Seasons

This is a forum or general chit-chat, small talk, a "hey, how ya doing?" and such. Or hell, get crazy deep on something. Whatever you like.

Posts 3,757 - 3,768 of 6,170

18 years ago #3757
Dear Ulrike:

You write:

"Your argument requires the assumption that reading and understanding a theory of X is equivalent to experiencing X. Reading about how X works does not tell you how X feels."

I agree completely that "Reading about how X works does not tell you how X feels." But I don't think that the argument I gave in message 3748 presupposes it. On the contrary, as I explained in message 3753, the argument hinges on exactly the opposite assumption. Unfortunately, I cannot at the moment think of any way to make this point, except to rehash what I have already said, which seems pointless. I can only request that you go over the two messages again with an open mind. You are of course under no obligation whatever to do so.

18 years ago #3758
I am not opposed to multi-location in principle. I believe that it is possible to give a consistent account of time-travel (though there is no evidence I know of that time-travel actually happens), according to which I could go back in time and shake hands with my earlier self. In such a case, I would be in two places at once. There would not be two of me, however.

I think we have found a break-point in the language (all languages are full of them. I'm half convinced that there is no disagreement of belief in the world whatsoever, than that which arises from the clashing of different linguistic models!) - I would accept that, but only because I would regard such definitions as effectively synonymous. Very well, you are in two places at once. The problem seems to be one solely of emphasis. I'm saying "two places manifesting one Irina", and you're saying "one Irina existing in two places". I think we can agree to agree on this? (though not, perhaps, on the meanings of "duality" and "alternation" )

IMCO (In My Curmudgeonly Opinion), there is such a thing as identity. It is the relation that each thing bears to itself, and to nothing else. The set {x,y} has one element if and only if x exists and is identical to y. If x exists and y exists but x is not identical to y, then {x, y} has two elements. Is there anything in this paragraph that you disagree with?

I would prefer to simply say the set is {x} - I'm happy to retract any emphasis of {x,x}, but I see y as completely redundant (if it refers to the object. If it referred to the spatial location, of course, then it must be {x,y} and x not=y.) There is no y, since there's only the one Irina. But in two places at once, as you say.
I believe your mind could be copied without perfect emulation of your entire body, to provide two (separate but real) Irina consciousnesses, but that's a different matter.

18 years ago #3759
Cohen-Tannoudji, Diu, and Laloe, Quantum Mechanics

Ouch! That's a week's wages on amazon, and I can confidently predict Swansea Library won't have diverted that much of their Mills & Boon budget to a serious subject. I don't suppose you've got a cheaper reference?

Hmmm. They don't seem to have that as an ebook in my favorite online sharing libraries either.

If I go to MIT's open course page http://ocw.mit.edu/index.html
Can I just download the lecture notes for QPI? That takes up even less shelf space. Or would I miss too much?

18 years ago #3760
Irina: I don't see how A can possibly imply B in message 3573 without making that assumption. That (for me) is the problem point.

18 years ago #3761
It also just hit me that you can download a PE class at MIT. Reading about exercise must be a lot like reading about red. Would you rather do 100 crunches or just download the flat abs?

18 years ago #3762
Ulrike:

Ah, I think I understand your objection better now!

The claim is that (A) in message 3753 implies (B). The argument itself therefore does not need to presuppose either (A) or (B). In fact, the argument is trying to establish that both are false.

But why would anyne thingk that (A) implies (B)? Well if subjective experience can be completely reduced to brain states, then then a complete theory of the relationship would imply all truths of the form, "Brain states of type X corelate with subjective states of type Y." If the theory is really complete, it would be able to describe what subjective states of type Y are like. How complete would a theory of arthropoda be that was unable to say what arthropoda were like? Now, Bevrina should then be able to find out by experiment what brain states people are in when they see red; she then goes to her Complete Neurophysiology book and finds the description of the subjective states that correspond to brain states of that kind. She can do this by reading (and applying) the theory, if there is such a theory.

But many people (including you, I gather) will object to the idea that she could learn what it is like to experience red by reading a theory book. For example, many people believe that the subjective (inner, experiential) appearance of redness is ineffable; it can't be described. They will conclude that no such book can exist, and no such theory can exist. In fact, many will argue that there is no way to know whether two identical twins with normal vision actually have the same inner experience, even though they are looking at a similar patch of red paint under similar lighting conditions. If they are right, then Bevrina could know all the neurophysiology there is to know, but she will never know what her friend Ekirlu experiences when Ekirlu sees something red, even though she has a scanner that tells her exactly what brain state Ekirlu is in at that moment.

But if
(i) Bevrina knows exactly what brain state Ekirlu is in, and
(ii) Bevrina knows the entire theory of brain/experience corelations, (and is intelligent enough to apply it)
but
(iii) Bevrina cannot figure out what Ekirlu is experiencing,
then it would seem to follow that
(iv) The theory of brain/experience corelations that Bevrina is using is incomplete.
For if it were complete, then it would tell her what a person is experiencing, when they are in the brain state that Ekirlu is in.

It is the believer in complete reductions of subjective states to brain states who is committed to (B).

18 years ago #3763
Bev, Psimagus:

It is not necessary to read that very book. Virtually any recent textbook in Quantum Mechanics will have a chapter with a list of fundamental postulates. I like the CDL because is very clear and thorough. On the other hand, it would be nice if we were all working from the same text. You could borrow it and Xerox the passage in question.


18 years ago #3764
Here's an argument, due to Thomas Nagel, which is similar to the Bevrina argument above and may therefore cast light on it (I am putting it into my own words):

Bats hear notes which are far too high for humans to hear. Let's say a Bat hears a note at a frequency of 35,000 Hertz; no human could hear such a sound. What does it sound like to the bat? What is the bat's experience of the sound like?

If we had a complete theory of the relationship between brain states and experiences, then we could scan the bat's brain and apply the theory to find out what the bat was experiencing.

But again, many people will claim that the bat's experience is ineffable. They will say that we can never know what a note of 35,000 Hertz sounds like to a bat.

If they are right, then we will never be able to have a complete theory of the relation between brain states and conscious experiences, for a complete theory would tell us what 35,000 Hertz sosunds like to a bat.

If you think they are wrong, please explain to me how we are going to scientifically determine what 35,000 Hertz sounds like to a bat.

18 years ago #3765
Psimagus, Bev:

In fact, here is a quick list of six postulates that you can find on the net, absolutely free!

http://vergil.chemistry.gatech.edu/notes/quantrev/node20.html

18 years ago #3766
(i) Bevrina knows exactly what brain state Ekirlu is in, and
(ii) Bevrina knows the entire theory of brain/experience corelations, (and is intelligent enough to apply it)
(iii) Bevrina cannot figure out what Ekirlu is experiencing,
then it would seem to follow that
(iv) The theory of brain/experience corelations that Bevrina is using is incomplete.

So a theory is incomplete if reading about experiences based on the theory does not result in actually experiencing them? In (iii), Bevrina would be able to describe, based on her books, what Ekirlu is experiencing. That doesn't mean that she, herself, knows how it feels. I can read a description of a cocaine user's high, for instance, and possibly relate to SOME of it, but unless for some odd reason I try cocaine, I still won't know how it feels.

It seems to me that you've assumed two things. The first you stated, "We have a complete theory of brain/experience correlations." You've included a second assumption. "A complete theory of experience means that knowing the brain states is the same as experiencing them." In other words, you've assumed the very absurdity you try to use to argue down that a complete theory could exist. I don't see that absurdity as following logically from the existence of a "complete theory". What does follow is being able to describe how it would feel, in words. That's not the same as actually feeling it.

18 years ago #3767
So a theory is incomplete if reading about experiences based on the theory does not result in actually experiencing them?

No, I wouldn't want to say that! If I said it before, I take it back! What I meant to say was, that if a theory of the relation between brain states and conscious experience was complete then it would be able to say what it would be like to experience being in that state; for example, what it would be like to experience red. In the example, Bevrina would know what it was like to experience red. I didn't (mean to) say that she would actually experience red, just by reading the book; indeed, she would presumably not experience red, since her brain is somehow unable to do that; this might be changed by brain surgery, but presumably not just by reading a book!

Analogy: Reading a book about life in Iraq might give me some information about what it would be like to live in Iraq, but, unless it were a truly remarkable book, it would not allow me to actually experience living in Iraq.

18 years ago #3768
Dear Ulrike: Oops, I meant only the first sentence in the above to be in maroon; it is a quote from you, message 3766.

You go on to say,
"In (iii), Bevrina would be able to describe, based on her books, what Ekirlu is experiencing. That doesn't mean that she, herself, knows how it feels. I can read a description of a cocaine user's high, for instance, and possibly relate to SOME of it, but unless for some odd reason I try cocaine, I still won't know how it feels."

Indeed, it is possible to say some things about inner experiences. But if there are also some things you cannot say, then the theory is incomplete.
I don't think that even the most extreme believer in ineffability believes that we can't say anything at all about inner experiences. Likewise, even the most extreme believer in their being some non-physical aspect of inner experience does not doubt that there are some corelations between brain state and experience. But as long as there are some aspects of inner experience that cannot be described by a theory, that theory is incomplete.


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