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... I
