Your Weekend Reading

Let me wrap up the week’s blogging by directing you to two essays related to things we’ve been discussing this week.

The first is Mohan Matthen’s review of Thomas Nagel’s book in The Philosopher’s Magazine. I refer you to it partly because it’s an interesting essay in its own right, but also because he seizes on precisely the Nagel quote that caught my attention in this post. Matthen writes:

This is perhaps the moment to come back to the strange pronouncement to which I earlier alluded. Nagel writes, “With regard to evolution, the process of natural selection cannot account for the actual history without an adequate supply of viable mutations, and I believe it remains an open question whether this could have been provided in geological time merely as a result of chemical accident, without the operation of some other factors determining and restricting the forms of genetic variation. It is no longer legitimate simply to imagine a sequence of gradually evolving phenotypes, as if their appearance through mutations in the DNA were unproblematic – as Richard Dawkins does for the evolution of the eye.” (Versions of this claim are repeated at many points in the book.)

Now, this is a scientific challenge to the viability of Darwinian explanation, not just a reflection on its explanatory completeness. The sufficiency of genetic variation to drive natural selection has been a central theme since R A Fisher’s great book, The Genetical Theory of Natural Selection. Nagel, a philosopher, tells us there’s not enough. Big result! But it’s completely unsupported by argument. Nagel says that he would “like to defend the untutored reaction of incredulity to neo-Darwinism … It is prima facie highly implausible that life as we know it is the result of a sequence of physical accidents together with the mechanism of natural selection”. This is just irresponsible. It is simply wrong to adjudicate the probability of mutations by an “untutored reaction of incredulity”. Probability assessments notoriously run counter to common sense. If you think you have a scientifically viable argument, give it, or leave it to scientists to deal with this kind of problem!

That’s pretty close to what I said!

Also interesting is this article by Stephen Cave over at e-Skeptic. He is addressing the question of the soul:

The evidence of science, when brought together with an ancient argument, provides a very powerful case against the existence of a soul that can carry forward your essence once your body fails. The case runs like this: with modern brain-imaging technology, we can now see how specific, localized brain injuries damage or even destroy aspects of a person’s mental life. These are the sorts of dysfunctions that Oliver Sacks brought to the world in his book The Man Who Mistook His Wife For A Hat.4 The man of the title story was a lucid, intelligent music teacher, who had lost the ability to recognize faces and other familiar objects due to damage to his visual cortex.

Since then, countless examples of such dysfunction have been documented—to the point that every part of the mind can now be seen to fail when some part of the brain fails. The neuroscientist Antonio Damasio has studied many such cases.5 He records a stroke victim, for example, who had lost any capacity for emotion; patients who lost all creativity following brain surgery; and others who lost the ability to make decisions. One man with a brain tumor lost what we might call his moral character, becoming irresponsible and disregarding of social norms. I saw something similar in my own father, who also had a brain tumor: it caused profound changes in his personality and capacities before it eventually killed him.

The crux of the challenge then is this: those who believe they have a soul that survives bodily death typically believe that this soul will enable them, like Nathalie in the story above, to see, think, feel, love, reason and do many other things fitting for a happy afterlife. But if we each have a soul that enables us to see, think and feel after the total destruction of the body, why, in the cases of dysfunction documented by neuroscientists, do these souls not enable us to see, think and feel when only a small portion of the brain is destroyed?

That looks like a good argument to me. What do you think? There’s more to Cave’s article than what I’ve quoted, so go read the whole thing!


  1. #1 Sascha Vongehr
    March 30, 2013

    You keep bashing Nagel getting the science wrong; the “philosophers” defend him via the usual claim in that case, namely that it is all meant on a more profound level; that the philosophy is all marvelous. But he fails precisely because he gets the philosophy wrong:

  2. #2 MNb
    March 30, 2013

    Sorry, I won’t have time this weekend for this subject. You know, Carlsen lost and Kramnik took over the lead! That’s far more interesting than the subject of the human soul, which is pretty settled afaIc.
    (note for those who think otherwise: 30 years ago I was a dualist)

  3. #3 Jason Rosenhouse
    March 30, 2013

    MNb —

    I know what you mean! This is turning out to be one of the most exciting chess tournaments I can remember. I was gearing up to right the “Magnus Carlsen Fulfills His Destiny” post, and now it looks like we might have a Kramnik — Anand rematch instead. There are still two more rounds, though.

    For those who don’t know what we’re talking about, click here.

  4. #4 Swimmy
    March 31, 2013

    The latter is an incomplete argument. The dualists will always and forever have a logical response to any such complaints: They maintain that the brain is a tool the mind uses. If it gets broken, the mind can’t use it, but the mind is still intact.

    The example I saw that made sense to me: imagine a person in a box who uses a radio to communicate with the outside world. The radio ceases working and the person can no longer communicate. It’s illogical to conclude that the person inside is dead.

    Now, since whether a person is in the box is exactly what’s in question, and since brains are far more complicated than radios, the conjunction rule and Occam’s razor weigh against dualism unless there’s further evidence. That evidence could be: 1) Similar to Nagel’s tack, demonstrations that the brain isn’t enough to be a human, just like a radio isn’t enough to be a human. And no, prima facie intuitions are not sufficient. Instead, a proof that minds defy some known physical laws would settle it rather nicely–for instance, demonstrable changes in mind states without corresponding changes in brain states–though our technology couldn’t settle that yet. 2) Related, the man could jump out of the box and prove his existence by doing things he could never do inside, and that his radio certainly couldn’t do. I eagerly await dualist defenses of telekinesis and ESP.

    Any other ideas about what evidence would overcome the improbability? Surely I’m missing several things.

  5. #5 Jason Rosenhouse
    March 31, 2013

    Swimmy —

    Cave addresses your counterargument in his article.

  6. #6 bad Jim
    March 31, 2013

    I can’t understand why Nagel thinks that the theory of evolution is deficient because it can’t explain why consciousness must exist, when it’s practically axiomatic that evolution is a process of accidents, each contingent on the last. It’s as though he presumes something like “specified complexity”, which though intuitively appealing to a certain audience is notoriously difficult to define.

  7. #7 couchloc
    March 31, 2013

    “The evidence of science, when brought together with an ancient argument, provides a very powerful case against the existence of a soul that can carry forward your essence once your body fails.”

    I’m not sure how these two readings are supposed to be related. If the second is supposed to be a response to Nagel somehow, I’m afraid I’m confused. Nagel does not believe in the existence of a soul that can survive the death of the body. So it’s just irrelevant to anything he has to say on the subject since he doesn’t believe in God or religion.

  8. #8 Jason Rosenhouse
    March 31, 2013

    couchloc —

    The two readings are not related to each other. I just thought both were interesting.

  9. #9 couchloc
    March 31, 2013

    Got it. Matthen is very good on biology and knows his stuff, so it’s disconcerting that he thinks Nagel has gotten this part of his account wrong (as Sober thinks too). My sense is that people think Nagel has made errors in some of his claims about evolutionary theory, but that his complaints about consciousness being irreducible to the brain are on firmer ground.

  10. #10 MNb
    March 31, 2013

    “Magnus Carlsen Fulfills His Destiny post”
    He does! If you have nerves like his, on that level, you are WCh material.

    “consciousness being irreducible to the brain are on firmer ground”
    Philosophy is not enough. Give me empirical data related to consciousness which cannot be described by scientific models. Otherwise the immaterial aspect of consciousness falls in the same category as Russell’s Teapot.

  11. #11 Juan Pineda
    March 31, 2013

    What is life? What is consciousness? These are the parts of the “cosmological software” that are more difficult to understand for us. The Mind of the Universe has created fascinating software. The process of reverse engineering that we call science is a magnificent tool to achieve understanding of this complex software. But we cannot replace the history as a source of knowledge with science, nor can we replace ethics as a source of knowledge with science. So there is more to knowledge than science; and that is not saying that science is not important. But it is from introspection, not from science, that we know what consciousness is. In regards to our knowledge of consciousness, science can complement the knowledge we obtain from introspection but it is introspection that provides the key for our understanding. What is the principle of live? We don’t know. What is the principle of consciousness? We don’t know. Can thoughts exist independently of atoms? We don’t know. Are brain waves thoughts? Can thoughts be measured? We don’t know. But thanks goodness we have introspection and by using it we all know quite well what thoughts are.

  12. #12 Swimmy
    April 1, 2013


    I don’t think the article quite captures the objection. The person-in-a-box analogy is better than the TV analogy, and the two are subtly different. For instance, Cave writes, “Most believers expect their soul to be able to carry forward their mental life with or without the body; this is like saying that the TV signal sometimes needs a TV set to transform it into the picture, but once the set is kaput, can make the picture all by itself.” The man-in-box analogy avoids this criticism. A person never only needs a radio to express her thoughts when she is trapped in a box. Once out, she is free to speak as she pleases.

    I will not at all contest that neuroscience doesn’t undermine either analogy. They are both harmed by evidence that the radio/tv can do whatever the dualist is claiming on its own, and the cog-psy literature is some of the strongest evidence against dualism.

  13. #13 Anonymous
    April 1, 2013

    I would really like to view more posts in this way!.. Great blog by the way! reis Fell..

  14. #14 Swimmy
    April 1, 2013

    Boy, reading that comment several hours later, there sure are a lot of errors an unclear sentences. I was trying to say that neuroscience definitely hurts the case for dualism. Derp.

  15. #15 MNb
    April 1, 2013

    Today must have been the craziest final round ever. How to qualify for a WCh match? By losing as White! And Kramnik made about the lousiest opening choice ever – the Pirc already is questionable on his level, but 6…a6 and 7…Nc6 followed by 10…e5 is far beyond my patzer comprehension.

  16. #16 Jason Rosenhouse
    April 1, 2013

    It was very annoying that I had to teach all morning, since that meant I mostly wasn’t able to watch the games live. Kramnik and Carlsen both losing in the last round was definitely not the outcome I expected. Kramnik has used the Pirc several times before. He probably felt he really needed to mix it up a bit to generate winning chances with black. Since Ivanchuk was mostly having a bad tournament, he probably figured he could outplay him.

    Meanwhile, Ivanchuk’s tournament was mostly a disaster, but he notched up wins against both Carlsen and Kramnik!

  17. #17 Anton Mates
    April 2, 2013


    For instance, Cave writes, “Most believers expect their soul to be able to carry forward their mental life with or without the body; this is like saying that the TV signal sometimes needs a TV set to transform it into the picture, but once the set is kaput, can make the picture all by itself.” The man-in-box analogy avoids this criticism.

    I think the box analogy also slightly misses Cave’s point, though. You’re using the radio’s audio output to represent the person’s attempts at external communication, or other interaction with the outside world. Messing with the radio might affect how the person’s voice comes through to the rest of us, but it shouldn’t radically alter the actual content of what the person is saying, let alone thinking. (Except if the person starts swearing because they notice that no one on the other end can understand them, I suppose.)

    Cave, on the other hand, is using the TV’s picture to represent the person’s mental state itself, or a vital component of that mental state. In that case, messing with the TV doesn’t just change what the person says or does, it changes how they feel and think. If the screen is blue for sadness or pink for joy, then you can actually affect the person’s subjectively experienced emotional state by turning the “tint” knob.

    It’s generally accepted that physical insults to the brain do in fact affect the introspected mind–e.g., if I take a hammer to the head or drink two bottles of vodka, I won’t just act weird or say weird things, I’ll feel weird and perhaps won’t feel anything at all for a while. So I think Cave’s analogy is pretty apt here.

  18. #18 Swimmy
    April 2, 2013

    Hmm. Point taken. I suppose you could stretch the analogy to allow the radio to be a complicated computer that could be manipulated to send messages the person in the box isn’t, but by that point we’re getting to pretty desperate territory. I retract my objection.

  19. #19 Anton Mates
    April 2, 2013

    Actually, stretching the analogy in that direction gets you to a Buddhist or Gnostic or New Age position, doesn’t it? Where even your thoughts and feelings, or some of them, are part of an “earthly self” you’d like to quiet down or peel away to reveal the real you. And if there’s basically nothing left to be the real you, well…that’s Nirvana maybe? Desperate territory, but not necessarily unpopular…

    Also, in fairness to the Abrahamic faiths, plenty of people believe in a mortal soul which, by itself, doesn’t think or feel. (In fact, I think this may be the mainstream belief in Islam.) They hold that God will make new, awesome bodies for the afterlife and plunk our souls in them and then we’ll really live again. Actually, even the Jews and Christians who believe in a conscious, disembodied soul state also mostly think that such a state will be temporary, and there will be a physical resurrection in the end. Their bodies will be glorified and immortal, but they’ll still be bodies.

    So Cave’s particular argument doesn’t really apply to a lot of afterlife conceptions, not that you can’t argue against them on other grounds.

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