Monday, May 24, 2010

Level With Me

This post is part of my series on free will.


Let's return to the idea of levels of description. An action can be described on many different levels: the electron/molecular level, the neural level, and the mental level of thoughts and desires. Very possibly there are intermediate levels of description in terms of various brain subsystems, but I don't think those levels are currently well enough understood to be very useful.


At the level of electrons, atoms, and molecules, the description ought to be quantum mechanical, and thus indeterministic.


At the level of individual neurons, the description might be effectively deterministic, or it might not. It all depends on whether the neurons act as quantum amplifiers (like the Geiger-counter-bomb) or quantum dampers (like a computer). It seems conceivable to me (having very little knowledge of neuroscience) that at times, a single ion tunneling across the cell wall could be the difference between a neuron firing or not. This would make the neuron a quantum amplifier: the randomness of the tunneling event could get amplified and end up determining whether or not you perform some action. But maybe not - maybe the neuron is more like a computer transistor, which is designed so that a few electrons more or less don't make a difference to the outcome.


What about the level of mental events? Here the description is so loose, I would find it difficult to call it deterministic. Suppose I am considering which university to attend. I have reasons in favor or against both of my top choices: one is closer, the other gave me more aid, one is small and intimate, the other is large and has lots of opportunities.... But someone else with the same list of reasons could end up with the opposite decision, without being irrational about it. I suppose we could put weights on all the reasons and devise a formula that would determine the result - but how to decide on the weights and the formula? And would it work again if I had to make the decision again? So perhaps at this level Ekstrom's "caused but not determined" makes sense.


In my opinion, many of the difficulties involved with free will are the result of confusing different levels of description. Here is Ekstrom, for example (Free Will, pp. 195-196):


The idea that we can direct our behavior by our thoughts ... is welcome, but it is only superficially comforting. It comforts until we think about the possibility that even our thoughts are driven to be what they are by previous neurophysiological events (between which there are deterministic causal links), a chain going backward through events in our childhood brains and to events prior to our birth.

Notice how she slides from the mental level, to the neural level, to the micro-physical level of "events prior to our birth" without batting an eye. (Clearly there cannot be a neural level before there are neurons, so she must be thinking here of the electronic/atomic level.)

Sometimes the argument is phrased in terms of ultimate responsibility: You cannot have ultimate responsibility for something that you do not have control over. You do not have control over the events of the distant past that are the causes of your behavior today (if determinism is true). Therefore, you do not have ultimate responsibility for your actions.

But recall the Mars rover that had to turn left or right when confronted with a large rock. It would be very strange to say the computer program that made the rover turn left doesn't have responsibility for the decision to turn left because, at the electronic level, everything is determined by the laws of physics. That seems to get the causality exactly backwards. We would rather say that the computer program, together with the computer hardware, caused the electrons to flow in such a way as to make the rover turn left. So here is one case where the higher level is the cause of what's happening at the lower level, rather than the other way around. Or perhaps this is using "cause" in a different sense - another thing I find missing in the philosophers I've read is a careful analysis of causation.

To be continued....

3 comments:

  1. Call me a philistine but I think your last paragraph explains exactly why free will is a pseudoproblem. When we or a machine make decisions, the particles that make us up behave in ways which we have reason to describe as "making a decision". For instance, being part of a computational circuit whose causal structure makes the answer dependent on something that at the higher level can be described as a complex analysis of the situation.

    And yes, it is because the particles are arranged in a way that (at the higher level) can be seen a computation that the action (at the lower level) is controlled in such a fine way. If not, it would be a rock and not a circuit or brain. This is actually what Hofstadter argues in I Am A Strange Loop so this explanation in some good company.

    But with that, it seems this explains the entirety of a system. In which case the other aspects discussed by those embedded in the free will debate are phantoms.

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  2. Why would I call you a philistine when you're agreeing with me? ; )

    The more I think about it, the more convinced I am that Hofstadter, Dennett, and co. are right, and people like Ekstrom are indeed chasing phantoms.

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  3. I can't believe people are still having a hard time with this. Einstein had if figured out 100 years ago, and he explained it easily enough. It wasn't even his idea. Mammalian nervous systems are effective deterministic. They are robust to noise, in particular. Sure, technically the de Broglie hypothesis holds true- all matter has wave-like nature. However, there is nothing random going on there, except for the odd x-ray that comes in an produces a bit of oxidative stress here and there. (Among other EM frequencies.) In such cases- you might get cancer,but you won't get 'consciousness'. (Which in my opinion, is effectively a nonsense word. There is qualia, neural processing, modeling the world around us- planning, projection, wakefulness, etc. But consciousness is a catch-all similar to the word 'soul', and isn't well defined enough to be useful.) I find it comical that people continue looking for strange quantum effects in the brain, with the idea that somehow that randomness, if found, would allow for alternative possible futures.

    I find it likely that our *desire* to have choice / "free-will" has perverted our understanding of causality in general. To me; there is nothing that has shown the equivalence of past, present, and future- namely, there being only one of each. Not "multiple possible" futures.

    There is no reason to believe that human brains have some magic ability to "create different universes" in a fashion that other primates lack. And the slippery slope eventually reduces our ability to "choose" our future in the sense that we could have made some other decision at the same level a protist does. Or a rock. Maybe that rock is under pressure, and due to its internal bond patterns force carrier particles interacting with it- it splits in two.

    Einstein mentioned "In living through this "great epoch," it is difficult to reconcile oneself to the fact that one belongs to that mad, degenerate species that boasts of its free will. How I wish that somewhere there existed an island for those who are wise and of good will! In such a place even I should be an ardent patriot!" in a letter to Paul Ehrenfest. I feel the same way.
    Also, "I do not believe in free will. Schopenhauer's words: 'Man can do what he desires, but he cannot will what he desires,' accompany me in all situations throughout my life and reconcile me with the actions of others, even if they are rather painful to me. This awareness of the lack of free will keeps me from taking myself and my fellow men too seriously as acting and deciding individuals, and from losing my temper."

    People who think they get to decide what they believe baffle me. No matter how much money you gave me, or how much I *wanted* to believe it- I couldn't convince myself that 2+2 equals anything other than 4. Unless we are talking velocities, in which case.. sure. Its a little less than 4, depending on our units.

    It feels like we have choice. That should be good enough for anyone.

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