I think that you are having trouble grasping this because there is no such thing as perfect certainty, and you are applying your realistic intuitions of fallibility to the idea—either that or I’m wrong!
Phlebas, like antigonus, I really enjoyed your essay (without agreeing with all of it). But the same objection that antigonus raises occurred to me. I’m not sure that you understood antigonus’s objection, so I will try to rephrase it in my words.
I follow you this far:
Now, the superintelligence is certain about your physical make-up, despite the fact that you are separate from it. … [I]t performs a computation, which it is certain is the same one occurring in your brain, …
And I agree that the superintelligence then experiences qualia. But what I don’t see is why
… when it experiences qualia it knows for certain that these qualia are caused by the computation.
Since you want to leave open the possibility that qualia are irreducible, you can’t assume that the superintelligence (SI) sees how the computation logically necessitates the generation of the qualia. The only alternative is that the SI reaches its conclusion through empirical observation. Indeed, this is how you describe the SI’s inference when you say,
When it doesn’t run the computation, it doesn’t get the qualia. When it runs it, it does.
But how can this kind of empirical observation provide that the SI with absolute certainty that the computation, and the computation alone, causes the qualia?
For example, how can the SI rule out the possibility that some nonphysical fact F applies to itself, but not to you (or the infant or whatever), and that [the computation + F] suffices to generate qualia, while [the computation—F] does not?
It seems that the SI has to leave open some small chance that, when it runs the computation, the computation generates qualia, but when you run the computation, you do not experience qualia because some additional nonphysical ingredient is missing. To deny this in a debate with Chalmers would seem to beg the question.
OK, a multi-paragraph summary first (skip it if you like; I feel it’s helpul to avoid any further arguing at cross-purposes) – since my position in the argument slowly morphed and became disorganised:
People claim to have “qualia”, which is different to mere Dennettian “consciousness” but can’t seemingly be defined. On examination of the brain, we will inevitably find some physical reason for why people discuss consciousness. It is highly improbable that this physical reason is unrelated to “qualia” OR “consciousness”. However, it is misleading to bundle these two together when discussing the subejct – and I do not accept the rather absurd claim that it’s OK to do so, because consciousness is a “confusion” – since arguments valid under certain assumptions about this “confusion” are not valid under other assumptions. In other words, Eliezer’s failure to attempt to distinguish reducible “qualia”, irreducible “qualia”, and qualia-eliminative “consciousness” as a preliminary step in his essay renders the essay liable to beg the question (question-begging seems to be the crux of the matter in general in this discussion) – unless he considers the irreducible qualia idea to be a priori nonsense.
If he does consider the irreducible qualia concept to be a priori nonsense:
a) Why not say so?
b) Why was such a misleadingly long essay necessary?
c) Why assume such a thing? OK, it doesn’t seem very Bayesian. But Bayes’s Theorem, Bayesian rationality and reductionism are just rules that apply perfectly to everything we’ve ever tried to apply them to – but in my ontology like most others’, there’s everything else and there’s qualia. There is no other concept, apart from “qualia”, that a supermajority of people affirm to be real in the absolute strongest terms – including people such as myself who are otherwise Bayesian reductionists – but which appears to be irreducible.
But anyhow, there is only an actual flaw in Eliezer’s refutation of Chalmer’s if we assume that “qualia” are real and irreducible. If qualia are real but irreducible, there must however be a reductionist causal explanation for physical humans discussing consciousness. I find the idea of our discovering a reductionist explanation of qualia, rather than mere consciousness, improbable. Therefore let us suppose that on examining the brain we discover a Dennettian causal explanation of our talking about consciousness, and then people are left to decide whether they accept this as a refutation of “qualia” or decide that such a belief is crazy and that qualia must be irreducible, existing apart from the physical cause of talk about consciousness.
Then, if we are not Dennettians we have very good reason still to believe that qualia supervene upon brain computations – presumably including the computations that constitute the physical reason for our discussing consciousness. Whatever happens to our brains physically, we experience our qualia changing synchronously and in qualitative relation. They may be “causally isolated” in the sense that we understand causality necessarily to involve reducible phenomena, but they “supervene” – when brain states change, qualia change likewise.
This distinction reveals the essentially question-begging nature of Eliezer’s talk about “causally closed outer Chalmers” being deranged – if we believe as seems to be the case that he dismisses the concept of irreduicble qualia out of hand. That is to say, the causal chain leading back from Chalmers’s hands typing on the keyboard about “qualia” leads precisely to the brain computations (viewed by other parts of the brain – per Dennett’s description) that are generating qualia – outer Chalmers is not deranged – but if we take a (somewhat) detailed look at a brain from outside, all we see is the brain examining itself in action; we might (naively?) assume that such a thing as “qualia” have been explained away. It’s only when a given brain apprehends another brain in sufficient detail (however much detail that may be) such that it is running approximately the selfsame computations, that it actually notices the qualia (like you said, in an empirical manner).
So, let us assume for the sake of argument that this belief is the accurate one regarding consciousness/qualia. I suspect that in believing in real, irreducible qualia I am somewhere between Eliezer’s and Chalmers’s stances, because it seems to me that Eliezer is not favourable towards such an idea, but pace Chalmers I do not consider there to be anything “extra-physical” about qualia – they are irreducible, but they supervene upon physical brain states therefore they are fully determined by mundane physical configurations of the Universe.
So, having tussled with Eliezer I still need to tussle with Chalmers. Perhaps Eliezer has done the job for me? Apparently not, because if we grant that there is a real, irreducible phenomenon “qualia”, Eliezer’s argument (if it applies at all) is simply that it’s improbable that humans would talk about having qualia, if they didn’t have qualia. This doesn’t prove that qualia are fully determined by physical configurations: seemingly a superintelligence that knows everything about some physical volume of the Universe is merely confident that beings inside (which do, in fact, experience qualia) have qualia.
Tyrrell, you are right in saying that I argue that the superintelligence concludes through empirical observation that these beings experience qualia.
You ask:
For example, how can the SI rule out the possibility that some nonphysical fact F applies to itself, but not to you (or the infant or whatever), and that [the computation + F] suffices to generate qualia, while [the computation—F] does not?
It seems that the SI has to leave open some small chance that, when it runs the computation, the computation generates qualia, but when you run the computation, you do not experience qualia because some additional nonphysical ingredient is missing. To deny this in a debate with Chalmers would seem to beg the question.
The superintelligence cannot rule that out. I agree, and I now understand Antigonus’s objection better too.
However, can it rule any “non-physical fact F” out? What about the non-physical fact F that its supposedly perfect knowledge about a certain volume of the Universe is bunkum? Is there any limitation to the purely physical knowledge that “non-physical facts” can potentially undermine – even in the eyes of a (physically) omniscient being?
If not, is it not unfair to apply this standard – having to rule out the possibility of some “non-physical fact” disrupting expectations – to the superintelligence’s knowledge of qualia, but not to its knowledge of everything else?
You may argue that this is question-begging. However, our objective is to prove that an omniscient superintelligence knows about qualia just as much as it knows about physical brains – assuming that (from our perspective, with extremely high probability) qualia do supervene on brain states (and also assuming that qualia are real and irreducible, to make the discussion meaningful). And we have proven that: what the superintelligence, as an omniscient mind, does is effectively to take physical brains, inhabit them and see if they experience qualia.
If this wasn’t the case – if we were stumped: “Um yeah, I don’t see how this superintelligence knows if I have qualia” – then we might have to concede the point to Chalmers. It would appear that qualia were not fully determined by physical configurations, therefore they must be “extra-physical” rather supervening on brain states and being merely irreducible.
The difference is that the “non-physical fact” that you speak of is equally capable of undermining anything. It is fully general. If we were arguing with Chalmers about whether there are “non-physical facts” in general then I would be begging the question – that seems an a priori irresolvable argument. But what we are actually arguing about is whether we are forced to admit a specific, apparent gap in physics where a real phenomenon is seen to lack a physical underpinning. This would prove that there is at least one “non-physical fact”. In other words, we are not trying to prove the non-existence of non-physical facts in general (heaven forbid!) but merely to disprove the idea that there is any particular reason why we should believe that there are any non-physical facts.
Phlebas, like antigonus, I really enjoyed your essay (without agreeing with all of it). But the same objection that antigonus raises occurred to me. I’m not sure that you understood antigonus’s objection, so I will try to rephrase it in my words.
I follow you this far:
And I agree that the superintelligence then experiences qualia. But what I don’t see is why
Since you want to leave open the possibility that qualia are irreducible, you can’t assume that the superintelligence (SI) sees how the computation logically necessitates the generation of the qualia. The only alternative is that the SI reaches its conclusion through empirical observation. Indeed, this is how you describe the SI’s inference when you say,
But how can this kind of empirical observation provide that the SI with absolute certainty that the computation, and the computation alone, causes the qualia?
For example, how can the SI rule out the possibility that some nonphysical fact F applies to itself, but not to you (or the infant or whatever), and that [the computation + F] suffices to generate qualia, while [the computation—F] does not?
It seems that the SI has to leave open some small chance that, when it runs the computation, the computation generates qualia, but when you run the computation, you do not experience qualia because some additional nonphysical ingredient is missing. To deny this in a debate with Chalmers would seem to beg the question.
OK, a multi-paragraph summary first (skip it if you like; I feel it’s helpul to avoid any further arguing at cross-purposes) – since my position in the argument slowly morphed and became disorganised:
People claim to have “qualia”, which is different to mere Dennettian “consciousness” but can’t seemingly be defined. On examination of the brain, we will inevitably find some physical reason for why people discuss consciousness. It is highly improbable that this physical reason is unrelated to “qualia” OR “consciousness”. However, it is misleading to bundle these two together when discussing the subejct – and I do not accept the rather absurd claim that it’s OK to do so, because consciousness is a “confusion” – since arguments valid under certain assumptions about this “confusion” are not valid under other assumptions. In other words, Eliezer’s failure to attempt to distinguish reducible “qualia”, irreducible “qualia”, and qualia-eliminative “consciousness” as a preliminary step in his essay renders the essay liable to beg the question (question-begging seems to be the crux of the matter in general in this discussion) – unless he considers the irreducible qualia idea to be a priori nonsense.
If he does consider the irreducible qualia concept to be a priori nonsense:
a) Why not say so?
b) Why was such a misleadingly long essay necessary?
c) Why assume such a thing? OK, it doesn’t seem very Bayesian. But Bayes’s Theorem, Bayesian rationality and reductionism are just rules that apply perfectly to everything we’ve ever tried to apply them to – but in my ontology like most others’, there’s everything else and there’s qualia. There is no other concept, apart from “qualia”, that a supermajority of people affirm to be real in the absolute strongest terms – including people such as myself who are otherwise Bayesian reductionists – but which appears to be irreducible.
But anyhow, there is only an actual flaw in Eliezer’s refutation of Chalmer’s if we assume that “qualia” are real and irreducible. If qualia are real but irreducible, there must however be a reductionist causal explanation for physical humans discussing consciousness. I find the idea of our discovering a reductionist explanation of qualia, rather than mere consciousness, improbable. Therefore let us suppose that on examining the brain we discover a Dennettian causal explanation of our talking about consciousness, and then people are left to decide whether they accept this as a refutation of “qualia” or decide that such a belief is crazy and that qualia must be irreducible, existing apart from the physical cause of talk about consciousness.
Then, if we are not Dennettians we have very good reason still to believe that qualia supervene upon brain computations – presumably including the computations that constitute the physical reason for our discussing consciousness. Whatever happens to our brains physically, we experience our qualia changing synchronously and in qualitative relation. They may be “causally isolated” in the sense that we understand causality necessarily to involve reducible phenomena, but they “supervene” – when brain states change, qualia change likewise.
This distinction reveals the essentially question-begging nature of Eliezer’s talk about “causally closed outer Chalmers” being deranged – if we believe as seems to be the case that he dismisses the concept of irreduicble qualia out of hand. That is to say, the causal chain leading back from Chalmers’s hands typing on the keyboard about “qualia” leads precisely to the brain computations (viewed by other parts of the brain – per Dennett’s description) that are generating qualia – outer Chalmers is not deranged – but if we take a (somewhat) detailed look at a brain from outside, all we see is the brain examining itself in action; we might (naively?) assume that such a thing as “qualia” have been explained away. It’s only when a given brain apprehends another brain in sufficient detail (however much detail that may be) such that it is running approximately the selfsame computations, that it actually notices the qualia (like you said, in an empirical manner).
So, let us assume for the sake of argument that this belief is the accurate one regarding consciousness/qualia. I suspect that in believing in real, irreducible qualia I am somewhere between Eliezer’s and Chalmers’s stances, because it seems to me that Eliezer is not favourable towards such an idea, but pace Chalmers I do not consider there to be anything “extra-physical” about qualia – they are irreducible, but they supervene upon physical brain states therefore they are fully determined by mundane physical configurations of the Universe.
So, having tussled with Eliezer I still need to tussle with Chalmers. Perhaps Eliezer has done the job for me? Apparently not, because if we grant that there is a real, irreducible phenomenon “qualia”, Eliezer’s argument (if it applies at all) is simply that it’s improbable that humans would talk about having qualia, if they didn’t have qualia. This doesn’t prove that qualia are fully determined by physical configurations: seemingly a superintelligence that knows everything about some physical volume of the Universe is merely confident that beings inside (which do, in fact, experience qualia) have qualia.
Tyrrell, you are right in saying that I argue that the superintelligence concludes through empirical observation that these beings experience qualia.
You ask:
The superintelligence cannot rule that out. I agree, and I now understand Antigonus’s objection better too. However, can it rule any “non-physical fact F” out? What about the non-physical fact F that its supposedly perfect knowledge about a certain volume of the Universe is bunkum? Is there any limitation to the purely physical knowledge that “non-physical facts” can potentially undermine – even in the eyes of a (physically) omniscient being?
If not, is it not unfair to apply this standard – having to rule out the possibility of some “non-physical fact” disrupting expectations – to the superintelligence’s knowledge of qualia, but not to its knowledge of everything else?
You may argue that this is question-begging. However, our objective is to prove that an omniscient superintelligence knows about qualia just as much as it knows about physical brains – assuming that (from our perspective, with extremely high probability) qualia do supervene on brain states (and also assuming that qualia are real and irreducible, to make the discussion meaningful). And we have proven that: what the superintelligence, as an omniscient mind, does is effectively to take physical brains, inhabit them and see if they experience qualia.
If this wasn’t the case – if we were stumped: “Um yeah, I don’t see how this superintelligence knows if I have qualia” – then we might have to concede the point to Chalmers. It would appear that qualia were not fully determined by physical configurations, therefore they must be “extra-physical” rather supervening on brain states and being merely irreducible.
The difference is that the “non-physical fact” that you speak of is equally capable of undermining anything. It is fully general. If we were arguing with Chalmers about whether there are “non-physical facts” in general then I would be begging the question – that seems an a priori irresolvable argument. But what we are actually arguing about is whether we are forced to admit a specific, apparent gap in physics where a real phenomenon is seen to lack a physical underpinning. This would prove that there is at least one “non-physical fact”. In other words, we are not trying to prove the non-existence of non-physical facts in general (heaven forbid!) but merely to disprove the idea that there is any particular reason why we should believe that there are any non-physical facts.