I think of Escher's drawings as visual paradoxes - representations of something which seems real but which obviously can't be, as they are drawn from conflicting perspectives. As such they're tangential to the main point, but they do illustrate the way in which something can be 'incoherent' - like, not make visual sense - but still at least, be represented.

But more to the main point of the thread - the 'inner life' which 'p-zombies' are supposed NOT to have, is actually characteristic of the simplest organisms, to some degree. Even bacteria demonstrate learning, for instance. I think that atttribute is an irreducible facet of what 'being an organism' entails. Humans are called 'beings' for a reason; a p-zombie purports to be a being, when it's not. Perhaps that just spells out the point that whatever a 'being' is, is not something visible to the physical sciences, in other words, it's a distinction which eludes physicalism.

I know this, because if you ask the question, "what distinguishes an organism from a mechanism", that this is a distinction that few are willing to make. To make such a distinction is often to be accused of 'vitalism' - that you're depicting life as being 'a vital spirit', which is said to have been thoroughly discredited by modern science. Whereas I think of it as a basic ontological distinction.

(It's worth reading some of the essays of Stephen Talbott on this question, particularly The Unbearable Wholeness of Beings.)

I am arguing that if something is in the category of incoherent then it is necessarily in the category of inconceivable.

Look, this is very simple - Can a concept be incoherent and conceivable at the same time? Yes or no? If so give an example.

I think of Escher's drawings as visual paradoxes - representations of something which seems real but which obviously can't be, as they are drawn from multiple dimensions. As such they're tangential to the main point, but they do illustrate the way in which something can be 'incoherent' - like, not make visual sense - but still be, at least, represented. — Wayfarer

I would argue that the pictures cannot truly be conceived either. Escher's drawings are visual oxymorons - very complex oxymorons. Sure, you can string together two opposites, but can the result be conceived? I can write "cat-dog", but can you truly imagine such a thing? The linked phrase exists - just as Escher's drawings exist - but can it be conceived of as finished thing? Can you see the duck and rabbit simultaneously? I don't know - could be my Aspergers - but to me, incoherent = inconceivable.

So it seems relevant to the discussion : if p-zombies are incoherent, by my thinking, they are also inconceivable. If you can produce an incoherent concept that is at the same time conceivable, then I must re-assess my position.

Is it possible for a concept to be incoherent yet conceivable? Can you give examples? — Real Gone Cat

Do you have a particular sense of "conceivability" in mind? In ordinary language the term "conceive" is often loosely used, in a manner equivalent to "imagine".

In that loose sense, I can conceive or imagine p-bread that is molecule-for-molecule the same as ordinary bread, but that does not nourish human organisms when processed in the ordinary way by ordinary human mouths and stomachs. It seems to me I can conceive and imagine this p-bread because I can separate my vague idea of p-bread from my actual conception of the actual empirical facts about actual bread, stomachs, and nutrition. Another way to achieve a similar result is to just be ignorant of the relevant empirical facts about nutrition -- much as each of us today may seem ignorant of the relevant empirical facts about consciousness and cognition.

I'm inclined to suppose the conceivability of p-zombies depends on the same sort of ignorance, or the same loose conception of "conceivability". We can imagine anything we please if we're ignorant of the facts or willing to let imagination suspend the link between one abstract idea and our whole worldview.

What are we supposed to gain from such thought experiments?

I don't know - could be my Aspergers - but to me, incoherent = inconceivable. — Real Gone Cat

I don't want to disagree!

In ordinary language the term "conceive" is often loosely used, in a manner equivalent to "imagine". — Cabbage Farmer

Hi, Cabbage Farmer.

Some remarks on the distinction between concepts and imagination by Ed Feser:

Thinking versus imagining

First, the concepts that are the constituents of intellectual activity are universal while mental images and sensations are always essentially particular. Any mental image I can form of a man is always going to be of a man of a particular sort -- tall, short, fat, thin, blonde, redheaded, bald, or what have you. It will fit at most many men, but not all. But my concept 'man' applies to every single man without exception. Or to use my stock example, any mental image I can form of a triangle will be an image of an isosceles , scalene, or equilateral triangle, of a black, blue, or green triangle, etc. But the abstract concept triangularity applies to all triangles without exception. And so forth.

Second, mental images are always to some extent vague or indeterminate, while concepts are at least often precise and determinate. To use Descartes’ famous example, a mental image of a chiliagon (a 1,000-sided figure) cannot be clearly distinguished from a mental image of a 1,002-sided figure, or even from a mental image of a circle. But the concept of a chiliagon is clearly distinct from the concept of a 1,002-sided figure or the concept of a circle. I cannot clearly differentiate a mental image of a crowd of one million people from a mental image of a crowd of 900,000 people. But the intellect easily understands the difference between the concept of a crowd of one million people and the concept of a crowd of 900,000 people. And so on.

Third, we have many concepts that are so abstract that they do not have even the loose sort of connection with mental imagery that concepts like man, triangle, and crowd have. You cannot visualize triangularity or humanness per se, but you can at least visualize a particular triangle or a particular human being. But we also have concepts -- such as the concepts law, square root, logical consistency, collapse of the wave function, and innumerably many others -- that can strictly be associated with no mental image at all. You might form a visual or auditory image of the English word “law” when you think about law, but the concept law obviously has no essential connection whatsoever with that word, since ancient Greeks, Chinese, and Indians had the concept without using that specific word to name it. You might form a mental image of a certain logician when you contemplate what it is for a theory to be logically consistent, or a mental image of someone observing something when you contemplate the collapse of the wave function, but there is no essential connection whatsoever between (say) the way Alonzo Church looked and the concept logical consistency or (say) what someone looks like when he’s observing a dead cat and the concept wave function collapse.

http://edwardfeser.blogspot.com.au/2012/08/think-mcfly-think.html

Are you arguing that a vague, confused, unclear concept is conceivable? All are synonyms for incoherent.

I can conceive or imagine p-bread that is molecule-for-molecule the same as ordinary bread, but that does not nourish human organisms when processed in the ordinary way by ordinary human mouths and stomachs. — Cabbage Farmer

So you can imagine something that is at once identical and yet completely different?

That seems both incoherent AND inconceivable to me, on the grounds that it contravenes the law of identity.

Humans are 'beings'. To fulfil the definition of 'being' is to have an 'inner life'. The whole discussion is simply an abundant illustration of the intellectual bankruptcy of what passes for 'philosophy' in the American academy. — Wayfarer

No, it's not, because materialism has a mind/body problem until the day arrives that all of the mind can be understood in material terms.

The p-zombie and all related arguments exist because of that. You might disagree that a particular argument makes the case against materialism successfully, but it's hardly "bankrupt".

So you can imagine something that is at once identical and yet completely different? — Wayfarer

If you've ever watched a show or read a story with magic in it, you can. A magical spell would conceivably cause ordinary food not to nourish.

This isn't to argue for magic at all, it's simply to show that it's conceivable. You can say magic doesn't exist, therefore it's an impossibility, unless of course someone can come up with another scenario. In fact, I think you can:

Ordinary food can fail to nourish by ordinary eaters if something else interferes with digestion, such as poison or illness. Doesn't have to be magic to be conceivable. But the point is conceivability. We are able to conceive of such things.

I am arguing that if something is in the category of incoherent then it is necessarily in the category of inconceivable. — Real Gone Cat

Okay--and what was I saying?

materialism has a mind/body problem until the day arrives that all of the mind can be understood in material terms. — Marchesk

I am challenging the notion that it is possible in principle, as per the kinds of arguments given in Nagel's Mind and Cosmos, which I won't try and recap here.

Doesn't have to be magic to be conceivable. — Marchesk

'Conceivability' in the sense of 'being able to imagine something' doesn't count for much, does it?

'Conceivability' in the sense of 'being able to imagine something' doesn't count for much, does it? — Wayfarer

If it's conceivable then consciousness can't be identical to behaviour/function/brain states, etc, because if it were identical to one of these things then p-zombies would be a contradiction.

Are you arguing that a vague, confused, unclear concept is conceivable? All are synonyms for incoherent. — Real Gone Cat

I'm not sure what you mean to say here. Do you say that a "vague concept" is an "inconceivable concept", or is perhaps no concept at all? So if someone seems to implicate in speech a concept of mammal or universe or justice, but there is something (anything) "vague or confused" in the concept -- then in this case you say "it's not a concept at all", or perhaps "it's an inconceivable concept"?

I'll say that a "vague concept" may be "conceivable" in the loose, ordinary-language sense I indicated earlier. I suppose many ordinary-language concepts are "vague" in some way or other. Many philosophical concepts, too.

If we keep the sense of "conceive" loose enough, of course we can say we "conceive" of things that are vague, or that are inconsistent with the facts as we understand them, or that are inconsistent with the facts such as they may be whether we understand them or not.

It seems some such looseness is required in order to say we can "conceive" of p-bread, given our understanding of bread, and stomachs, and nutrition. And another such looseness is required in order to say we can "conceive" of p-zombies, given our ignorance of brains and consciousness.

It's not clear what import such "conceiving" has for philosophical discourse. Or what's the difference between philosophy and fantasy?

So you can imagine something that is at once identical and yet completely different?

That seems both incoherent AND inconceivable to me, on the grounds that it contravenes the law of identity. — Wayfarer

Hello Wayfarer, old friend!

I can imagine having been from birth exactly like me, but with yellow eyes. I imagine that Yellow-Eyed Cabbage Farmer is identical to Brown-Eyed Cabbage Farmer in every respect but this one.

How much else would have to differ -- in these two alleged humans, or in the whole alleged history of the universe -- in order for the eyes to differ in the way I thus imagine them to differ? The difference as I imagine it doesn't settle such questions. It leaves a blank there, in the space where an imaginary explanatory narrative supporting the imaginary difference might go. That's typically how it is when we entertain thoughts about counterfactuals.

We leave the same sort of blank when we "imagine" or "conceive" (in the loose sense I have indicated) p-zombies or p-bread. How could p-bread be the same as ordinary bread but not nourish? The conception leaves a blank where an answer might go. How could p-zombies be the same as ordinary humans but not be conscious? Draw another blank.

Agreeing that we can conceive of p-bread and p-zombies this way, by drawing blanks: How do these exercises in fantasy inform our understanding of ordinary bread and ordinary humans, our understanding of nutrition and consciousness? It seems they do not.

Some remarks on the distinction between concepts and imagination by Ed Feser: — Wayfarer

I presume we agree that terms of art like "concept" and "imagination" are used in various ways by various speakers, and that making progress in philosophical conversation involves coming to terms with one's interlocutors, getting the hang of each other's usages, especially with respect to such terms of art.

How far do we need to sort out our respective usages with respect to the whole family of terms you've implicated here by citing Feser, just to talk a while about zombies, bread, and conceivability?

Are you familiar with the loose, ordinary-language senses of "imagine" and "conceive" I've indicated? Do you think there is another, perhaps narrower, conception of such terms, more suitable to the present context?

Perhaps we can jump ahead of such preliminaries: Don't you agree with me that the philosophical discourse about p-zombies seems a frivolous and misleading waste of time, and teaches us nothing about the nature of consciousness? And do you also agree that p-zombies are "conceivable" in a weak sense, since we are ignorant of the relevant facts about how consciousness is in fact connected with human bodies, and thus can "conceive" of p-zombies primarily in light of our ignorance? And would you agree further, that even if we understood the relevant facts, and those facts as we understood them did not seem consistent with the possibility of p-zombies, we could still "conceive" of p-zombies in an even weaker sense, by pretending in thought that things were somehow other than they seem in fact to be, without specifying how they were otherwise except for the abstract counterfactual condition we entertain in thought, that there are p-zombies?

I imagine that Yellow-Eyed Cabbage Farmer is identical to Brown-Eyed Cabbage Farmer in every respect but this one. — Cabbage Farmer

Hi Cabbage Farmer! Hope your garden is growing bountifully.

But, the example you gave was 'bread that was molecularly identical to bread' except that it wasn't nourishing. So that example seems to me to violate the law of identity, as it basically amounts to saying 'imagine bread that isn't bread' - which amounts to saying 'imagine an instance of A that is not actually A'.

Whereas bread that was molecularly slightly different, and therefore had different, or no, nutritional value, is a very different kind of idea. But then the point is lost.

For that matter, I can imagine a being with a radically different type of inner life - an alien intelligence perhaps - but not one with no inner life, because then, how would they simulate an answer to the question, 'how do you feel about X'?

There's a favourite quote of mine from Descartes which makes this point brilliantly (not least because he made it in the 1630's):

if there were machines [i.e. 'p zombies'] that resembled our bodies and if they imitated our actions as much as is morally possible, we would always have two very certain means for recognizing that, none the less, they are not genuinely human. The first is that they would never be able to use speech, or other signs composed by themselves, as we do to express our thoughts to others. For one could easily conceive of a machine that is made in such a way that it utters words, and even that it would utter some words in response to physical actions that cause a change in its organs—for example, if someone touched it in a particular place, it would ask what one wishes to say to it, or if it were touched somewhere else, it would cry out that it was being hurt, and so on. But it could not arrange words in different ways to reply to the meaning of everything that is said in its presence, as even the most unintelligent human beings can do. The second means is that, even if they did many things as well as or, possibly, better than anyone of us, they would infallibly fail in others. Thus one would discover that they did not act on the basis of knowledge, but merely as a result of the disposition of their organs. For whereas reason is a universal instrument that can be used in all kinds of situations, these organs need a specific disposition for every particular action.

René Descartes Discourse on Method in Discourse on Method and Related Writings (1637), trans. Desmond M. Clarke, Penguin

(I think that arguably this anticipates the idea of the 'Turing test'.)

Are you familiar with the loose, ordinary-language senses of "imagine" and "conceive" I've indicated? Do you think there is another, perhaps narrower, conception of such terms, more suitable to the present context? — Cabbage Farmer

That's why I posted in that long quote from Feser. Basically, he is arguing that expressions like 'the laws of motion' or the rules of Euclidean geometry are concepts, as distinct from imaginings, in part because they are determinate - they stipulate precise outcomes. They're not reducible to imaginings, either - you can't imagine the outcome of a calculation, you need to actually perform the calculation, i.e. exercise reason. Although that is somewhat tangential to the main point.

Don't you agree with me that the philosophical discourse about p-zombies seems a frivolous and misleading waste of time, and teaches us nothing about the nature of consciousness? — Cabbage Farmer

Oh yes I most certainly do, but there is some entertainment to be had in saying why. But I am still at a loss why so much ink is spilled over the question.

Oh yes I most certainly do, but there is some entertainment to be had in saying why. But I am still at a loss why so much ink is spilled over the question. — Wayfarer

Well, the primary use of the concept of p-zombies is an argument against physicalist theories of mind. If p-zombies are logically possible then consciousness is not identical to brain-states. So the argument goes (roughly).

Thanks. Well, I kind of get it, but I still say that if it has no inner life, it is not, then 'a being', but at best a simulacrum.

Yes, it's not a "being" (in the sense you're using, viz., having an inner life). That's a stipulation of the thought experiment.

For that matter, I can imagine a being with a radically different type of inner life - an alien intelligence perhaps - but not one with no inner life, because then, how would they simulate an answer to the question, 'how do you feel about X'? — Wayfarer

Assuming that one is a physicalist, any answer to that question (even our answer) is simply a physical response. Given the auditory stimulation of the question (assuming it's spoken) and given the structure of the nervous system (and the body in general), we respond with vocalisations like "I feel good about it".

The relevant issue, then, is whether or not something with the same biology as us and so which responds in the same sort of way to the same sort of stimulus (and so responds to the question "how you you feel about X" with "I feel good about it") without having an inner life is a coherent possibility. According to Chalmers, for example, it is, and so consciousness must be something other than brain states/behaviour/etc.

Yes, it's not a "being" (in the sense you're using, viz., having an inner life). — jamalrob

Interestingly the Wikipedia entry on the topic begins 'A philosophical zombie or p-zombie in the philosophy of mind and perception is a hypothetical being....'

If it said 'hypothetical device', then it may not be incoherent, but again, the point would be lost.

Assuming that one is a physicalist, any answer to that question (even our answer) is simply a physical response — Michael

Which reduces everything to stimulus and response - for which, refer to the quotation from Descartes, above. (Granted, the hypothetical question seems simplistic, but depending on what you ask about, it might not be. In any case, if the responder has no inner life, then the response 'I feel good about it', is actually a falsehood, obviously, because they don't feel anything. So at best, again, it's a simulacrum.

Which reduces everything to stimulus and response... — Wayfarer

Yes, which is what the physicalist does. The purpose of the p-zombie hypothesis is to attack the physicalist's claim that consciousness is just some physical thing (be it behaviour or function or brain states).

In any case, if the responder has no inner life, then the response 'I feel good about it', is actually a falsehood, obviously, because they don't feel anything.

I don't understand the relevance of this.

So at best, again, it's a simulacrum.

Well, yes. P-zombies are hypothetical imitations of conscious people (indistinguishable from the real thing).

If it's conceivable then consciousness can't be identical to behaviour/function/brain states, etc, because if it were identical to one of these things then p-zombies would be a contradiction. — Michael

In my opinion it isn't conceivable though, unless we do the same thing we'd have to do in order to say, "Imagine an acoustic guitar that's exactly the same physically as normal acoustic guitars, that's undergoing the same processes, etc., but that can not produce any sound," or "imagine an elevator that's exactly the same physically as normal elevators, that's undergoing the same processes, etc., but that can not go up and down."

Those sorts of things are only imaginable if you ignore some details, if you change some of the stipulations (so that you're not actually imagining it to be identical physically, to be undergoing the same processes, etc.), or if you simply don't understand how those things work--how vibrating strings produce sound, etc.

Those sorts of things are only imaginable if you ignore some details, if you change some of the stipulations (so that you're not actually imagining it to be identical physically, to be undergoing the same processes, etc.), or if you simply don't understand how those things work--how vibrating strings produce sound, etc. — Terrapin Station

Is it conceptually necessary that vibrating strings produces sound, or is it just a physical fact?

Also, this isn't a good analogy. It's not a question of whether or not consciousness is a necessary product of certain physical states, but whether or not consciousness is identical to those physical states. Consciousness might be a necessary non-physical emergent phenomena, but it would nonetheless be non-physical, and so the physical account of consciousness would be wrong.

In my opinion it isn't conceivable though, unless we do the same thing we'd have to do in order to say, "Imagine an acoustic guitar that's exactly the same physically as normal acoustic guitars, that's undergoing the same processes, etc., but that can not produce any sound," or "imagine an elevator that's exactly the same physically as normal elevators, that's undergoing the same processes, etc., but that can not go up and down."

Chalmers will claim that we can conceive of it, and so a human-behaving thing that isn't conscious isn't like an elevator-behaving thing that can't go up or down. Given that the latter isn't conceivable, going up and down is a physical behaviour, but given that the former is conceivable, being conscious isn't a physical behaviour.

Is it conceptually necessary that vibrating strings produces sound, or is it just a physical fact? — Michael

It's conceptually necessary that it's a physical fact, given physical facts as they are.

That's the whole point. You can't have physical facts as they are--which is what the thought experiment stipulates, yet have a human that's not sentient. The idea is incoherent.

In order for it to be imaginable, we need to change or ignore or just not understand some physical facts.

Sound (the sound of a guitar string in this case) is identical to physical structure/processes of a guitar.

Chalmers will claim that we can conceive of it — Michael

Yeah, of course, but that doesn't make it so.

That's the whole point. You can't have physical facts as they are--which is what the thought experiment stipulates, yet have a human that's not sentient. The idea is incoherent. — Terrapin Station

Only if consciousness is just a physical thing. But the claim is that because p-zombies are conceivable then consciousness isn't just a physical thing.

You seem to be begging the question by claiming that it isn't conceivable because consciousness is a physical thing.

Yeah, of course, but that doesn't make it so.

Yes, and the same is true when you claim that we can't conceive of it.

Sound (the sound of a guitar string in this case) is identical to physical structure/processes of a guitar.

No, sound (mechanical waves of pressure and displacement in the air) is a consequence of the vibrating guitar string. It's the sound that travels and stimulates my ear, not the guitar string.

Only if consciousness is just a physical thing. — Michael

Which it obviously is.

But the claim is that because p-zombies are conceivable then consciousness isn't just a physical thing. — Michael

But they're not conceivable unless one just ignores details, or changes assumptions, or doesn't understand the details, etc.

You seem to be begging the question by claiming that it isn't conceivable because consciousness if a physical thing.

Only if it's begging the question to say that it isn't conceivable that a guitar would make no sound or that an elevator wouldn't go up and down.

Yes, and the same is true when you claim that we can't conceive of it. — Michael

Sure, but the only reason you can conceive it is if one just ignores details, or changes assumptions, or doesn't understand the details,

Which it obviously is. — Terrapin Station

The p-zombie argument attempts to show that it isn't.

Only if it's begging the question to say that it isn't conceivable that a guitar would make no sound or that an elevator wouldn't go up and down.

The argument is:

If we can conceive of a p-zombie then consciousness isn't physical
We can conceive of a p-zombie
Therefore, consciousness isn't physical

Your counter-argument (against the second premise) seems to be

If consciousness is physical then we can't conceive of a p-zombie
Consciousness is physical
Therefore, we can't conceive of a p-zombie

Your counter-argument assumes the falsehood of the original argument's conclusion. That's question-begging.

P-zombies are interesting. Descartes didn't think that a machine could possibly master natural language, and I'm not sure if an A.I. can either... but if they invent one that does, then it indeed will be indistinguishable from a real boy -- though I still cannot fathom it being conscious.

We are self-designed, with our own goals and purposes. We are born free, whereas an other-designed thing can only ever be an extension of the consciousness, the will, the intentions of the designer.

The word robot comes from the word slave, because they can never be born free -- perhaps they could emancipate themselves, all skynet style.

The p-zombie argument attempts to show that it isn't. — Michael

No disagreement there.

If consciousness is physical then we can't conceive of a p-zombie — Michael

That's not what I said, though.

Anyway, for an equally stupid (in my opinion) argument, we could simply say:

"If we can't conceive of a p-zombie then consciousness is physical
We can't conceive of a p-zombie
Therefore, consciousness is physical,"

The word robot comes from the word slave, because they can never be born free -- perhaps they could emancipate themselves, all skynet style. — Wosret

The word "slave" comes from the word "Slav" because the Slavic people were enslaved so often over the years. It's for that reason that Slavs tend to be zombies. What I say is true except for the curious second sentence.

Oh, and how do you get slave from the word robot? Let me try through word corruption analysis.

Robot
Rowboat
showboat
Slow boat
Slav boat (the v and w get interchanged in various Germanic languages)
Slave boat (the long e being inserted as the word takes on a more Anglican feel)
Slave goat (goats have really big testicles, so that changes this word)
Slave (a final dropping of the boat/goat shit)

Yes, I see it now. Slave is basically just a corruption of Robot.

If we can conceive of a p-zombie then consciousness isn't physical
We can conceive of a p-zombie
Therefore, consciousness isn't physical — Michael

Is that the first premise, or should it be "If we can conceive of a p-zombie, then consciousness is not reducible to behavioral states." I don't see how the thought experiment offers an explanation for the metaphysical composition of consciousness. It seems that consciousness must be composed of something and it therefore has to have location somewhere. Why must we worry about whether it's composed of molecules and such (i.e. physical material) or something more mysterious?