Sunday, May 23, 2010

Command or Description?

This post is part of my series on free will.

Early scientists like Isaac Newton believed they were discovering the principles by which God governed his creation. Such "laws of nature" were absolute; they admitted no exceptions and could not be broken. A similar vein of thought can be found in Einstein: "I want to know God's thoughts; the rest are details," and in modern theoretical physics, where some speak of an ultimate theory, a Theory of Everything (TOE).

According to another vein of thought, the laws of nature are descriptions, not commands. They are a way of organizing a large body of observations according to the regularities found among them. They are mathematical models that capture some aspect of reality. This view acknowledges that such laws are always provisional and approximate. There will always be some realms - some scales of size or energy - in which the known laws have not been tested, and in which they may well fail to be exactly true.

Many philosophers of free will seem to adhere to the seventeenth-century view of the laws of nature. This is especially evident in their discussions of determinism. There are, it is assumed, some ultimate Laws that, God-like, determine everything that will ever happen.

An exception is the philosopher Norman Swartz, who argues that if we take seriously the view of laws as descriptions, not commands, then the problem of free will  does not even arise. I am not completely persuaded by his argument: read it yourself and see what you think. But I agree that thinking of laws as descriptions is an important step in the right direction.

These issues leap to the foreground in discussions of quantum mechanics. If we take the mathematical formalism of quantum mechanics to be an absolute command that admits no exceptions, then we are driven to a metaphysically absurd interpretation (the Many-Worlds Interpretation). But if we admit that quantum mechanics is merely the most accurate description we can give of certain systems, then such absurdities aren't necessary.

I see the significance of this view for free will in the possibility that there is more than one description of a certain event that is (approximately) a true description. The existence of a (valid) description at the level of electrons does not rule out the existence of a (valid) description at the level of mental events.

I will return to this point next time.


  1. I think this gets a bit close to a view I find very perplexing. This is the radical sort of scientific instrumentalism that says something like "Well no scientific theories are about fact, they just describe models. There's no such thing as an electron, it's just a mathematical concept we use to describe certain tracks that appear on photographic plates attached to particle accelerators etc."

    There are a surprising number of scientists (a lot of them particle and QM physicists which is no coincidence!) which espouse this view and I don't understand it at all. It's almost like what the Aristotelians told Galileo -- we'll accept Copernicanism as a convenient calculating device but who would hold these equations to be true?!

    (I also think this has at least some parallel to your views on the metaphysical status of the wave function.)

    My view is this: every natural law is a command. Our sciences are models which attempt to approach this command. So theories are descriptions of the command. But this does not mean they have some special status of descriptions-only. If they have replicated the command then they are not mere calculations but show us what actually happens.

    Just wondering what you think is wrong with this?

  2. If they are commands, who is commanding them? In Newton's day, the answer would have been obvious: God. But I see a big red A on your blog, so I assume you don't mean that.

    Is there a Theory of Everything that just exists Platonically on its own somewhere "out there," that gives "commands" that cannot be obeyed? I doubt it. Rather, I think the universe exists: we can observe it. And there are regularities in the behavior of the universe and its constituents that we can try to capture in mathematical models.

    I don't see why "descriptions-only" should be seen as a "special status." I can describe my friend to you, but I don't think - and you shouldn't think - that I have thereby captured his inmost essence, who he truly is. Why should it be any different for an electron, or a galaxy?

    But (to go beyond analogies) I think QM is where we really see that our best models CAN'T capture the essence of what is truly going on. It's hard to think in terms of commands when your theory only says things like, "The electron might be here, or it might be over there, or, really, anywhere in between."

    The alternative is to declare that the theory is correct, it's reality that is only an approximation - as in the MWI. But if our goal is to describe the universe as accurately as we can, that approach is totally backward.

  3. Um, that should have been "cannot be disobeyed" in the second paragraph. Isn't there any way to edit comments here?

  4. Of course commands is a metaphor -- rather than a Theory of Everything that gives commands for everyone to obey it's more like the Universe of Everything that implements the commands themselves. The question is not whether you have captured the essence of say your friend but that your description is an attempt to capture an essence that you believe exists. It is not the description of just the isolated friend-like sensory data on your visual cortex but of your actual friend, even if the description doesn't match reality perfectly.

    Whilst we don't think that any theory we have captures everything completely, we still think it's true, eg. if m=m0/sqrt(1-v^2/c^2) then that's what m actually is. It is the way the universe works and more than just an equation just in our heads. If it turns out it's v^3 or something else then we were wrong about reality.

    On QM, since all interpretations give the same accuracy of descriptions they should all fulfill your goal equally, MWI included! In fact by being so opposed to the reality of the MWI I think you're merely making the case that you think a good theory describes reality and you reject MWI because you don't think it describes reality :)

  5. If by "commands" you mean "whatever the universe does" and by "theories" you mean "(approximate) descriptions of whatever the universe does", then I think we're saying the same thing.

    I don't think "command" is a particularly apt metaphor if no one and no thing is doing the commanding. And, as I said, the commands of QM aren't "Electron, go over there!" They're more like, "Electron, you may go there or there or there...." Not very command-like.

    So I think "description" is more accurate and less misleading.

    a Nadder: In fact by being so opposed to the reality of the MWI I think you're merely making the case that you think a good theory describes reality and you reject MWI because you don't think it describes reality.

    Me: Yes :)