There must be non-physical things to assume that there is any difference between “us” and “p-zombies”. This is a logical requirement. They posit that there effectively is a difference, in the premises right there, by asserting that p-zombies do not have qualia, while we do.
Premise: P-zombies have all the physical and logical stuff that we do.
Premise: P-zombies DO NOT have qualia.
Premise: We have qualia.
Implied premise: This thought experiment is logically consistent.
The only way 4 is possible is if it is also implied that:
Implied premise: Either us, or P-Zombies, have something magical that adds or removes qualia.
By the reasoning which prompts them to come up with the thought experiment in the first place, it cannot be the zombies that have an additional magical component, because this would contradict the implied premise that the thought experiment is logically consistent (and would question the usefulness and purpose of the thought experiment).
Therefore:
“Conclusion”: We have something magical that gives us qualia.
The p-zombie thought experiment is usually intended to prove that qualia is magical, yes. This is one of those unfortunate cases of philosophers reasoning from conceivability, apparently not realising that such reasoning usually only reveals stuff about their own mind.
I wouldn’t say “qualia is magic” is actually a premise, but the argument involves assuming “qualia could be magical” and then invalidly dropping a level of “could”.
In this case the “could” is an epistemic “could”—“I don’t know whether qualia is magical”. Presumably, iff qualia is magical, then p-zombies are possible (ie. exist in some possible world, modal-could), so we deduce that “it epistemic-could be the case that p-zombies modal-could exist”. Then I guess because epistemic-could and modal-could feel like the same thing¹, this gets squished down to “p-zombies modal-could exist” which implies qualia is magical.
Anyway, the above seems like a plausible explanation of the reasoning, although I haven’t actually talked to ay philosophers to ask them if this is how it went.
¹ And could actually be (partially or completely) the same thing, since unless modal realism is correct, “possible worlds” don’t actually exist anywhere. Or something. Regardless, this wouldn’t make the step taken above legal, anyway. (Note that the previous “could” there is an epistemic “could”! :p)
I had always understood that “We have something magical that gives us qualia” was one of the explicit premises of p-zombies (p-zombies being defined as that which lacks that magical quality, but appears otherwise human). One could then see p-zombies as a way to try to disprove the “something magical” hypothesis by contradiction—start with someone who doesn’t have that magical something, continue on from there, and stop once you hit a contradiction.
We have something magical that gives us qualia” was one of the explicit premises of p-zombies
Nope. eg.
According to physicalism, all that exists in our world (including consciousness) is physical.
Thus, if physicalism is true, a logically-possible world in which all physical facts are the same as those of the actual world must contain everything that exists in our actual world. In particular, conscious experience must exist in such a possible world.
In fact we can conceive of a world physically indistinguishable from our world but in which there is no consciousness (a zombie world). From this (so Chalmers argues) it follows that such a world is logically possible.
Therefore, physicalism is false. (The conclusion follows from 2. and 3. by modus tollens.)
(Chalmer’s argument according to WP)
One could then see p-zombies as a way to try to disprove the “something magical” hypothesis by contradiction
Thus, if physicalism is true, a logically-possible world in which all physical facts are the same as those of the actual world must contain everything that exists in our actual world. In particular, conscious experience must exist in such a possible world.
In fact we can conceive of a world physically indistinguishable from our world but in which there is no consciousness (a zombie world). From this (so Chalmers argues) it follows that such a world is logically possible.
These two steps are contradictory. In the first one, you state that a world physically indistinguishable from ours must include consciousness; then in the very next point, you consider a world physically indistinguishable from ours which does not include consciousness to be logically possible—exactly what the previous step claims is not logically possible.
So the second is then implicitly assuming that physicalism is not true; it seems to me that the whole argument is basically a longwinded way of saying “I can’t imagine how consciousness can possibly be physical, therefore since I am conscious, physicalism is false”.
One might as easily imagine a world physically indistinguishable from ours, but in which there is no gravity, and thence conclude that gravity is not physical but somehow magical.
For some values of “imagine”. Given relativity, it would be pretty difficult to coheretly unplug gravity from mass, space and acceleration. It would be easier under Newton. I conclude that the unpluggabiliy of qualia means we just don’t have a relativity-grade eplanation of them, an explanation that makes them deeply interwoven with other things.
I conclude that the unpluggabiliy of qualia means we just don’t have a relativity-grade eplanation of them, an explanation that makes them deeply interwoven with other things.
Inertia and mass are the same thing. You probably meant “the same proportionality constant between mass and gravitational force”, that is, imagine that the value of Newton’s constant G was different.
But this (like CCC’s grandparent post introducing the gravity analogy) actually goes in Chalmers’ favor. Insofar as we can coherently imagine a different value of G with all non-gravitational facts kept fixed, the actual value of G is a new “brute fact” about the universe that we cannot reduce to non-gravitational facts. The same goes for consciousness with respect to all physical facts, according to Chalmers. He explicitly compares consciousness to fundamental physical quantities like mass and electric charge.
The problem is that one aspect of the universe being conceptually irreducible at the moment (which is all that such thought experiments prove) does not imply it might forever remain so when fundamental theory changes, as Peterdjones says. Newton could imagine inertia without gravity at all, but after Einstein we can’t. Now we are able to imagine a different value of G, but maybe later we won’t (and I can actually sketch a plausible story of how this might come to happen if anyone is interested).
No, I meant a form of matter which coexisted with current forms of matter but which was accelerated by a force disproportionately to the amount of force exerted through the gravity force. One such possibility would be something that is ‘massless’ in that it isn’t accelerated by gravity but that has electric charge.
And by definition, the value of G is equal to 1, just like every other proportionality constant. I wasn’t postulating that MG/NS^2 have a different value.
One might as easily imagine a world physically indistinguishable from ours, but in which there is no gravity, and thence conclude that gravity is not physical but somehow magical.
Oooh, good one. I’m trying this if someone ever seriously tries to argue p-zombies with me.
Within this discussion, I’ve tried to consistently use “magic” as meaning “not physics or logic”. Essentially, things that, given a perfect model of the (physical) universe that we live in, would be considered impossible or would go against all predictions for no cause that we can attribute to physics or logic or both.
So dualism is only one example, another could be intervention by the Lords of the Matrix (depending on how you draw boundaries for “universe that we live in”), and God or ontologically basic mental entities could be others.
So the assertion “we have something magical” is equivalent to “qualia is made of nonlogics” (although “nonlogics” is arguably still much more useful than “nonapples” as a conceptspace pointer).
Errr, yes..that is the intended conclusion. But I don’t think you can say an argument is question begging beccause the intended conclusion follows from the premises taken jointly.
And how, pray tell, did they reach into the vast immense space of possible hypotheses and premises, and pluck out this one specific set of premises which just so happens that if you accept it completely, it inevitably must result in the conclusion that we have something magical granting us qualia?
The begging was done while choosing the premises, not in one of the premises individually.
Premise: All Bob Chairs must have seventy three thousand legs exactly. Premise: Things we call chairs are illusions unless they are Bob Chairs. Premise: None of the things we call chairs have exactly seventy three thousand legs. Therefore, all of the things we call chairs are illusions and do not exist.
I seriously don’t see how the above argument is any more reasonable and any more or less question-begging than the p-zombie argument I’ve made in the grandparent. No single premise here assumes the conclusion, right? So no problem!
ETA: Perhaps it’s more clear if I just say that in order for the premises of the grandparent to be logically valid, one must also assume as a premise that having the information patterns of the human brain without creating qualia is possible in the first place. This is the key point that is the source of the question begging: It is assumed that the brain interactions do not create qualia, implicitly as part of the premises, otherwise the statement “P-zombies have the same brain interactions that we do but no qualia” is directly equivalent to “A → B, A, ¬B”.
So for A (brain interactions identical to us), B (possess qualia), and C (has magic):
(A → B) <==> ¬B → ¬A
((C → B) OR (AC → B)) <==> ¬(A → B)
A
¬B
Refactor to one single “question-begging” premise: ((((C ->B) OR (AC → B)) → C) <==> ¬(¬B → ¬A)) AND A AND ¬B
And how, pray tell, did they reach into the vast immense space of possible hypotheses and premises, and pluck out this one specific set of premises which just so happens that if you accept it completely, it inevitably must result in the conclusion that we have something magical granting us qualia?
I suppose they have the ability to formulate arguments that support their views. Are you saying that the honest way to argue is to fling premises together at random and see what happens?
The begging was done while choosing the premises, not in one of the premises individually.
Joint implication by premsies is validity not petitio principi.
Premise: All Bob Chairs must have seventy three thousand legs exactly.
Premise: Things we call chairs are illusions unless they are Bob Chairs.
Premise: None of the things we call chairs have exactly seventy three thousand legs.
Therefore, all of the things we call chairs are illusions and do not exist.
That is an example of a True Scotsman fallacy, or argument by tendentious redefinition. I don’t see the parallel.
However, all they’ve done is pick specific premises that hide clever assumptions that logically must end up with their desired conclusion, without any reason in particular to believe that their premises make any sense. See the amateur logic I did in my edits of the grandparent.
It is very much assumed, by asserting the first, third and fourth premises, that qualia does not require brain interactions, as a prerequisite for positing the existence of p-zombies in the thought experiment.
I have, but unfortunately that’s mostly because I don’t know the formal nomenclature and little details of writing conceivability and possibility logical statements.
I wouldn’t really trust myself to write formal logic with conceivability and probability without missing a step or strawmanning one of the premises at some point, with my currently very minimal understanding of that stuff.
There must be non-physical things to assume that there is any difference between “us” and “p-zombies”. This is a logical requirement. They posit that there effectively is a difference, in the premises right there, by asserting that p-zombies do not have qualia, while we do.
Premise: P-zombies have all the physical and logical stuff that we do.
Premise: P-zombies DO NOT have qualia.
Premise: We have qualia.
Implied premise: This thought experiment is logically consistent.
The only way 4 is possible is if it is also implied that:
Implied premise: Either us, or P-Zombies, have something magical that adds or removes qualia.
By the reasoning which prompts them to come up with the thought experiment in the first place, it cannot be the zombies that have an additional magical component, because this would contradict the implied premise that the thought experiment is logically consistent (and would question the usefulness and purpose of the thought experiment).
Therefore:
“Conclusion”: We have something magical that gives us qualia.
The p-zombie thought experiment is usually intended to prove that qualia is magical, yes. This is one of those unfortunate cases of philosophers reasoning from conceivability, apparently not realising that such reasoning usually only reveals stuff about their own mind.
I wouldn’t say “qualia is magic” is actually a premise, but the argument involves assuming “qualia could be magical” and then invalidly dropping a level of “could”.
In this case the “could” is an epistemic “could”—“I don’t know whether qualia is magical”. Presumably, iff qualia is magical, then p-zombies are possible (ie. exist in some possible world, modal-could), so we deduce that “it epistemic-could be the case that p-zombies modal-could exist”. Then I guess because epistemic-could and modal-could feel like the same thing¹, this gets squished down to “p-zombies modal-could exist” which implies qualia is magical.
Anyway, the above seems like a plausible explanation of the reasoning, although I haven’t actually talked to ay philosophers to ask them if this is how it went.
¹ And could actually be (partially or completely) the same thing, since unless modal realism is correct, “possible worlds” don’t actually exist anywhere. Or something. Regardless, this wouldn’t make the step taken above legal, anyway. (Note that the previous “could” there is an epistemic “could”! :p)
I had always understood that “We have something magical that gives us qualia” was one of the explicit premises of p-zombies (p-zombies being defined as that which lacks that magical quality, but appears otherwise human). One could then see p-zombies as a way to try to disprove the “something magical” hypothesis by contradiction—start with someone who doesn’t have that magical something, continue on from there, and stop once you hit a contradiction.
Nope. eg.
According to physicalism, all that exists in our world (including consciousness) is physical.
Thus, if physicalism is true, a logically-possible world in which all physical facts are the same as those of the actual world must contain everything that exists in our actual world. In particular, conscious experience must exist in such a possible world.
In fact we can conceive of a world physically indistinguishable from our world but in which there is no consciousness (a zombie world). From this (so Chalmers argues) it follows that such a world is logically possible.
Therefore, physicalism is false. (The conclusion follows from 2. and 3. by modus tollens.)
(Chalmer’s argument according to WP)
These two steps are contradictory. In the first one, you state that a world physically indistinguishable from ours must include consciousness; then in the very next point, you consider a world physically indistinguishable from ours which does not include consciousness to be logically possible—exactly what the previous step claims is not logically possible.
Or am I misunderstanding something?
The first includes “if physicalism is true”, the second doens’t.
Ah, right. Thanks, I somehow missed that.
So the second is then implicitly assuming that physicalism is not true; it seems to me that the whole argument is basically a longwinded way of saying “I can’t imagine how consciousness can possibly be physical, therefore since I am conscious, physicalism is false”.
One might as easily imagine a world physically indistinguishable from ours, but in which there is no gravity, and thence conclude that gravity is not physical but somehow magical.
For some values of “imagine”. Given relativity, it would be pretty difficult to coheretly unplug gravity from mass, space and acceleration. It would be easier under Newton. I conclude that the unpluggabiliy of qualia means we just don’t have a relativity-grade eplanation of them, an explanation that makes them deeply interwoven with other things.
That seems like a reasonable conclusion to draw.
Not really. Just postulate something which does not have the same proportionality constant relating inertia to mass.
Inertia and mass are the same thing. You probably meant “the same proportionality constant between mass and gravitational force”, that is, imagine that the value of Newton’s constant G was different.
But this (like CCC’s grandparent post introducing the gravity analogy) actually goes in Chalmers’ favor. Insofar as we can coherently imagine a different value of G with all non-gravitational facts kept fixed, the actual value of G is a new “brute fact” about the universe that we cannot reduce to non-gravitational facts. The same goes for consciousness with respect to all physical facts, according to Chalmers. He explicitly compares consciousness to fundamental physical quantities like mass and electric charge.
The problem is that one aspect of the universe being conceptually irreducible at the moment (which is all that such thought experiments prove) does not imply it might forever remain so when fundamental theory changes, as Peterdjones says. Newton could imagine inertia without gravity at all, but after Einstein we can’t. Now we are able to imagine a different value of G, but maybe later we won’t (and I can actually sketch a plausible story of how this might come to happen if anyone is interested).
No, I meant a form of matter which coexisted with current forms of matter but which was accelerated by a force disproportionately to the amount of force exerted through the gravity force. One such possibility would be something that is ‘massless’ in that it isn’t accelerated by gravity but that has electric charge.
And by definition, the value of G is equal to 1, just like every other proportionality constant. I wasn’t postulating that MG/NS^2 have a different value.
Oooh, good one. I’m trying this if someone ever seriously tries to argue p-zombies with me.
Most versions of the Zombie Argument I’ve seen don’t specify that the world be physically identical to ours, merely indistinguishable.
http://en.wikipedia.org/wiki/Proof_by_contradiction
Agreed.
I’m being told that this is not the case, but I’m struggling to understand how.
I’m curious about your definition of “magical”. Is it the same as dualism)?
Within this discussion, I’ve tried to consistently use “magic” as meaning “not physics or logic”. Essentially, things that, given a perfect model of the (physical) universe that we live in, would be considered impossible or would go against all predictions for no cause that we can attribute to physics or logic or both.
So dualism is only one example, another could be intervention by the Lords of the Matrix (depending on how you draw boundaries for “universe that we live in”), and God or ontologically basic mental entities could be others.
So the assertion “we have something magical” is equivalent to “qualia is made of nonlogics” (although “nonlogics” is arguably still much more useful than “nonapples” as a conceptspace pointer).
Technically qualia is “non-physics”. Since if a human with a brain that does thinking is physics + logic, qualia is just the logic given the physics.
Errh, yes. Thank you. I think “nonlogics” is a decent fix, in light of this.
Errr, yes..that is the intended conclusion. But I don’t think you can say an argument is question begging beccause the intended conclusion follows from the premises taken jointly.
And how, pray tell, did they reach into the vast immense space of possible hypotheses and premises, and pluck out this one specific set of premises which just so happens that if you accept it completely, it inevitably must result in the conclusion that we have something magical granting us qualia?
The begging was done while choosing the premises, not in one of the premises individually.
Premise: All Bob Chairs must have seventy three thousand legs exactly.
Premise: Things we call chairs are illusions unless they are Bob Chairs.
Premise: None of the things we call chairs have exactly seventy three thousand legs.
Therefore, all of the things we call chairs are illusions and do not exist.
I seriously don’t see how the above argument is any more reasonable and any more or less question-begging than the p-zombie argument I’ve made in the grandparent. No single premise here assumes the conclusion, right? So no problem!
ETA: Perhaps it’s more clear if I just say that in order for the premises of the grandparent to be logically valid, one must also assume as a premise that having the information patterns of the human brain without creating qualia is possible in the first place. This is the key point that is the source of the question begging: It is assumed that the brain interactions do not create qualia, implicitly as part of the premises, otherwise the statement “P-zombies have the same brain interactions that we do but no qualia” is directly equivalent to “A → B, A, ¬B”.
So for A (brain interactions identical to us), B (possess qualia), and C (has magic):
(A → B) <==> ¬B → ¬A
((C → B) OR (AC → B)) <==> ¬(A → B)
A
¬B
Refactor to one single “question-begging” premise:
((((C ->B) OR (AC → B)) → C) <==> ¬(¬B → ¬A)) AND A AND ¬B
...therefore C.
I suppose they have the ability to formulate arguments that support their views. Are you saying that the honest way to argue is to fling premises together at random and see what happens?
Joint implication by premsies is validity not petitio principi.
That is an example of a True Scotsman fallacy, or argument by tendentious redefinition. I don’t see the parallel.
Eh. I’m bad at informal fallacies, apparently.
However, all they’ve done is pick specific premises that hide clever assumptions that logically must end up with their desired conclusion, without any reason in particular to believe that their premises make any sense. See the amateur logic I did in my edits of the grandparent.
It is very much assumed, by asserting the first, third and fourth premises, that qualia does not require brain interactions, as a prerequisite for positing the existence of p-zombies in the thought experiment.
Again: not assuming physicalism it not the same as assuming non-physicalism.
They assume (correctly) that if ¬B and A, then ¬(A → B)
Then they assume ¬B and A.
...
You’ve flattened out all the stuff about conceivability and logical possibility.
I have, but unfortunately that’s mostly because I don’t know the formal nomenclature and little details of writing conceivability and possibility logical statements.
I wouldn’t really trust myself to write formal logic with conceivability and probability without missing a step or strawmanning one of the premises at some point, with my currently very minimal understanding of that stuff.