moving finger said:
Not all human brains “implement semantics”.
A person in a coma is not “implementing any semantics” – a severely brain-damaged person may be conscious but may have impaired “implementation of semantics”.
Tournesol said:
That is a silly objection.
It is not an objection, it is an observation. Do you dispute it?
Tournesol said:
Anyone I can actually speak to obviously has a
functioning brain.
Tournesol, your arguments are becoming very sloppy.
I can (if I wish) “speak to” my table – does that mean my table has a functioning brain?
Tournesol said:
I am not going on their external behaviour alone; I have
an insight into how their behaviour is implemented, which is missing in the CR
and the TT.
What “insight” do you have which is somehow independent of observing their behaviour?
How would you know “by insight” that a person in a coma cannot understand you, unless you put it to the test?
How would you know “by insight” that a 3-year old child cannot understand you, unless you put it to the test?
moving finger said:
The solution to this problem is to try and develop a better test, not to “define our way out of the problem”
Tournesol said:
I have already suggested a better test. You were not very receptive.
Sorry, I missed that one. Where was it?
Tournesol said:
It would help if you spelt out what, IYO, the (strong) AI arguemnt does say.
I am not here to defend the AI argument, strong or otherwise.
I am here to support my own position, which is that machines are in principle capable of possessing understanding, both syntactic and semantic.
Tournesol said:
you seem to be assuming that there is some set of
rules that are sufficient for semantics.
Agreed
Tournesol said:
let us call the thesis
you are promoting
"The Symbol Manipulation According to Rules Technique is sufficient for semantics thesis"
w is
or
"The SMART is sufficient for semantics thesis"
Where SMART is any kind of Symbol Manipulation According to Rules.
Not “any kind” of symbol manipulation – a particular symbol manipulation
Tournesol said:
Note, that this distinction makes no real difference to the CR.
Can you show this, or are you simply asserting it?
Tournesol said:
Searle uses "syntax" and "symbol manipulation" interchangably because it
does not strike him that semantics is or could be entirely rule-based.
That’s his opinion. I do not agree
Tournesol said:
In fact,
it as never struck anybody except yourslef, since there are so many objections
to it.
I do not think this is true. Even if it were true, what relevance does this have to the argument?
moving finger said:
The semantic knowledge and understanding is “encoded in the information in my brain” – I do not need continued contact with the outside world in order to continue understanding, syntactically or semantically.
Tournesol said:
How is that relevant to the CR ? Are you saying that the CR can *acquire*
semantics despite its lack of interaction and sensory contact with an
evironment ?
I am saying that the information and knowledge to understand semantics can be encoded into the CR, and once encoded it does not need continued contact with the outside world in order to understand
Tournesol said:
Are you saying you can "download" the relevant information
from a human -- although you have already conceded that information may
fail to make sense when transplanted from one context to anothera ?
Where did I say that the information needs to be downloaded from a human?
Are you perhaps suggesting that semantic understanding can only be transferred from a human?
The only “information” which I claim would fail to make sense when transplanted from one agent to another is subjective experiential information – which as you know by now is not necessary for semantic understanding.
Tournesol said:
By virtue of the fact that semantic understanding is rule-based
Tournesol said:
By standard semantics, possession of undertanding is *necessary* to report.
The question is not whether “the ability to report requires understanding” but whether “understanding requires the ability to report”
If you place me in situation where I can no longer report what I am thinking (ie remove my ability to speak and write etc), does it follow that I suddenly cease to understand? Of course not.
Tournesol said:
Can Tournesol provide an example of any sentence in the English language which includes the term “red” which Mary necessarily cannot “semantically understand” by virtue of her lack of experiential knowledge of red?
Tournesol said:
1) "What red looks like"
2) "The experiential qualities of red which cannot be written down"
Mary can semantically understand the statement “what red looks like” without knowing what red looks like. The statement means literally “the sense-experience created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm”. This is the semantic meaning of the statement “what red looks like”.
Mary can semantically understand the statement “the experiential qualities of red which cannot be written down” without knowing the experiential qualities of red. The statement means literally “the sense-experiences created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm”. This is the semantic meaning of the statement “the experiential qualities of red which cannot be written down”.
Thus I have shown that Mary can indeed semantically understand both your examples.
Now, can you provide an example of a statement containing the word “red” which Mary CANNOT semantically understand?
What red looks like is nothing to do with semantic understanding of the term red – it is simply “what red looks like”. What red looks like to Tournesol may be very different to what red looks like to MF, but nevertheless we both have the same semantic understanding of what is meant by red, because that semantic understanding is independent of what red looks like.
The experiential qualities of red are nothing to do with semantic understanding of the term red – these are simply “the experiential qualities of red”. The experiential qualities of red for Tournesol may be very different to The experiential qualities of red for MF, but nevertheless we both have the same semantic understanding of what is meant by red, because that semantic understanding is independent of the experiential qualities of red.
The confusion between “experiential qualities” and “semantic understanding” arises because there there are two possible, and very different, meanings to (interpretations of) the simple question “what is the colour red?”
One meaning (based on subjective experiential knowledge of red) would be expressed “what does the colour red look like?”.
The other meaning (the objective semantic meaning of red) would be expressed as “what is the semantic meaning of the term red?”.
This is a perfect illustration of the fact that we need to be very careful when using everyday words in scientific debate, to make sure that we are not confusing meanings.
Tournesol said:
To say that semantics is not derived from the syntactical SMART does not mean
it is derived from some other SMART. You have yet to issue a positive argument
that SMART is sufficient for semantics.
You are the one asserting that semantics is necessarily NOT rule-based. I could equally say the onus is on you to show why it is not.
Tournesol said:
You have also yet to explain what
you consider the "correct" AI argument to be.
Answered above
moving finger said:
No, I’m saying that any two agents may differ in their semantic understanding, inlcuding human agents. Two human agents may “semantically understand” a particular concept differently, but it does not follow that one of them “understands” and the other “does not understand”.
Tournesol said:
What relevance does that have to the CR? If the TT cannot establish that a
system understands correctly, how can it establish that it understands at all
?
Very relevant. If the CR passes most of the Turing test, but fails to understand one or two words because those words are simply defined differently between the CR and the human interrogator, that in itself is not sufficient to conclude “the CR does not understand”
Tournesol said:
The argument that syntax undeterdetermines sematics relies on the fact that
syntactical rules specify transformations of symbols relative to each other --
the semantics is not "grounded". Appealing to another set of rules --
another SMART -- would face the same problem.
“Grounded” in what in your opinion? Experiential knowledge?
What experiential knowledge do I necessarily need to have in order to have semantic understanding of the term “house”?
Tournesol said:
I most people agree on the definitons of the words in a sentence, what
would stop that sentence being an analytic truth, if it is analytic ?
If X and Y agree on the definitions of words in a statement then they may also agree it is analytic. What relevance does this have?
Tournesol said:
There is a balance to be struck. You seem to wish to draw the balance such that “understanding requires consciousness by definition, and that’s all there is to it”, whereas I prefer to define understanding in terms of its observable and measurable qualities,
Tournesol said:
How do you know they are its qualities, in the complete absence of a
defition ? Do they have name-tags sewn into their shorts ?
You are not reading my replies, are you? I never said there should be no definitions, I said there is a balance to be struck. Once again you seem to be making things up to suit your argument.
Tournesol said:
Why should it matter that "the “experiential knowledge of red” is purely subjective".
Are you supposing that subjective knowledge doesn't matter for semantics ?
I am suggesting that subjective experiential knowledge is not necessary for semantic understanding. How many times do you want me to repeat that?
Tournesol said:
They should be broadly similar if our brains are broadly similar.
“Broadly similar” is not “identical”.
A horse is broadly similar to a donkey, but they are not the same animal.
Tournesol said:
you are not aware that some of the things you are saying have implications
contrary to what you are trying to assert explicitly.
You are perhaps trying to read things into my arguments that are not there, to support your own unsupported argument. When I say “there is no a priori reason why they should be identical” this means exactly what it says. With respect if we are to continue a meaningful discussion I suggest you start reading what I am writing, instead of making up what you would prefer me to write.
Tournesol said:
You need experience to grasp the semantics of "red" and "green" as well as other people, because
they base their semantic grasp of these terms on their experiences.
I certainly do not. Red is the sense-experience created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm. This is a semantic understanding of red. What more do I need to know? Whether or not I have known the experiential quality of seeing red makes absolutely no difference to this semantic understanding.
moving finger said:
What I see as green, you may see as red, and another person may see as grey – yet that would not change the “semantic understanding that each of us has of these colours” one iota.
Tournesol said:
that is a classically anti-physicalist argument.
It may be a true argument, but it is not necessarily anti-physicalist.
Tournesol said:
Secondly, it doesn't mean that we are succeeding in grasping the experiential
semantics in spite of spectrum inversion; it could perfectly well be a
situation in which the syntax is present and the semantics are absent.
The semantics is completely embodied in the meaning of the term red – which is the sense-experience created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm.
moving finger said:
What then, do I NOT understand about X-rays, which I WOULD neceessarily understand if I could “see” X-rays?
Tournesol said:
What they look like, experientially.
What they look like is an experiential quality, it is not semantic understanding.
Perhaps you would claim that I also do not have a full understanding of red because I have not tasted red? And what about smelling red?
Tournesol said:
Clearly experiential semantics conveys understanding of
experience.
I can semantically understand what is meant by the term “experience” without actually “having” that experience.
Tournesol said:
We might be able to transfer information directly
form one computer to another, or even from one brain to another
anatomically similar one. But how do you propose to get it into the CR?
The CR already contains information in the form of the rulebook
Tournesol said:
You haven't supplied any other way the CR can acquire semantics.
Sematics is rule-based, why should the CR not possesses the rules for semantic understanding?
Tournesol said:
I'll concede that if you solve the Hard Problem, you might be able to
programme in semantics from scratch. There are a lot of things
you could do if you could solve the HP.
Please define the Hard Problem.
Tournesol said:
Because human languages contain vocabulary relating to human senses.
And I can have complete semantic understanding of the term red, without ever seeing red.
Tournesol said:
If its ability to understand cannot be established on the basis of having
the same features asd human understanding -- how else can it be established.
By defintion ?
By reasoning and experimental test.
Tournesol said:
Achieved solely by SMART has the same problems as achieved solely by syntax.
You have not shown that semantic understanding requires anything other than a knowledge and an understanding of the relevant semantic rules
Tournesol said:
Do I have a way of knowing whether phsycialism is true ?
You don’t. And I understand that many people do not believe it is true.
Tournesol said:
We have been through all this: you can be too
anthropocentric, but you can be insufficiently anthropocentric too.
And my position is that I believe arbitrary definitions such as “understanding requires consciousness” and “understanding requires experiential knowledge” are too anthropocentrically biased and cannot be defended rationally
Tournesol said:
Well, that's the anti-physicalist's argument.
It’s my argument. I’m not into labelling people or putting them into boxes.
I see no reason why X’s subjective experience of seeing red should be the same as Y’s
Tournesol said:
The question was the term "qualia". You could infer "house" on analogy with
"palace" or "hut". You could infer "X Ray" on analogy with "light". How
can you infer "qualia" without any abalogies ?
By “how do I semantically understand the term qualia”, do you mean “how do I semantically understand the term experiential quality”?
Let me give an example – “the experiential quality of seeing red” – which is “the sense-experiences created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm”. What is missing from this semantic understanding the experiential quality of seeing red?
Tournesol said:
you
claim to be a physicalist.
To my knowledge I have made no such claim in this thread
Tournesol said:
Anyway, experience has to do with the semantics of expreiential language.
Semantic understanding has nothing necessarily to do with experiential qualities, as I have shown several times above
Tournesol said:
It is not part of your definition of understanding -- how remarkably
convenient.
And remarkably convenient that it is part of yours?
The difference is that I can actually defend my position that experiential knowledge is not part of understanding with rational argument and example – the Mary experiment for example.
Tournesol said:
Ask a blind person what red looks like.
He/she has no idea what red looks like, but it does not follow from this that he does not have semantic understanding of the term red, which is “the sense-experiences created within an agent which is endowed with visual-sensing apparatus when it perceives electromagnetic radiation with wavelengths of the order of 650nm”. Experiential knowledge is not part of this semantic understanding.
Tournesol said:
Is that any easier than solving the Hard problem, or is it part of the Hard
problem?
Please define what you understand to be the Hard Problem
Tournesol said:
Yes there is: all brains are broadly similar anatomically
As before, “broadly similar” is not synonymous with “identical”.
Tournesol said:
. If they were not,
you could not form a single brain out the two sets of genes you get from your
parents. (Argument due to Steven Pinker).
Genetically identical twins may behave similarly, but not necessarily identically. Genetic makeup is only one factor in neurophysiology.
Tournesol said:
You might be able to give the CR full semantics by solving the HP; but that
leads to a version of AI that Searle does not disagree with.
Please define what you mean by the Hard Problem
Tournesol said:
this is a style of
argument you dislike when others use it.
It is not a question of “disliking”.
If a position can be supported and defended with rational argument (and NOT by resorting solely to “definition” and “popular support”) then it is worthy of discussion. I have put forward the “What Mary does not understand about red” thought experiment in defence of my position that
experiential knowledge is not necessary for semantic understanding, and so far I am waiting for someone to come up with a statement including the term red which Mary cannot semantically understand. The two statements you have offered so far I have shown can be semantically understood by Mary.
Tournesol said:
You might be able to give the CR full semantics by closing the explanatory
gap in some unspecified way; but that is speculation.
What “explanatory gap” is this?
MF