UPDATED: To keep commenters from going down blind bypaths due to my imprecision. Bear with me: I am just a jumped-up monkey, after all...
Thomas Nagel argued that his reason could not have been the result of blind Darwinian evolution. He said:
- My reason tells me that if the sun is rising on my right then I am going north then.
- I believe I am going south.
- I believe I see the sun rising on my right
- My reason tells me that I must reject one of these two beliefs because they are inconsistent--either I must conclude that I am hallucinating, or I must conclude that I am not going south.
- Et cetera…
- This kind of transcendent access to truths of objective reality is not something that a jumped-up monkey with Darwinian heuristics can have.
- Therefore I am more than a jumped-up monkey with Darwinian heuristics: I am angelic reasoning being with direct unmediated access to objective reality.
I responded that he knew nothing of the kind:
His Darwinian heuristics had made a Humean guess that because the sun had risen on his right if he was facing north every single previous day, that the same held true today. I pointed out that this might be wrong--that he did not know that because the sun was rising on his right he was facing north, and did not know that he knew that he was facing north, and did not know that he knew that he knew he was facing north, but that he was just guessing.
And, to underscore this, I pointed out that I had once seen the sun rise due south, in which case if I had put the sun on my right I would have been facing not north but east. (I did not point out--but could have--that the claim that if you are facing north east is on your right fails at the South Pole: at the South Pole east is not on your right, north is on your right.)
This seemed to me to be conclusive: what Thomas Nagel took as a canonical example of an angelic reasoning being with direct unmediated access to objective reality was, when examined, nothing of the kind--but rather merely another example of the sad delusions to which jumped-up monkeys operating on error-prone Darwinian heuristics are liable.
Now Gene Callahan enters the ring on the side of the angelic reasoning beings with direct unmediated access to objective reality. I don't think he does any better than Nagel.
Tell me what you think:
Gene Callahan:
La Bocca della Verità: Brad DeLong Jumps the Shark: You see, because he once reasoned wrongly about a situation he found himself in, that proves that Thomas Nagel is dumb! When you find yourself calling one of the greatest philosophers of the last half century dumb, something has gone wrong. And in this case, the problem is that Nagel has trampled upon DeLong's religious faith, which is materialism. This is naturally a shaky faith, since there is not a single shred of evidence in favor of its truth. So when a prominent, non-religious philosopher like Nagel notes that besides lacking any evidence in its favor it seems very implausible, there is nothing for it but to declare him stupid, so he can be safely ignored and the faith can be protected.
Brad DeLong: Well, your reason and Thomas Nagel's reason may provide you and him with transcendent access to objective reality, so that--as he says in his book--when he sees the sun rising on his right he knows immediately by the metaphysical necessity of the case that he is not going south but north. My reason does not: my reason is a set of heuristic guesses made by a jumped-up monkey with a set of brain circuits designed to detect whether the fruit is ripe or it is safe to jump to the next branch. And I hold with Hume that just because the sun usually rises in the east does not mean that it will always rise in the east. And, indeed, as I explained there was one morning when I saw the sun rise due south.
I don't believe your or Thomas Nagel's reason provides either of you with transcendent access to objective reality. And I think your strange delusion that it does simply reinforces my point that jumped-up monkeys like you and me do not have magic brains that give us transcendent access to objective reality.
:-)
Gene Callahan:
But Brad, if I follow your logic, than the idea that Nagel and I (and you) are just making heuristic guesses is itself just a guess on your part! If so, on what basis could you possibly advance for preferring your notion to ours, other than that, well, you prefer it? Why should you believe we are "jumped up monkeys"? After all, the theory of evolution is just a guess! It has "worked" in the past?! What, you think you have some direct access to reality to tell that it worked? That is just a guess on your part as well.
Or look at it this way, Brad: if you really thought that all knowledge claims, were just "heuristic guesses made by a jumped-up monkey" then you ought to be very humble about Nagel's claims: I would think you would say, "Well, Nagel's guess is different than mine, but what do I really know?" But nope: you are damned certain Nagel is wrong. What an extraordinary position for a jumped up monkey to be taking!
Brad DeLong: No, I shouldn't be humble. Nagel says that my reason could not have evolved because my reason has transcendent access to objective reality--and one thing that my reason has transcendent access to is that my reason has transcendent access to objective reality. But I don't believe that my reason has transcendent access to objective reality. In that case either (a) I am wrong, and my reason is wrong in thinking it does not have TATOR, in which case my reason clearly does not have TATOR--but Nagel claims that his reason does. (i) He might be mistaken... (ii) Alternatively, I am a being of different order than he is--an ape while he is an angel. That is possible... On the other fork, (b) I am right in my belief that my and his reason does not have TATOR--and Nagel's belief that he does is just another sad delusion of a jumped-up monkey.
Nagel's root problem is that he has to convince me that my reason knows things and knows that it knows things that my reason tells me that it does not know. An argument that depends on convincing me that I know things and know that I know things that I believe I do not know has a very high hill to climb...
Gene Callahan
"In that case either (a) I am wrong, and my reason is wrong in thinking it does not have TATOR, in which case my reason clearly does not have TATOR--but Nagel claims that his reason does." "Has access to" != "had accessed." The logic of the sentence above is about equivalent to "Nagel says I am capable of learning arithmetic. But I have not learned arithmetic. Therefore, Nagel is wrong!" You are aware that philosophical rationalists have offered some explanations as to why, despite having access to the world of forms, some people remain staring at the shadows on the cave walls?
Brad DeLong: Nagel chose the example. Nagel made the claim that it is his reason's transcendent direct access to objective reality that tells him: (a) the sun rises in the east, (b) if east is on my right I am facing north, and thus (c) when I see the sun rising on my right I know that I am facing north, and know that I know, and know that I know that I know.
I, by contrast, point out that that example is not an example of transcendent reason grasping objective reality, but of a Humean guess that might be wrong--and was in fact wrong.
I understand that you wish that Nagel had picked another, less silly example of reason's transcendent access to objective reality. But that was the example that he picked. And that he picked that example is evidence of the--extremely weak--strength of his case...
I do wonder: Does Gene Callahan have any idea what he has committed himself to when he endorses Thomas Nagel's claim that Nagel has transcendent direct access to truths of objective reality? I think not:
Thomas Nagel: Does Gene Callahan have any idea what he is committing himself to in endorsing Thomas Nagel's claim to have transcendent access to objective reality? I think not:
I decide, when the sun rises on my right, that I must be driving north instead of south... because I recognize that my belief that I am driving south is inconsistent with that observation, together with what I know about the direction of rotation of the earth. I abandon the belief because I recognize that it could not be true.... I oppose the abolition of the inheritance tax... because I recognize that the design of property rights should be sensitive not only to autonomy but also to fairness...
Game, set, match, and tournament!
Someone who claims to be a "friend" makes me aware that others are joining Alvin Plantzinga and Gene Callahan on the side of Thomas Nagel's creationists--those claiming that we reason and we know we reason like winged angelic reasoning beings with transcendent access to objective reality, rather than like jumped-up monkeys using error-prone Humean heuristics on brains evolved to improve our reproductive fitness, and hence we know that Darwin is wrong on the evolution of the human mind.
Steven Landsburg.
Steven Landsburg: Unreasonable: Brad DeLong appears to argue here that because pure reason once led him, Brad Delong, to an incorrect conclusion about which direction he was facing, it follows that pure reason can never be a source of knowledge. (If that’s not his point, then the only alternative reading I can find is that Thomas Nagel is guilty of choosing a poor example to illustrate a point that DeLong would rather ridicule than refute.) It would be too too easy to make a snarky comment about how we’ve known all along about Brad DeLong’s tenuous relationship with reason….
[H]ere, for the record… facts… none of them, as far as I can see, accessible to humans via anything but pure reason:
- The ratio of the circumference of a (euclidean) circle to its radius is greater than 6.28 but less than 6.29…
Has anybody ever seen a more complete case of self-pwnage?
STEVEN LANDSBURG: The ratio π of the circumference of a circle to its radius is such that 6.29 > 2π > 6.28
KARL SCHWARTZCHILD: That's odd. I have been studying this neutron star. The ratio of its circumference to its radius is definitely not your 2π.
STEVEN LANDSBURG: That's because it is not a Euclidean circle!
KARL SCHWARTZCHILD: And how do you know it's not a Euclidean circle?
STEVEN LANDSBURG: Because if it were a Euclidean circle, the ratio of its circumference to its diameter would be π!
KARL SCHWARTZCHILD: And so your demonstration that Darwin is wrong on the evolution of the human mind is simply that you can make "no true Scotsman!" arguments?
I must say, if Steven Landsburg had set out to strengthen my confidence that we reason like jumped-up monkeys using error-prone Humean heuristics on brains evolved to improve our reproductive fitness, he could not have done better than to write his post.
UPDATE: Gene Callahan, too, is not satisfied and returns for more:
Trying to Clear Up DeLong's Muddle for Him: First, let us look carefully at Nagel's example, and see what he is using it to demonstrate….
[S]uppose I observe a contradiction among my beliefs and “see” that I must give up at least one of them. (I am driving south in the early morning, and the sun rises on my right.) In that case, I see that the contradictory beliefs cannot all be true, and I see it simply because it is the case. I grasp it directly.... [W]hen we reason, we are like a mechanism that can see that the algorithm it follows is truth-preserving.... Something has... gotten our minds into immediate conact with the rational order of the world.... Rational creatures can... make up their own minds.... It does seem to be something that cannot be given a purely physical analysis and therefore... cannot be given a purely physical explanation. If I decide, when the sun rises on the right, that I must [not] be driving... south.... I abandon the belief because I recognize that it couldn't be true.... I operate in the space of reasons..."
So Nagel gives us two beliefs: 1) The sun rises in the east (where I am); and 2) I am driving south, which means the east will be on my left. And a fact: But the sun is rising to my right! So Nagel's point is that we cannot continue to hold 1) and 2) simultaneously: "I must give up at least one of them." How could he have said that more plainly?… Now, Brad Delong comes along and says, "What an idiot! [And he really does insult Nagel like that.] Once, I was in that situation, and I had to give up belief 1)!" Ahem. One does not disprove the proposition that one ought to give up at least one of two contradictory beliefs by showing how once, one gave up one of two contradictory beliefs. What DeLong ought to have done is, given that he had made the "heuristic guess" that he had just found one of the great philosophers of our time committing an elementary logical blunder, stopped and said, "Perhaps this here jumped up monkey needs to guess again?" Instead, he took his misreading and ran with it, and now insists on digging deeper and deeper into the mud of heuristic error.
Alas for Callahan, he gets it wrong again.
Nagel does not believe: "the sun rises in the east (where I am)." Nagel believes: "the sun rises on my right".
Thus the two beliefs that Nagel's reason tells him are in conflict are (a) his belief that he is going south, and (b) his belief he sees the sun rising on his right. The choice he gives himself is between concluding that he is going north and concludeingthat he is hallucinating.
Now I understand that Callahan wishes that Nagel were not Nagel but rather some Nagel' who had added a third belief: (c) "I am in a normal place (but there are weird places on earth where the sun rises in a non-standard way)."
But we go to argument with the Nagel we have, and not the Nagel' Callahan wishes we had.
Callahan would presumably say that Nagel was just being sloppy, and that there is actually an unsloppy Nagel' who had made the argument that Callahan wishes he had made, and whose reason does have transcendental access to objective reality, and that we should deal with the argument not of Nagel but of Nagel'.
But Callahan's confusion of the Nagel' he wishes we were talking about with the Nagel who we are talking about demonstrates my big point quite effectively: powerful evidence that Nagel is a jumped-up monkey using wetware evolved to advance his reproductive fitness, rather than a winged angelic reasoning being with transcendental access to objective reality. No?
David Hume vs. Thomas Nagel: Knowing a Hawk from a Handsaw But Mad South-Southwest Weblogging
Tyler Cowen writes:
The new Thomas Nagel book: The title is Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False…. My bottom lines on it: (1) He is good on attacking the hidden hypocrisies…. He fully recognizes the absurdities (my word, not his) of dualism, and thinks them through carefully and honestly. Bryan Caplan should beware…. The most typical sentence I found in the book was: “We can continue to hope for a transcendent self-understanding that is neither theistic nor reductionist.”… He doesn’t take seriously enough the view: “The Nagel theory of mind is simply wrong.” People will dismiss his arguments to remain in their comfort zone, while temporarily forgetting he is smarter than they are and furthermore that many of their views do not make sense or cohere internally…
And here Tyler appears to me to have gone off the rails. Thomas Nagel is not smarter than we are--in fact, he seems to me to be distinctly dumber than anybody who is running even an eight-bit virtual David Hume on his wetware.
Nagel's argument, to the extent that I understand it and that it is coherent, goes roughly like this:
Suppose we think we are going south-southwest and see the sun rising before us. We don't think: "the heuristics of reasoning that have evolved because they tend to boost reproductive fitness conclude that it is very likely that I am not in fact going south-southwest". We think, instead: "I know that the sun rises in front of me when I am going east! Either I am hallucinating, or I must be going roughly east! I deduce this by my reason, and my reason is a mechanism that can see that the algorithm it follows is truth-preserving! My mind is in immediate contact with the rational order of the universe! I don't just think I am going east! I know I am either hallucinating or going east! And my certainty that I know must be correct! And I know that my certainty must be correct--and that triumph of reason cannot be given a purely physical explanation! Since I believe I am not hallucinating, I abandon the belief that I am going south-southwest because of my reason's transcendent grasp of objective reality! My consciousness is an instrument of transcendence that grasps objective reality! And no blind evolutionary process can produce such a transcendent instrument!"
The problem is that it happened to me.
I thought I was going south-southwest, saw the sun rising at 11 o'clock by the compass, believed that I was in fact going east--and I was wrong: I was in fact going south-southwest.
Thomas Nagel: Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Surely False:
Evolutionary naturalism provides an account of our capacities that undermines their reliability, and in doing so undermines itself…. The application of evolutionary theory to the understanding of our own cognitive capacities should undermine… them…. [T]he evolutionary hypothesis would illy that though our cognitive capacities could be reliable, we do not have the kind of reason to rely on them that we ordinarily take ourselves to have…. Evolutionary naturalism implies we shouldn't take any of our convictions seriously, including the scientific world picture on which evolutionary naturalism itself depends….
Our own existence presents us with the fact that somehow the world generates conscious beings capable of recognizing reasons… distinguishing some necessary truths…. [W]e find it undeniable, as we should, that our clearest moral and logical reasonings are objectively valid….
[…]
[I]n a case of reasoning, if it is basic enough, the only thing to think is that I have grasped the truth directly. It is not possible to think: "Reliance on my reason, including my reliance on this very judgment, is reasonable because it is consistent with its having an evolutionary explanation." Therefore any evolutionary account of the place of reason presupposes reason's validity and cannot confirm it without circularity…. Reason can take us beyond appearances because it has completely general validity….
[...]
The existence of conscious minds and their access to the evident truths of ethics and mathematics are among the data that a theory of the world and our place in it has yet to explain. They are clearly part of what is the case….
[...]
The distinctive thing about reason is that it connects us with the truth directly.... [S]uppose I observe a contradiction among my beliefs and “see” that I must give up at least one of them. (I am driving south in the early morning, and the sun rises on my right.) In that case, I see that the contradictory beliefs [(a) that I am going south, and (b) that the sun is rising on my right] cannot all be true, and I see it simply because it is the case. I grasp it directly.... [W]hen we reason, we are like a mechanism that can see that the algorithm it follows is truth-preserving.... Something has... gotten our minds into immediate conact with the rational order of the world.... Rational creatures can... make up their own minds.... It does seem to be something that cannot be given a purely physical analysis and therefore... cannot be given a purely physical explanation.
If I decide, when the sun rises on the right, that I must [not] be driving... south.... I abandon the belief because I recognize that it couldn't be true [and because I reject the possibility that I am hallucinating].... I operate in the space of reasons...
[...]
[A] theory of everything has to explain.... the development of consciousness into an instrument of transcendence that can grasp objective reality and objective value…. In light of the remarkable character of reason, it is hard to imagine what a naturalistic explanation of it, either constitutive or historical, could be like...
I was sitting in a port-side window seat of an airplane, headed for San Francisco from London. I woke up and looked at the position-plot screen on the back of the seat in front of me: we were headed south-southwest, on the last leg of our journey. Then I looked out the window and I saw the sun rise at 11 o'clock by the compass. "That is due south", I thought. "The sun does not rise due south. Something must be wrong with the plane's navigational system!"
At that moment I felt with Thomas Nagel describes as the triumph of reason: I knew with immediate absolute certainty that we must not be flying south-southwest but instead east, I was in immediate contact with the rational order of the universe, my consciousness was an instrument of transcendence that grasped objective reality, and that objective reality was that we were flying east toward the rising sun.
Of course we were not.
Of course I was wrong.
During northern hemisphere winter, if you are near the North Pole, it is perfectly possible to see the sun rise due south if you are due solar north of the center of the earth as you come out of the Earth's shadow. And I was. And I did.
Thus Thomas Nagel's insistence that we need a theory of consciousness that accounts for our reason's ability to become an instrument of transcendence that grasps objective reality--that insistence falls apart like an undercooked blancmange, because the only concrete example I remember from the book of "transcendent reason grasping objective reality" is nothing of the kind. Any theory that provided such an account of reason becoming an instrument of transcendence and offering guarantees of grasping objective reality would be hopelessly, terribly, laughably wrong. I agree that our heuristic reasoning is remarkably good for jumped-up monkeys. But it can and does go terribly, hopelessly, laughably wrong--no more so than when it tries to generate guarantees of its own papal infallibility out of thin air.
And I cannot help but think that only a philosophy professor would believe that our reason gives us direct access to reality. Physicists who encounter quantum mechanics think very differently...
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