Saturday, August 17, 2013

Confusing reductionism, determinism and materialism

One can hold one or two of the above doctrines without holding the other one or two. Some commentators here seem confused about this.

To get this clearer it may be helpful to consider the case of Hayek. He was certainly a materialist, and probably believed in physical determinism as well. But he was definitely anti-reductionist. He believed that due to complexity, there existed emergent properties at higher levels of organization that could not be reduced to the sum of their parts. But he still thought that they were material in nature through and through (there was no new substance like spirit or mind that entered into the picture to create the emergent level), and that their behavior was probably deterministic, even if impossible to predict exactly.


  1. Are you are assuming that once a system manifests emergent properties it is no longer simply the sum of it parts?

    As "the sum of its parts" is a bit of a vague term I suppose it would be possible to define it to exclude systems that manifest emergent properties but this seems a bit arbitrary.

    If a complex system is both deterministic and manifests emergent properties then in theory at least it should be possible to analyze all the parts and see how they combine to produce the whole. Surely this would mean that it had been explained by a reductionist methodology ?

    1. Rob, I am giving a very standard view of what emergence means:

      "The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity. At each level of complexity entirely new properties appear. Psychology is not applied biology, nor is biology applied chemistry. We can now see that the whole becomes not merely more, but very different from the sum of its parts." (Anderson 1972) -- from the Wikipedia page on emergence

    2. The idea of emergence is, in fact, One of the main ways in which materialists have attempted to get around the problems inherent in reductionism. I am not saying anything novel in claiming this: see the literature on chaos and complexity.

  2. It is obviously true that in many systems "At each level of complexity entirely new properties appear". For example, there are properties in biology that don't exists in chemistry.

    If reductionist are people who would deny this then the evidence seems to be against them.

    I'm pretty sure that most biologists would not qualify as reductionists, so defined. I just thought your original post was making a deeper claim than "the beliefs of most biologists confirmed again by the facts"

    Perhaps in retrospect I just misread the intent of your original post.

    1. 'It is obviously true that in many systems "At each level of complexity entirely new properties appear".'

      Good, You're not a reductionist. For a contrary view, See Alex Rosenberg, Who denies that You even have the belief you expressed above. Blame Siri for the weird capitalization here.

    2. I think that the terms "emergent properties" and "Reductionism" have been defined in such a way that precludes reductionist views being used to explain systems with emergent properties.

      I think these definitions are in someways helpful to describe the world. But they are just definitions.

      In a fundamental way the properties in biology must emerge because the properties in chemistry allow them to and this can't be defined away.


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