Why Zombies Pose a Problem to Type-B (Identity Theorist) Materialists
This is the second and final section of my presentation, as promised. It's a bit long, but I figured it is best not split up. My presentation was on the shortcomings of Andy Clark's book Mindware, insofar as it fails to take the hard problem seriously. I've omitted most of my discussion of Clark, and skipped to the final section on zombies and modality. Here it is.
Chalmers’ Conceivability Argument, or as it is more popularly called, the Zombie Argument, does indeed pose a problem, perhaps even an intractable one, to a materialist conception of mind, albeit, one that takes phenomenal consciousness seriously. The goal of this paper is to show what Clark left out in failing to treat the hard problem seriously and why it should have been afforded a more prominent role in his book, if it is not clear already.
The type-B materialist’s rejection of the Zombie Argument, aside from the fact that it may have negative Hollywood movie connotations, is a result of a failure to fully understand or appreciate the semantic engine that Chalmers sets in place in order to make this modal argument clear. Before detailing its finer grain, I’ll first offer it in its basic construction and then provide a brief explanation of the two dimensional semantics that make the second version more compelling.
The rough idea is that it I can conceive a molecule-for-molecule physical duplicate of myself that is identical to me not only in its material constitution but also in its behavior and reactions to various stimuli. The only thing that separates Alden from zombie-Alden is a full-night’s sleep, or, to be serious, phenomenal consciousness or qualia. There is nothing that it is like to be zombie-Alden. To make it more perspicuous, here is a formalization of Chalmers’ argument. It is important to note that it’s not necessary that there be a full-blown zombie-Alden; a partial zombie or someone with inverted qualia serves the argument just as well. Let P be the conjunction of all microphysical truths about the universe and Q be a phenomenal truth, either that someone is phenomenally conscious or that someone instantiates a particular phenomenal property.
(1) P&~Q is conceivable
(2) If P&~Q is conceivable, P&~Q is metaphysically possible
(3) If P&~Q is metaphysically possible, materialism is false.
________
(4) Materialism is false (Chalmers, 2005).
Premise (1) makes an epistemic claim about what is conceivable. Premise (2) makes a modal claim about what is possible. Premise (3) makes a metaphysical claim about the nature of the world. The question is whether Chalmers has license to infer (2) from (1) and (3) from (2), because it is not clear that conceivability entails possibility in all cases, nor is it clear that just because something is possible in one world we will be able to make a claim that is necessary in all possible worlds.
First, to treat the link between conceivability and possibility. Chalmers defends the idea that if something is conceivable it is possible, but he frames conceivability in two senses, prima facie and ideal. Ideal conceivability is the best guide to possibility because when we conceive of X ideally we do so as an ideally rational agent capable of spotting any contradiction or incoherence resulting from the conception of a possible world in which X is instantiated. To enumerate some of Chalmers’ examples ‘1+1=3’ is neither prima facie nor ideally conceivable, whereas a highly complex mathematical truth may be prima facie conceivable as ~X but it is not ideally conceivable. In addition, there are two kinds of conceivability, positive and negative. Negative conceivability simply involves X not being ruled out a priori by a priori reasoning, whereas positive conceivability is linked to the act of imagination. For the purposes of his argument, Chalmers makes use of ideal conceivability, as it serves as a better guide to possibility. The choice between positive and negative conceivability is of no consequence to the status of his general argument.
There are counterexamples to Chalmers’ conceivability entails possibility thesis, and they are offered by Kripke, but Chalmers shows that on closer inspection lessons learned from Kripke actually bolster his zombie argument. Some may argue that ‘water is not H2O’ is an example something that is conceivable but metaphysically impossible. This threatens the link between conceivability and possibility that Chalmers is trying to defend.
If we understand ‘conceivable’ in counterfactual terms, then we may be inclined to say that ‘water is not H2O’ is not only impossible but inconceivable. For in our world, the actual world, water is H20, so if we imagine a distant planet that is materially identical to Earth in every way, with three quarters of its surface covered by a life-giving liquid, but that liquid is not H2O but XYZ, we could not call that substance water, because water is necessarily H2O. At most we could call it ‘watery-stuff.’ In this case, we could suppose that ‘water is not H2O is prima facie conceivable, but upon further reflection ‘water is not H2O’ is inconceivable. This sense of conceivable is done in light of how we know things are in the actual world. Chalmers calls it secondary conceivability and the intensions that accompany the meanings of its terms are secondary intensions and the possibilities it treats are secondarily possible or for short, 2-possible. Those who reject Chalmers zombie argument may do so on the grounds that eventually they believe that science will allow for the a posteriori identity of the phenomenal and the physical realm in the same why as it has offered an a posteriori identity of water and H2O.
Primary conceivability is conceivability understood in the a priori sense. In this sense, we can conceive ‘water is not H2O,’ because, obviously, ‘water is not H2O’ cannot be established a priori. When one conceives of a possible world in the primary sense one conceives of that world not as counterfactual, but as actual. So if I imagine a world in which ‘water is XYZ’ is true in the actual world I inhabit, then I should rationally conclude that ‘water is XYZ, not H2O.’ Water is XYZ is not 2-possible, but it is 1-possible, meaning that insofar as we can accept or pretend that in our world water is XYZ, then we can endorse the statement that ‘water is not H2O.’ Chalmers grants that this is not the traditional way possible worlds are understood, but he makes a case that his understanding, though it may be different from Kripke’s notion of modality, is both compatible and compelling.
While ‘water is not H2O’ is inconceivable in the counterfactual (subjunctive), or secondary sense, in these terms Chalmers shows that it is conceivable in the actual or a priori sense. Hence we have a good reason to believe that 1-conceivability and 1-possibility and 2-conceivability and 2-possibility are linked. With these new concepts in mind, we may provide a refined version of Chalmers’ conceivability argument.
(1) P&~Q is conceivable
(2) If P&~Q is conceivable, P&~Q is 1-possible
(3) If P&~Q is 1-possible, materialism is false.
_______________
(4) Materialism is false (Chalmers 2005).
It is easy to see why this will not work because it fails to adequately describe materialism, for the materialists claim that P entails Q invokes metaphysical possibility, that is, that inevitably we will achieve an a posteriori identity between phenomenal properties and physical properties, such that P implies Q in the same way that water implies H2O. Hence, the denial of materialism requires that we invoke secondary possibility, such that it could not be otherwise that P fails to imply Q.
In order for this argument to work, Chalmers explains that we have to close the gap between the primary and secondary dimensions of conceivability and possibility. “In the case of Q, this claim is quite plausible. As Kripke noted, there does not seem to be the same strong dissociation between appearance and reality in the case of consciousness as in the cases of water and heat: while it is not the case that anything that looks like water is water, or that anything that feels like heat is heat, it is plausibly the case that anything that feels like consciousness is consciousness.” (Chalmers, 2005)
In the case of P, this is less likely to work. The materialist may argue that the primary and secondary intensions refer to different things in the microphysical realm. It is plausible that the primary intensions of our microphysical terms refer to the things that play the various theoretical roles of such things as ‘mass’ and ‘charge,’ whereas the secondary intensions of our microphysical terms will refer to the intrinsic properties that play such roles. On this account we may say that to verify P, a world must have the right structural profile, while to satisfy P, a world must have the right structural and intrinsic profile (Chalmers, 2005).
With this in mind, we can offer the final version of Chalmers’ Conceivability Argument:
1) P&~Q is conceivable
(2) If P&~Q is conceivable, then P&~Q is 1-possible
(3) If P&~Q is 1-possible, then P&~Q is 2-possible or Russellian monism is true.
(4) If P&~Q is 2-possible, materialism is false.
_______________
(5) Materialism is false or Russellian monism is true (Chalmers 2005).
As we can see in the inference from premise (2) to (3) we can collapse the 1-possibility of not-Q into 2-possibility, but it is not necessarily the case that we can do the same with P. Although we can imagine a priori a world that provides epistemic verification for all the functional roles played by the concepts of physics, it is not necessary that the intrinsic properties of the substances that instantiate those roles will be identical with those in our own world. Thus, Chalmers leaves open the door for some sort of panprotopsychical constituents, unlike anything known to contemporary microphysics, that promise to bridge the gap between the phenomenal and the physical realms.
Are there really two dimensions operating in Chalmers argument? It seems that his first, a priori, non-counterfactual account of the actual world being conceivably different than our own is really just another counterfactual world. If we pretend that we do not know that such and such are facts, then we can conceive of X differently, but is it really possible to conceive of X differently if we already know that it is necessary a posteriori, such as in the case of water being H2O?
What can be said in criticism of Chalmers, however, is that Russellian monism sounds just as hopeless as the traditional materialist views. On the other hand, in Chalmers’ defense, it is not conceptually doomed from the start like the other positions, and with lack of any viable competing positions, it is the one we are forced to accept.
Clark is unconvinced by Chalmers’ Zombie Argument. He argues that possibilities should have no bearing on the faith in how things work in the actual world, we should not let Chalmers’ Zombies allow us to worry anymore about consciousness posing a hard problem to cognitive science anymore than we worry about “remote control zombies” (channel changers that don’t change channels in other logically possible worlds) posing a problem to our successfully using a real world channel changer (Clark, 187). What Clark fails to see is that Chalmers’ argument is not drawn from just any logically possible but world, but from considerations relevant to the actual world, and his objection to Chalmers is both trivial and shows a shallow understanding of what is at stake.
Chalmers’ Conceivability Argument, or as it is more popularly called, the Zombie Argument, does indeed pose a problem, perhaps even an intractable one, to a materialist conception of mind, albeit, one that takes phenomenal consciousness seriously. The goal of this paper is to show what Clark left out in failing to treat the hard problem seriously and why it should have been afforded a more prominent role in his book, if it is not clear already.
The type-B materialist’s rejection of the Zombie Argument, aside from the fact that it may have negative Hollywood movie connotations, is a result of a failure to fully understand or appreciate the semantic engine that Chalmers sets in place in order to make this modal argument clear. Before detailing its finer grain, I’ll first offer it in its basic construction and then provide a brief explanation of the two dimensional semantics that make the second version more compelling.
The rough idea is that it I can conceive a molecule-for-molecule physical duplicate of myself that is identical to me not only in its material constitution but also in its behavior and reactions to various stimuli. The only thing that separates Alden from zombie-Alden is a full-night’s sleep, or, to be serious, phenomenal consciousness or qualia. There is nothing that it is like to be zombie-Alden. To make it more perspicuous, here is a formalization of Chalmers’ argument. It is important to note that it’s not necessary that there be a full-blown zombie-Alden; a partial zombie or someone with inverted qualia serves the argument just as well. Let P be the conjunction of all microphysical truths about the universe and Q be a phenomenal truth, either that someone is phenomenally conscious or that someone instantiates a particular phenomenal property.
(1) P&~Q is conceivable
(2) If P&~Q is conceivable, P&~Q is metaphysically possible
(3) If P&~Q is metaphysically possible, materialism is false.
________
(4) Materialism is false (Chalmers, 2005).
Premise (1) makes an epistemic claim about what is conceivable. Premise (2) makes a modal claim about what is possible. Premise (3) makes a metaphysical claim about the nature of the world. The question is whether Chalmers has license to infer (2) from (1) and (3) from (2), because it is not clear that conceivability entails possibility in all cases, nor is it clear that just because something is possible in one world we will be able to make a claim that is necessary in all possible worlds.
First, to treat the link between conceivability and possibility. Chalmers defends the idea that if something is conceivable it is possible, but he frames conceivability in two senses, prima facie and ideal. Ideal conceivability is the best guide to possibility because when we conceive of X ideally we do so as an ideally rational agent capable of spotting any contradiction or incoherence resulting from the conception of a possible world in which X is instantiated. To enumerate some of Chalmers’ examples ‘1+1=3’ is neither prima facie nor ideally conceivable, whereas a highly complex mathematical truth may be prima facie conceivable as ~X but it is not ideally conceivable. In addition, there are two kinds of conceivability, positive and negative. Negative conceivability simply involves X not being ruled out a priori by a priori reasoning, whereas positive conceivability is linked to the act of imagination. For the purposes of his argument, Chalmers makes use of ideal conceivability, as it serves as a better guide to possibility. The choice between positive and negative conceivability is of no consequence to the status of his general argument.
There are counterexamples to Chalmers’ conceivability entails possibility thesis, and they are offered by Kripke, but Chalmers shows that on closer inspection lessons learned from Kripke actually bolster his zombie argument. Some may argue that ‘water is not H2O’ is an example something that is conceivable but metaphysically impossible. This threatens the link between conceivability and possibility that Chalmers is trying to defend.
If we understand ‘conceivable’ in counterfactual terms, then we may be inclined to say that ‘water is not H2O’ is not only impossible but inconceivable. For in our world, the actual world, water is H20, so if we imagine a distant planet that is materially identical to Earth in every way, with three quarters of its surface covered by a life-giving liquid, but that liquid is not H2O but XYZ, we could not call that substance water, because water is necessarily H2O. At most we could call it ‘watery-stuff.’ In this case, we could suppose that ‘water is not H2O is prima facie conceivable, but upon further reflection ‘water is not H2O’ is inconceivable. This sense of conceivable is done in light of how we know things are in the actual world. Chalmers calls it secondary conceivability and the intensions that accompany the meanings of its terms are secondary intensions and the possibilities it treats are secondarily possible or for short, 2-possible. Those who reject Chalmers zombie argument may do so on the grounds that eventually they believe that science will allow for the a posteriori identity of the phenomenal and the physical realm in the same why as it has offered an a posteriori identity of water and H2O.
Primary conceivability is conceivability understood in the a priori sense. In this sense, we can conceive ‘water is not H2O,’ because, obviously, ‘water is not H2O’ cannot be established a priori. When one conceives of a possible world in the primary sense one conceives of that world not as counterfactual, but as actual. So if I imagine a world in which ‘water is XYZ’ is true in the actual world I inhabit, then I should rationally conclude that ‘water is XYZ, not H2O.’ Water is XYZ is not 2-possible, but it is 1-possible, meaning that insofar as we can accept or pretend that in our world water is XYZ, then we can endorse the statement that ‘water is not H2O.’ Chalmers grants that this is not the traditional way possible worlds are understood, but he makes a case that his understanding, though it may be different from Kripke’s notion of modality, is both compatible and compelling.
While ‘water is not H2O’ is inconceivable in the counterfactual (subjunctive), or secondary sense, in these terms Chalmers shows that it is conceivable in the actual or a priori sense. Hence we have a good reason to believe that 1-conceivability and 1-possibility and 2-conceivability and 2-possibility are linked. With these new concepts in mind, we may provide a refined version of Chalmers’ conceivability argument.
(1) P&~Q is conceivable
(2) If P&~Q is conceivable, P&~Q is 1-possible
(3) If P&~Q is 1-possible, materialism is false.
_______________
(4) Materialism is false (Chalmers 2005).
It is easy to see why this will not work because it fails to adequately describe materialism, for the materialists claim that P entails Q invokes metaphysical possibility, that is, that inevitably we will achieve an a posteriori identity between phenomenal properties and physical properties, such that P implies Q in the same way that water implies H2O. Hence, the denial of materialism requires that we invoke secondary possibility, such that it could not be otherwise that P fails to imply Q.
In order for this argument to work, Chalmers explains that we have to close the gap between the primary and secondary dimensions of conceivability and possibility. “In the case of Q, this claim is quite plausible. As Kripke noted, there does not seem to be the same strong dissociation between appearance and reality in the case of consciousness as in the cases of water and heat: while it is not the case that anything that looks like water is water, or that anything that feels like heat is heat, it is plausibly the case that anything that feels like consciousness is consciousness.” (Chalmers, 2005)
In the case of P, this is less likely to work. The materialist may argue that the primary and secondary intensions refer to different things in the microphysical realm. It is plausible that the primary intensions of our microphysical terms refer to the things that play the various theoretical roles of such things as ‘mass’ and ‘charge,’ whereas the secondary intensions of our microphysical terms will refer to the intrinsic properties that play such roles. On this account we may say that to verify P, a world must have the right structural profile, while to satisfy P, a world must have the right structural and intrinsic profile (Chalmers, 2005).
With this in mind, we can offer the final version of Chalmers’ Conceivability Argument:
1) P&~Q is conceivable
(2) If P&~Q is conceivable, then P&~Q is 1-possible
(3) If P&~Q is 1-possible, then P&~Q is 2-possible or Russellian monism is true.
(4) If P&~Q is 2-possible, materialism is false.
_______________
(5) Materialism is false or Russellian monism is true (Chalmers 2005).
As we can see in the inference from premise (2) to (3) we can collapse the 1-possibility of not-Q into 2-possibility, but it is not necessarily the case that we can do the same with P. Although we can imagine a priori a world that provides epistemic verification for all the functional roles played by the concepts of physics, it is not necessary that the intrinsic properties of the substances that instantiate those roles will be identical with those in our own world. Thus, Chalmers leaves open the door for some sort of panprotopsychical constituents, unlike anything known to contemporary microphysics, that promise to bridge the gap between the phenomenal and the physical realms.
Are there really two dimensions operating in Chalmers argument? It seems that his first, a priori, non-counterfactual account of the actual world being conceivably different than our own is really just another counterfactual world. If we pretend that we do not know that such and such are facts, then we can conceive of X differently, but is it really possible to conceive of X differently if we already know that it is necessary a posteriori, such as in the case of water being H2O?
What can be said in criticism of Chalmers, however, is that Russellian monism sounds just as hopeless as the traditional materialist views. On the other hand, in Chalmers’ defense, it is not conceptually doomed from the start like the other positions, and with lack of any viable competing positions, it is the one we are forced to accept.
Clark is unconvinced by Chalmers’ Zombie Argument. He argues that possibilities should have no bearing on the faith in how things work in the actual world, we should not let Chalmers’ Zombies allow us to worry anymore about consciousness posing a hard problem to cognitive science anymore than we worry about “remote control zombies” (channel changers that don’t change channels in other logically possible worlds) posing a problem to our successfully using a real world channel changer (Clark, 187). What Clark fails to see is that Chalmers’ argument is not drawn from just any logically possible but world, but from considerations relevant to the actual world, and his objection to Chalmers is both trivial and shows a shallow understanding of what is at stake.