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Tuesday, November 27, 2012

Trying to Clear Up DeLong's Muddle for Him

Previous post, should you want the background here.

First, let us look carefully at Nagel's example, and see what he is using it to demonstrate (emphasis mine):

"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 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?

Then Nagel goes on to state that "IF" (notice, that "if" is right in the original text, I did not add it!) he decides to give up belief 2), it will be because he sees he cannot logically hold 1) and 2) at the same time. Notice what the "if" implies: Nagel clearly understands that he has the option of giving up belief 1) instead! Otherwise, no point to the "if."

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.

Game over.

25 comments:

  1. I understand your reading of Nagel to be the following: Nagel argues that he possesses an ability, Reason, which allows him to recognise truth directly - in this case, the truth he recognises ("grasps directly") is that two contradictory things cannot be true at the same time.
    Further, this ability to recognise a logical truth puts him in contact with "the rational order of the world".

    I think the materialist counter-argument is that in recognising this truth what Nagel is doing is slightly re-purposing mental circuits that evolved to make logical deductions about the world (I thought that there was one lion in the cave, I just saw two lions come out, I now know I must be cautious since I was wrong about my first belief). This type of reasoning is commonly observed in animal experiments.

    This reasoning has well defined failure modes (like our lack of understanding of probability, or the difficulty we have in reasoning about the properties of aggregates vs individual parts) that are consistent with the idea that our thinking is an extension of heuristics built around spatial and visual metaphors that evolved to help us survive, more than some privileged access to a world of pure reason.

    More, our ability to press these mental models to alternative service has been greatly stretched by such things as quantum mechanics, where our intuition fails utterly. Our ability to progress here depends on slowly building tools (mathematics) over a long time to help compensate for the deficiencies in our raw thinking ability. This tool building is an essentially social enterprise much bigger than a single human brain.

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    1. I know, Peter, materialists say the silliest things, don't they? But let's go easy on them, ok?

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    2. Wait, what? You're just going to dismiss that point with condescension instead of substance?

      What about superposition? Even if we accept your charitable reading of Nagel, his claim that we have to reject two contradictory viewpoints doesn't hold true in a world where we can have a Schrodinger's Cat.

      How can this be reconciled? If even logical contradiction fails to universalize, what aspect of our reason is objective and transcends heuristic reasoning?

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    3. Yes, I am. Because it is silly. Superposition is not a logical contradiction! And a world with Schrodinger's Cat does not entail two contradictory viewpoints being true. It just shows the physical world is stranger than we imagined. The fact that we figured this out was a triumph of reason, every step along the way. If the developers of the theory were not adverse to holding contradictory views, then why would they have had any troubles about facts which contradicted Newtonian physics! They would have just shrugged and said "So what? A contradiction: big deal."

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    4. How is it not a logical contradiction? It violates the law of excluded middle. The Cat is both alive and not alive. Clear violation of Russell's 3rd axiom.

      And the thing is, we haven't "figured this out" That is why Einstein rejected quantum physics via the EPR paradox, Why Schrodinger wrote about the cat, and why Feynmann famously said "I think I can safely say that nobody understands quantum mechanics." We can follow rules to manipulate symbols and create QM predictions, but its implications are deeply inimical to our ways of thinking.

      As an analogy, even if I understand how an optical illusion works, that doesn't mean I choose not to see it. And even if I can write an equation to model the wave function of Schodinger's Cat, it doesn't mean that I can conceive of how a cat is simultaneously alive and dead.

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    5. "The Cat is both alive and not alive."

      Wrong. The cat -- and of course, we don't know this actually applies to macro objects at all -- is NOT "both alive and not alive." Look here: not a single one of the interpretations involves any logical contradiction.

      'And the thing is, we haven't "figured this out"'

      Riiiiight. Space aliens developed quantum physics, and we just read their teextbooks.

      "That is why Einstein rejected quantum physics via the EPR paradox..."

      Wrong. Einstein didn't like the idea of instantaneous action at a distance. But there is nothing "illogical" about it, and it presents no "paradox."

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  2. One more time...

    Re: "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?…"

    But you will note that Nagel does not say "the sun rises in the east (where I am)." Nagel says: "the sun rises on my right". The choice his reason gives him is between giving up either the belief that he is going south--i.e., he can conclude he is going north instead--or giving up the belief he sees the sun rising on his right--i.e., he can conclude that he is hallucinating.

    Once again, Nagel does not say what you wish he had said. You can say that he is just being sloppy, and that there is actually an unsloppy Nagel' who makes the argument that you wish he had made and whose reason does have transcendental access to objective reality.

    But your resort to Nagel' demonstrates my point, no?

    Brad DeLong

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    1. OK, Brad, I think he is saying exactly what I "wish" he had said, and that you are misreading him. So did about half a dozen other commenters at your own blog. But we at least now each understand what the other one reads Nagel as saying. Other than one of us pulling Nagel out from behind a column a la Woody Allen with Marshall McCluhan in Annie Hall, we are both likely to stick to our readings.

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    2. "or giving up the belief he sees the sun rising on his right--i.e., he can conclude that he is hallucinating."

      And note well: Brad just made this part up and stuck it in Nagel's mouth to make him look dumb. This is not anywhere in the original text!

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  3. "The distinctive thing about reason is that it connects us with the truth directly....In that case, I see that the contradictory beliefs cannot all be true".

    Are you saying that we have direct access via reason to the truth or untruth of the Bible, for instance? If so, what is the answer? Is it true or untrue?

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    1. What the hell?!

      "In that case, I see that the contradictory beliefs cannot all be true."

      (And this was Nagel, by the way, not me.)

      "I" am (Nagel is) saying contradictory beliefs cannot all be true.

      Somehow, out of that, you get "that we have direct access via reason to the truth or untruth of the Bible"?! How in the world did you move from Nagel's statement to that.

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    2. My bad, I thought it was common knowledge that the Bible has quite a few contradictions; and so was curious how people endowed with reason that connects them to the truth directly and that naturally see that contradictory beliefs cannot all be true reconcile their Christian beliefs.

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    3. "I thought it was common knowledge that the Bible has quite a few contradictions..."

      I agree, it does!

      "reconcile their Christian beliefs."

      Because a Christian need not believe the Bible is inerrant?

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    4. And yes, some Christians DO believe that, no doubt. But others think that when divine revelation is piped through flawed human beings, those humans sometimes muddle it up a bit!

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    5. And Arun, I don't mind talking with you, but you are new here, and I have little patience for those who will waste my time. I have a lot of commenters who challenge me all the time, but they at least deal with my response to their argument one before they post argument two. When someone just ignores how I've dealt with their first argument and simply goes on to post another objection, I suspect trolling. And trolls are unwelcome!

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    6. You had to make three replies to my one question? Seems to me it was a legitimate challenge not a troll.

      Anyway, you replied in another thread to my post about there not being any equivalence classes for algorithms, without including my post. If there are no equivalence classes for algorithms, then there is no mathematical property and no physical property which makes them the "same". The paper I cited - a serious scientific paper - of course, makes the arguments but does not prove the point, but it needs to be engaged with if you want to make your point.


      I pointed to the Platonic world of ideals idea, asking if that was your argument, that the Platonic world is real. If it is, then I intended to point out that you'd have support for that idea from scientists like Roger Penrose. But you didn't bother to publish that comment either.

      If the conversation continued, I might have pointed out some Vedantic ideas as well, which can be adapted to argue that consciousness is an irreducible primary component of the universe. If you don't want to go that route, there is stuff in Douglas Hofstadler that can be used to make a similar argument.

      It seems to me that you are close-minded, and your "Mouth of Truth" is some grandiose self-deception, you're more interested in staying where you are rather than moving forward and this is a place that would waste my time as well.

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    7. 'Anyway, you replied in another thread to my post about there not being any equivalence classes for algorithms, without including my post. If there are no equivalence classes for algorithms, then there is no mathematical property and no physical property which makes them the "same"'

      Yes, this makes my point nicely: it is the *idea* of the sieve of Eratosthenes that makes all implementations of it "the same." (And I was a software engineer for 20 years, and believe me, anyone who could not grasp the notion of "the same" algorithm running on different computers or in different languages would have been totally useless as a programmer!)

      "It seems to me that you are close-minded..."

      It seems to me you rush to judgment of others.

      And "Mouth of Truth" is a joke, OK? You didn't notice the ridiculous image?

      What I am is busy. Therefore, I try to sort out trolls from decent conversational swiftly. I have heuristics for doing this that work very well for a jumped-up monkey, thank you.

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    8. "decent conversationalists"

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  4. I feel like I am missing something here. I do not understand how accepting that "contradictory beliefs cannot all be true" must necessarily lead us to the conclusion that "Rational creatures ... [making] up their own minds ... cannot be given a purely physical analysis."

    Of course, Mr Nagel's actual assertion is closer to:
    The fact that "contradictory beliefs cannot all be true" seems to lead us to the conclusion that "Rational creatures ... [making] up their own minds ... cannot be given a purely physical analysis". (“Seems to lead” is a long way off from “Must necessarily lead”)

    I will accept Mr. Nagel's word that this is how the matter seems to him. It seems to me that we don't understand nearly enough about our brains and our senses (and what our brains do with their sensory input) to know that physical processes alone cannot create a reasoning intellect.

    Perhaps I am missing something here, and I should simply accept Mr. Nagel's "seems".

    On the other hand, there are many physical phenomena that seem to be true yet are, in fact, false. (For example, it *seems* that my chair is not moving, yet it, I, the desk, and my computer are all travelling at a speed of some 770+ miles per hour along with the rest of the spinning Earth here at Boston’s latitude).

    I read DeLong as claiming that a purely physical explanation of intellect might very well be sufficient to explain the observation that, when faced with contradictory beliefs:
    1) Sometimes we can use reason to identify which belief is true, and
    2) Other times both beliefs were true all along and we were wrong in believing them to be contradictory.

    Perhaps Mr. Callahan can explain precisely how Nagel's argument shows that that a purely physical system cannot display both 1) and 2) -- I can't see the connection myself.

    Best,
    Jim Bales

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    1. "I feel like I am missing something here. I do not understand how accepting that "contradictory beliefs cannot all be true" must necessarily lead us to the conclusion that "Rational creatures ... [making] up their own minds ... cannot be given a purely physical analysis."

      I did not make or defend that argument, ever. (I'm not saying it's wrong, but I haven't even read Nagel's book, and I would want to see his whole argument before I even spoke about it.

      What *I* said was that DeLong completely misunderstood Nagel's point in the passage he quoted. Which is true, as I have shown. Don't ask me to defend claims someone else made and upon which I have never commented.

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  5. Mr. Callahan writes:
    What *I* said was that DeLong completely misunderstood Nagel's point in the passage he quoted. Which is true, as I have shown.

    I am not convinced that DeLong misunderstood Nagel's passage.

    I read DeLong as understanding that Nagel is claiming that "contradictory beliefs cannot all be true".

    With that understanding, DeLong goes on (as I read him) to refute that claim by giving a counter-example -- one from DeLong's own experience.

    The counter-example is a circumstance in which a person held two contradictory beliefs that were, in fact, both true, and it was that person's belief in the contradiction that was false.

    Granted, DeLong was neither polite nor kind in presenting his counter-example. However, the counter-example does appear to be tailored to refute Nagel's claim that "contradictory beliefs cannot all be true" by noting that our belief in the contradiction is also suspect.

    So, I don't see how DeLong misread Nagel. But, perhaps I am missing something.

    best
    Jim Bales

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    1. Come on, Jim, be for real here: "two contrary beliefs cannot both be true" is not contradicted by "Sometimes beliefs we think are contrary are not really contrary"!

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    2. Or look at it this way, Jim: while I don't think DeLong read Nagel correctly, even if he had, what he ought to have written was "Nagel is, of course, correct in in his primary contention that two contradictory beliefs cannot both be true. Unfortunately, he chose a bad example to illustrate this true point."

      Instead, what he wrote was basically: "Nagel: idiot."

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    3. Consider the statement:
      "Sometimes beliefs we think are contrary are not really contrary"

      There are three elements embedded in this statement. Two of them are labeled as beliefs (call them Belief A and Belief B). Then there is a third element ("Beliefs A and B are in contradiction") that is labeled as a thought.

      Why is the third element a thought and not a belief?

      Nagel's argument hinges on the assertion that we "see [the contradiction] simply because it is the case." DeLong's counter-example shows that we cannot distinguish between contradictions that we see "simply because it is the case" and the false contradictions that we *think* we see but are not really contradictions.

      Without the ability to "see [a contradiction] simply because it is the case", Nagel's argument fails.

      If we had a truth-o-meter, we could use it to determine which of our perceived contradictions are true and which are false. Nagel claims that we have a truth-o-meter that tells us when we have conflicting beliefs. DeLong points out that Nagel's "truth-o-meter" is indistinguishable from a heuristic.

      In other words:
      "Absent a truth-o-meter, there are times when two contradictory beliefs are, in fact, true, and it is the belief that they contradict that is false. Mr. Nagel does not make a convincing case that a truth-o-meter exists."

      Best
      Jim Bales

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    4. Me: People have the capability of walking.
      JIm: I once saw a baby fall down! Your argument fails!

      Me: People have the capability of doing arithmetic.
      Jim: Ha, I once made a mistake in adding up a column of numbers. Your argument fails!

      If Nagel, or any rationalist anywhere ever, had said, "Our reason has INFALLIBLE access to reality," you certainly would have crushed their case.

      But since neither Nagel nor any rationalist anywhere at anytime has ever said that, I'm starting to think you are wasting my time.

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