Daniel Dennett fails to fight off the attack of backwards-walking zombies; or reverse psychology is no psychology at all
[I haven't decided whether or not this is a keeper]
Daniel Dennett says it's simply impossible that there be a philosophical zombie, i.e., a creature that acts just like humans even at the neuronal level but has no consciousness. I agree but would add that IF reductive physicalism were true, then such creatures could exist, and in that case consciousness itself would be causally superfluous.
In order to show the truth of the hypothetical statement in italics, I propose that you apply one of the properties of reductive physicalism called reversibility to the scenario in which communication is used to direct behavior. I propose, furthermore, that to make this point we use (a modified version of) the example used by Dennett to show that consciousness is not superfluous. Suppose there are three individuals, Nestor speaks Navajo and English; Engelbert, who speaks only English, and Seth, who can understand English and Swedish. Nestor can see a pair of lights (one green, the other red) which neither of the other two can see. When Nestor sees a green light illuminate, his job is to say find a truth that he can communicate to Engelbert. So he consults a Navaho language fact book, finds a truth, and then communicates it in English to Englebert alone so that Seth doesn't hear it. Englebert in turn says the same truth to Seth alone, and does so in a way that does not allow Nestor to hear it. Upon hearing it, Seth consults his fact book, written in Swedish, to find out whether it is true or false. Upon discovering that it is true (or at least purportedly true), Seth presses a green light that neither Nestor nor Englebert can see. When Nestor sees a red light, however, he uses his fact book to generate a claim that according to his fact book is false. He transmits this false claim to Englebert in the same manner, who in turn shares it with Seth, who --upon checking his Swedish language fact book -- determines that it is false and presses the button for the red light. Neither Nestor nor Englebert can see the color of the light that Seth has illuminated, but those monitoring the experiment can see both Nestor's and Seth's lights and thereby check how it is going.
Let's apply the concept of reversibility to the above scenario. According to reductive materialists such as Sean Carol, all processes are reversible. That is any process occurring in nature (including the intercommunication between Nestor, Englebert and Seth) can be perfectly reversed while following the same physical laws. As Carol points out, change is like a movie that can be played in reverse. This position follows necessarily from reductive materialism. So let us consider what will happen when the process described above has been reversed.
According to reductive materialism, for every process, there is the possibility of a mirror image process, which I'll call a "regress." So even though it may be improbable, it is possible in principle that the communicative process between Nestor, Englebert and Seth occur in reverse. This regress, however, is devoid of meaning-acts. Cognition, therefore, is not needed for that regress to occur. But if cognition is not needed for the regress, it would seem to be superfluous to the original process. For when working in reverse, Nestor, Englebert and Seth are zombie-like, albeit not precisely the sorts of zombies that Dennett says are impossible. They are possible if reductive physicalism is true, for reductive physicalism also entails reversibility.
[the fact that the regressive versions of Seth, Englebert and Nestor don't act like us may or may not make the argument lame. But there is potential here: the lack of aboutness in the regress is interesting… worth considering further. It at least provokes one to wonder why process should involve aboutness while regress doesn't? Back to the original post]
We might add another point. According to reductive physicalism, the communicative process originally described is, by a double reversal, identical with three zombies working in reverse. Cognition would therefore seem to be superfluous.
One might object that communication is happening in the regress but it is of a different sort--perhaps the sort that might motivate the reverse communication (from Seth to Nestor rather than from Nestor to Seth). Just as people seem to walk backwards when a movie is played in reverse, so too their cognitive acts occur in reverse order and this somehow guides the reverse version of the communicative process. But Englebert does not perceive the color of the light pressed by Seth; nor does Nestor hear what Englebert says. No communication takes place in the regress.
Nor does any cognition take place in the regress. This point becomes clear when we compare the reversal of the firing of a neuron (mention action potential, axon hillock, etc) to the reversal of the hammering of a nail. While the hammering of a nail (playing the movie forwards) involves the swinging of a hammer to bring force upon a nail, which pushes it down. The reverse, opposite process consists of a nail rising energetically from the wood (all of this happens in a manner consistent with the laws of nature), pushing the hammer up with great force, etc. Neurons operating in reverse no more fire (We might call the process "erif"-ing instead of firing) than a hammer that is pushed up by a nail is said to push the nails down. Since the neural regress is not a firing, it would seem that the higher level neural operations lack the appropriate foundation. Like the neural "erif"-ing, these higher level operations are no more like cognition than a nail pushing up a hammer is like the hammering of a nail. And since the laws of physics sans cognition suffice to account for what happens regress, it seems that the same might as well be true when it is played forward. In other words, when followed to its logical conclusion, leads to eliminative materialism (or perhaps epiphenomenalism). In other words, the "syntax" of physics suffices in the absence of the "semantics" of any meaning-acts (desire, intention hope, deliberation, endeavor, satisfaction with what one has done).
If meaning acts are missing but not missed (i.e., not needed) when a sequence of events happening in our world is played in reverse, then they are superfluous when the world moves forwards.
[this argument might not be lame: not sure. What the two above attempted arguments need is a theorem regarding the equivalence between the process and regress. A hammer pushing down a nail and a nail pushing up a hammer both involve pushing as a source of change. Equivalent, sort of. An explosion and an implosion. Are they equivalent in any sense of the term? Cream dispersing into coffee and cream and coffee separating from each other: are they equivalent too? Perhaps if one postulates that there is nothing to processes but the interaction of forces and that process/regress forces are equivalent?]
The real problem is that the design stance and intentional stance, as described by DD, involve a kind of cheating that allows DD to import "something more" without clearly clarifying whether this "more" is subjective or objective. I think that if one asked that question and pursued both possibilities, then one might be able to come up with a destructive dilemma.
Daniel Dennett says it's simply impossible that there be a philosophical zombie, i.e., a creature that acts just like humans even at the neuronal level but has no consciousness. I agree but would add that IF reductive physicalism were true, then such creatures could exist, and in that case consciousness itself would be causally superfluous.
In order to show the truth of the hypothetical statement in italics, I propose that you apply one of the properties of reductive physicalism called reversibility to the scenario in which communication is used to direct behavior. I propose, furthermore, that to make this point we use (a modified version of) the example used by Dennett to show that consciousness is not superfluous. Suppose there are three individuals, Nestor speaks Navajo and English; Engelbert, who speaks only English, and Seth, who can understand English and Swedish. Nestor can see a pair of lights (one green, the other red) which neither of the other two can see. When Nestor sees a green light illuminate, his job is to say find a truth that he can communicate to Engelbert. So he consults a Navaho language fact book, finds a truth, and then communicates it in English to Englebert alone so that Seth doesn't hear it. Englebert in turn says the same truth to Seth alone, and does so in a way that does not allow Nestor to hear it. Upon hearing it, Seth consults his fact book, written in Swedish, to find out whether it is true or false. Upon discovering that it is true (or at least purportedly true), Seth presses a green light that neither Nestor nor Englebert can see. When Nestor sees a red light, however, he uses his fact book to generate a claim that according to his fact book is false. He transmits this false claim to Englebert in the same manner, who in turn shares it with Seth, who --upon checking his Swedish language fact book -- determines that it is false and presses the button for the red light. Neither Nestor nor Englebert can see the color of the light that Seth has illuminated, but those monitoring the experiment can see both Nestor's and Seth's lights and thereby check how it is going.
Let's apply the concept of reversibility to the above scenario. According to reductive materialists such as Sean Carol, all processes are reversible. That is any process occurring in nature (including the intercommunication between Nestor, Englebert and Seth) can be perfectly reversed while following the same physical laws. As Carol points out, change is like a movie that can be played in reverse. This position follows necessarily from reductive materialism. So let us consider what will happen when the process described above has been reversed.
According to reductive materialism, for every process, there is the possibility of a mirror image process, which I'll call a "regress." So even though it may be improbable, it is possible in principle that the communicative process between Nestor, Englebert and Seth occur in reverse. This regress, however, is devoid of meaning-acts. Cognition, therefore, is not needed for that regress to occur. But if cognition is not needed for the regress, it would seem to be superfluous to the original process. For when working in reverse, Nestor, Englebert and Seth are zombie-like, albeit not precisely the sorts of zombies that Dennett says are impossible. They are possible if reductive physicalism is true, for reductive physicalism also entails reversibility.
[the fact that the regressive versions of Seth, Englebert and Nestor don't act like us may or may not make the argument lame. But there is potential here: the lack of aboutness in the regress is interesting… worth considering further. It at least provokes one to wonder why process should involve aboutness while regress doesn't? Back to the original post]
We might add another point. According to reductive physicalism, the communicative process originally described is, by a double reversal, identical with three zombies working in reverse. Cognition would therefore seem to be superfluous.
One might object that communication is happening in the regress but it is of a different sort--perhaps the sort that might motivate the reverse communication (from Seth to Nestor rather than from Nestor to Seth). Just as people seem to walk backwards when a movie is played in reverse, so too their cognitive acts occur in reverse order and this somehow guides the reverse version of the communicative process. But Englebert does not perceive the color of the light pressed by Seth; nor does Nestor hear what Englebert says. No communication takes place in the regress.
Nor does any cognition take place in the regress. This point becomes clear when we compare the reversal of the firing of a neuron (mention action potential, axon hillock, etc) to the reversal of the hammering of a nail. While the hammering of a nail (playing the movie forwards) involves the swinging of a hammer to bring force upon a nail, which pushes it down. The reverse, opposite process consists of a nail rising energetically from the wood (all of this happens in a manner consistent with the laws of nature), pushing the hammer up with great force, etc. Neurons operating in reverse no more fire (We might call the process "erif"-ing instead of firing) than a hammer that is pushed up by a nail is said to push the nails down. Since the neural regress is not a firing, it would seem that the higher level neural operations lack the appropriate foundation. Like the neural "erif"-ing, these higher level operations are no more like cognition than a nail pushing up a hammer is like the hammering of a nail. And since the laws of physics sans cognition suffice to account for what happens regress, it seems that the same might as well be true when it is played forward. In other words, when followed to its logical conclusion, leads to eliminative materialism (or perhaps epiphenomenalism). In other words, the "syntax" of physics suffices in the absence of the "semantics" of any meaning-acts (desire, intention hope, deliberation, endeavor, satisfaction with what one has done).
If meaning acts are missing but not missed (i.e., not needed) when a sequence of events happening in our world is played in reverse, then they are superfluous when the world moves forwards.
[this argument might not be lame: not sure. What the two above attempted arguments need is a theorem regarding the equivalence between the process and regress. A hammer pushing down a nail and a nail pushing up a hammer both involve pushing as a source of change. Equivalent, sort of. An explosion and an implosion. Are they equivalent in any sense of the term? Cream dispersing into coffee and cream and coffee separating from each other: are they equivalent too? Perhaps if one postulates that there is nothing to processes but the interaction of forces and that process/regress forces are equivalent?]
The real problem is that the design stance and intentional stance, as described by DD, involve a kind of cheating that allows DD to import "something more" without clearly clarifying whether this "more" is subjective or objective. I think that if one asked that question and pursued both possibilities, then one might be able to come up with a destructive dilemma.
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