totally empty thing), then you should be able to do it too. Even better, since zombies can do that cheap trick without having to think about how to do it, then you should be able to do exactly the same thing, also without thinking. Unless you want to claim that thought actually gets in the way of doing things even a zombie can do.
No I cannot do it, because I am "wired" to have subjective experiences. But I can imagine in principle writing a program for and hardwiring a robot who can do all the things you mentioned. This robot would be a zombie by definition, but you would never know.

Again, the problem that I see with your position is that you are assuming that the physics the body executes to make it's distinctions is equivalent to the subjective experience. It is clear to me that they are linked, but no one can explain exactly how. So to assume they are one and the same is a big assumption. Your reply to this will probably be "But I don't think they are the same thing". As a matter of fact you've already said this here:

"Of course there's a difference, that's why blindness exists. We all know that, and it has nothing to do with the argument."

But it has everything to do with your argument. The entire problem is embedded in your very first post where you equate the two (or tie them directly together) by claiming:

1) A man can appear to be blind because he does not have visual experience. He appears to be blind because he is really blind.
2) A man can appear to be blind because he is lying about the fact that he is not blind. He is not really blind.
3) A man can appear to be blind because he is not capable of understanding his visual experiences. He is not really blind but doesn't know it.

In each case, you directly link the appearance of blindness to subjective experience. But this misses an important step, imo. I'm arguing that blindness is easily detected and does not need to be based on "appearances". "Appearances" is the nature of subjective experience, not blindess. Blindness is defined as someone who's eyes do not perform the necessary mechanics of processing visual data. A trip to the doctor can determine this easily.

So here's the link with the missing piece inserted:

Not blind > Eyes perform all functions of physics properly > Subjective experience

Blind > Eyes don't perform all functions of physics properly > No Subjective experience

The piece in the middle is what you have left out. Or rather, you have equated it to subjective experience. We can understand all about how the eye works and even determine whether it works by examining it. We know that there is a link between the eyes functioning and subjective experience but no one yet understands how this link happens.
The only thing that you can determine by handing me a glass of lemon juice is whether my tongue is functioning properly. You can't possibly conclude with certainty the subjective experience piece because no one yet understands how to find it in the link. You can only assume it ( as reasonble as it may seem to do so). It is not a necessary link as I've explained with the litmus paper, which can distinguish lemon juice from water without resulting in subjective experience. A camera can do the exact same thing. It is the same technology the eye uses but the camera does not have subjective experiences does it? So why would you conclude with certainty that I have subjective experiences simply because I can make the same distinctions that litmus paper and computers with cameras can make?
 
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  • #19
confutatis
hypnagogue said:
I would agree in one sense...
It's good we agree on something, even if very basic. Maybe I can get you to understand what I'm saying so you can properly criticize it. I have to be brief today so I'll focus on what I consider essential. The rest of your post can certainly spawn several threads on different subjects.

If I am brought up from infancy by a zombie, then it is true that my zombie parent does not know what 'experience' really means.
Actually, in a world of zombies the word 'experience' would never exist. How could a zombie come up with a word for something he does not know what it is, and yet be able to use that word to communicate with other zombies?

But it doesn't stop there. If you were the first non-zombie in the history of mankind, you too would never know what the word 'experience' means. Certainly you would not have learned it from zombies, for as I said above they couldn't have the word and use it in a consistent way that made it intelligible to you.

(I know this is complicated; sorry if I'm not being clear)

I suppose you can conceive of something I will call "zombieness". If a zombie is an entity which lacks experience but behaves as if it does, then it seems right to me to talk about "zombie behaviour" as being different from behaviour that is associated with subjective experience. So zombieness is behaviour which is dissociated from conscious experience. Now this is very interesting:

Can you have zombieness? It's certainly the case that some aspects of your behaviour cannot be accounted for by any subjective experience, right? We call this kind of behaviour "unconscious", correct? For instance, if an object is flying toward your eye, your eye will close before you have the subjective experience of seeing the danger. So to a good extent, we have something in common with those zombies.

Imagine now that people are different as to the extent to which they are afflicted by zombieness. Let me give you an example. Suppose all living things have something physical around them which not everyone can experience. Some people who claim to be able to experience that thing refer to it as, say, 'aura'. They talk about it amongst themselves and seem to be in agreement as to what 'aura' means as well as to its reality. But on the other hand most people are afflicted with 'aura-zombieness', and as such either do not understand what 'aura' means or do not agree with "non-aura-zombies" that it is real.

Now the really important point about the above is this: people who have 'aura-zombieness' only add the word 'aura' to their vocabulary because the 'non-aura-zombies' chose the word 'aura' to talk about an experience they have. 'aura-zombies' would never, ever come up with the word 'aura', because they had no way to use the word consistently.

The point is, the subjective experience which allows you to grasp the meaning of a word is exactly the same thing which makes the meaning of the word consistent across different speakers. We know that other people are conscious not because we must assume it, but because we conclude it from assumptions that are far more basic and important. You can't destroy the certainty about other people's mental states without destroying a lot of other certainties as well, including the certainties about your own mental states.

The mind is like an extremely poweful calculator. You input facts to it, it gives you back conclusions, but it doesn't tell you how it arrived at the conclusions. Commonsense is difficult to justify with logic not because commonsense is illogical, but because there are more variables than you can possibly handle on a conscious basis.
 
  • #20
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confutatis said:
I will give you a quick reply today because I'm busy with more important stuff. Hope you don't thinking I'm dismissing you, I see you put a lot of thought in your last post.
Truthfully, this post of yours irritated me. I can relate to having little time to post but I would prefer that if you aren't able to properly respond to the discussion then don't respond at all. Meaningless, insulting one liners aren't needed.

Your claim is based on your misunderstanding of my view. What my view implies is that if litmus paper has subjective experience, it's not the kind of subjective experience you can relate to. As such, the knowledge that litmus paper has, or does not have, subjective experience adds absolutely nothing to your understanding of anything.
I apologize. I just don't understand what you're talking about. Whether litmus paper has subjective experience or not really isn't the relevant point I'm trying to make. It is just an extreme that you're statement about lemon juice implies. The real point is about your statement, not litmus paper.

I didn't imply that. If I may offer a humble suggestion, you must be very, very careful when you try to figure out what an argument implies. Understanding an argument is hard enough; invalidating an argument you don't fully understand on the basis of what it seems to imply to you is a waste of time.
You didn't imply that?

Here's what you said:

"Blindfold someone and give them two cups of drink, one with lemon juice, one with water. Ask them to drink from both cups and tell you which cup contains lemon juice. If they get it right, that means they are able to taste."


I'm sorry but there is no other way for me to interpret this quote. It clearly means that if a person can distinguish lemon juice from water, then they have subjective experience. And I'm telling you that we can have a computer with a litmus paper input system do exactly the same thing that this blindfolded person has done. Of course, I'll concede that you don't actually say that the person is having "subjective experiences". You say they can "taste". But based on your conclusions I interpret your use of "taste" to mean subjective experience. I asked the clarifying question on your use of "taste" in my previous post but it didn't get answered.

So I got a lecture for ignorantly implying something when I'll be willing to take a poll in this forum and show that most people wouldn't imply any different.

This is nonsense. What physics really explains is why the subjective experience of taste is shared by many people. In other words, physics tells us that the subjective experience of taste is, to a large extent, based on objective facts.
No, physics says nothing about subjective experiences. How can you possibly solve the problems of philosophy when you don't understand them?

That made me laugh! So a zombie has everything you have - eyes, a tongue, a brain, neurotransmitters, everything - but a zombie has something you don't have, but it's not something physical either, after all you are the one who has the non-physical thing.

Come on, man, it's Friday, I don't have time for this nonsense :mad:
What is actually funny is that everyone else has deserted this thread and written you off as a crackpot except for me and hypnagogue. Mostly due to the fact that you think that only you have had the wisdom to figure out this gross error that centuries of western philsophy is based on. And you are laughing? Yep it's all very funny. :biggrin:

This zombie stuff is pure nonsense and isn't relevant to anything I am saying. It is a diversion. I would rather you have responded to the more important issues I presented.

So the ethereal, unspekable, innefable thing you call subjective experience is actually made of wires?

I think this should be enough to show you how problematic your thinking is. I have to get some work done now.
Huh? Now you're just being difficult and purposefully non-productive. My use of the word wired is a figure of speech. Which is why I placed quotes around it; So that it wouldn't be taken literally. So much for that. You have shown me nothing that makes me think my views are problematic.
 
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  • #21
confutatis
Fliption said:
Truthfully, this post of yours irritated me. I can relate to having little time to post but I would prefer that if you aren't able to properly respond to the discussion then don't respond at all.
Your wish has been granted. The post has been deleted.

Sorry for getting you so upset, it was not my intention. I thought we were having a friendly discussion.

I don't care for the crackpot stuff. You think I'm a crackpot because you think I'm saying something I'm not. All I'm saying is that I have no reason to believe anyone around me who appears to be conscious is not really conscious, only pretending to be. What you are saying is that when I share other people's joys and sufferings, there's a philosophical possibility that I'm being foolish, for they may not be experiencing anything at all.

But I am the crackpot, and those philosophers with unpronouceable German names are Great Thinkers. Well, if crackpot means I don't want to join their company, then I'm the proudest crackpot around!
 
  • #22
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confutatis said:
Actually, in a world of zombies the word 'experience' would never exist. How could a zombie come up with a word for something he does not know what it is, and yet be able to use that word to communicate with other zombies?
I understand this point as well. But this does not solve the problem of other minds. First of all this only implies that there needed to be more than one person capable of subjective experiences to develop a language with the word "experience". So it seems it might do away with solipsism. It says nothing about whether any specific person has subjective experiences. You stilll cannot prove that any one person has subjective experiences and this is what the problem of other minds is.

This problem of others minds is not just an issue of whether someone has subjective experiences or not. It also involves the fact that you cannot know what anyone else is experiencing. This problem, you have already acknowledged.

Try doing a search for this problem on the internet. Just so we can end the idea that you are the only one thinking of this, I'll end with a quote. This isn't the only one, the internet and philosophy texts are full of discussion on this.

The point Wittgenstein is trying to bring out is that, contrary to the philosophies of Cartesianism and traditional empiricism, the language we couch our mental statements in is a public language: the words we use only acquire their meaning through public usage. And thus if there were no other minds in the world other than our own, we could not make publicly understandable statements about our mental states. This is a powerful argument, although it is open to at least two criticisms.

Firstly, it is claimed by some philosophers that it leads inexorably to a form of behaviourism in which my knowledge of my own mental states through introspection is not accounted for. Secondly, the argument tells us very little about the content of other minds. What is the relation between words and mental states?, and more importantly, how could it conceivably be discovered? By appeal to our own case? That would just beg the question.
 
  • #23
hypnagogue
Staff Emeritus
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confutatis said:
All I'm saying is that I have no reason to believe anyone around me who appears to be conscious is not really conscious, only pretending to be. What you are saying is that when I share other people's joys and sufferings, there's a philosophical possibility that I'm being foolish, for they may not be experiencing anything at all.
If that is really your main objection, there is no reason the two can't live side by side. I take it for granted all the time that people around me are conscious, but this does not prevent me from acknowledging that this is only an inference, a good guess, that I cannot corroborate with absolute certainty.

By analogy, Einstein had an intuition that perhaps the speed of light in vacuum is constant regardless of one's reference frame. This was merely an intuition, or good guess, on his part insofar as he had an insight to apply the principle of frame invariance of physical laws to Maxwell's equations. Although Einstein's intuition was well motivated by reason, it could not be held with absolute certainty (or something close to it) until the constancy of light speed was verified experimentally.

We are in a similar situation as Einstein: I (you) have well motivated reasons to believe that others are conscious in the same way that I am (you are). However, the difference is that our intuition cannot be corroborated whereas Einstein's could, and was. To verify the constancy of light speed is to directly measure the speed of light in varying reference frames. To verify the consciousness of others would mean to have some way to directly observe the phenomenal contents of their consciousness. Unfortunately, while we have plenty of clocks and rulers to work with, we have no 'consciousness meter,' so our well motivated inferences must remain just that: inferences with no current means of empirical justification, that will perhaps never have any means of empirical justification. As a consequence, we must allow some room for philosophical uncertainty, even if this philosophical uncertainty has little bearing on the practical concerns of day to day life.
 
  • #24
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confutatis said:
Your wish has been granted. The post has been deleted.

Sorry for getting you so upset, it was not my intention. I thought we were having a friendly discussion.

I don't care for the crackpot stuff. You think I'm a crackpot because you think I'm saying something I'm not. All I'm saying is that I have no reason to believe anyone around me who appears to be conscious is not really conscious, only pretending to be. What you are saying is that when I share other people's joys and sufferings, there's a philosophical possibility that I'm being foolish, for they may not be experiencing anything at all.

But I am the crackpot, and those philosophers with unpronouceable German names are Great Thinkers. Well, if crackpot means I don't want to join their company, then I'm the proudest crackpot around!

This sounds like an appeal to common sense. As info, if I had to put money on it, I'd agree with you and say everyone is conscious and experiencing the same things that I am. But this isn't the point. Common sense doesn't work in philosophy (though it certainly has influenced the conclusions of many of those german thinkers you mentioned). The philosophical problems can't be proved with certainty, regardless of how convinced we all are that it is a certain way.

Also, I do not think you are a crackpot and didn't mean to imply that I thought that.
 
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  • #25
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hypnagogue said:
We are in a similar situation as Einstein: I (you) have well motivated reasons to believe that others are conscious in the same way that I am (you are). However, the difference is that our intuition cannot be corroborated whereas Einstein's could, and was. To verify the constancy of light speed is to directly measure the speed of light in varying reference frames. To verify the consciousness of others would mean to have some way to directly observe the phenomenal contents of their consciousness. Unfortunately, while we have plenty of clocks and rulers to work with, we have no 'consciousness meter,' so our well motivated inferences must remain just that: inferences with no current means of empirical justification, that will perhaps never have any means of empirical justification. As a consequence, we must allow some room for philosophical uncertainty, even if this philosophical uncertainty has little bearing on the practical concerns of day to day life.
As of late, I have been reading a lot of Michael Lockwood's work, and the problem I see now, is that consciousness in its form doesn't really formulate any algorithmic encodings of any mathematical consciousness explanation, or your coinage I liked "consciousness meter". Nonetheless, if it possible to measure the senario's of consciousness, then it is equally possible to say that they should have a computational formula to equate with brain subjectivity and awareness. The software for consciousness, paraphrased by Lockwood should have natural substrates in its "information-theoretic" data.

Now, anything physical isn't going to measure consciousness, as far as we know, so my question is: if reflections of human psychology can 'measure' consciousness, then why isn't physical processes compatible with physical actions? If the brain neurons signal functions, the physical action should give away the consciousness experience, shouldn't it? Now, how we define and measure this is the problem, but isn't that a formulation of how consciousness works in its form, agreed?

If the mind is organizational and humanly-constructed categories exist, then consciousness is and can be 'measured', right? Consciousness is epistemically possible; and the solution should be retrospectively obvious, shouldn't it, if physical interactions equate with mind data? Consciousness should be instrumental, in the sense its performed and done: the problem is figuring out how to play it, right?
 
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