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Systems science/theory and downward causation

  1. Oct 26, 2012 #1
    I've been reading a bit about systems science/theory and I understand that in some fields it sometimes pays off to look at how the whole systems behave as opposed to how the individual parts that comprise the systems work. However, there seems to be a certain aspect of systems theory known as "downward causation". This is defined as (from Wikipedia):
    There are also claims that because of this you could never simulate the system by simulating the parts and their interaction without considering this "action" (or force? I don't know what the right word is) that the system supposedly exerts on its parts.

    My knee-jerk reaction was that this is nothing but crackpottery. I have tried to find some mainstream hypotheses or experiments supporting such an idea but I only found philosophy stuff, which has neither.

    So, my question is: are there any hypotheses and/or experiments described in mainstream science literature that support this seemingly absurd idea of "downward causation" or is it just crackpottery?
  2. jcsd
  3. Oct 27, 2012 #2


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    Classical mechanics is separable meaning that classical phenomena are characterized by there being local properties that are only affected by other local properties. The kinematic theory of gasses is a good example of how a large aggregate of interacting molecules only depend on local fields and other interactions. Downward causation is impossible for any phenomena described by classical mechanical interactions, such as fluid waves, Rayleigh Benard convection, etc... Rayleigh Benard convection is a commonly used example of how "downward causation" might be of influence, but nobody in their right mind would believe such garbage. Quantum mechanical phenomena are not separable, and therefore are not subject to the same restrictions. Nevertheless, "downward causation" in quantum mechanics is not a particularly good concept to use even for those phenomena. There are lots of papers written about this. I'd suggest Karakostas, "Forms of Quantum Nonseparability and Related Philosophical Consequences" and "Holism and Nonseparability in Physics" by Healey.

    Note that this part however, is perfectly reasonable. Examining systems as a whole as opposed to individual parts is commonly done and perfectly valid. The only problem comes in when someone suggests there are downward causes that influence local physical states.
    Last edited: Oct 27, 2012
  4. Oct 27, 2012 #3
    Q_Goest's answer is excellent. Since the question is answered, I'll lock the thread.
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