UndercoverElephant
Pachyderm of a Thousand Faces
- Joined
- Jan 17, 2002
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One word: supervenience.
And when you explain to me what a stupid, incoherent concept that is, be sure also to expalin why so many philosophers take it seriously. Otherwise, not being a philosopher myself, I might just assume the experts know what they are talking about.
http://plato.stanford.edu/entries/physicalism/#2
This is what supervenience is with respect to this debate:
In attempting to answer the completeness question, it has become customary since Davidson 1970 to look to the notion of supervenience. (The notion of supervenience is historically associated with meta-ethics, but it has received extensive discussion in the general metaphysics and logic literature. For a survey, see Kim 1993.)
The idea of supervenience might be introduced via an example due to David Lewis of a dot-matrix picture:
A dot-matrix picture has global properties -- it is symmetrical, it is cluttered, and whatnot -- and yet all there is to the picture is dots and non-dots at each point of the matrix. The global properties are nothing but patterns in the dots. They supervene: no two pictures could differ in their global properties without differing, somewhere, in whether there is or there isn't a dot (1986, p. 14).
Lewis's example gives us one way to introduce the basic idea of physicalism. The basic idea is that the physical features of the world are like the dots in the picture, and the psychological or biological or social features of the world are like the global properties of the picture. Just as the global features of the picture are nothing but a pattern in the dots, so too the psychological, the biological and the social features of the world are nothing but a pattern in the physical features of the world. To use the language of supervenience, just as the global features of the picture supervene on the dots, so too everything supervenes on the physical, if physicalism is true.
It lists four problems with this position. The first three aren't that important to me but....
4. The necessary beings problem
(Cf. Jackson 1998) Imagine a necessary being -- that is, a being which exists in all possible worlds -- which is essentially nonphysical. If such a non-physical being exists, it is natural to suppose that physicalism is false. But if physicalism is defined according to (2), the existence of such a being is compatible with physicalism. For consider: if the actual world is wholly physical, apart from the necessary non-physical being, any minimal physical duplicate of the actual world is a duplicate simpliciter. Since the non-physical being exists in all possible worlds, it exists at all worlds which are minimal physical duplicates of the actual world. So we seem to face a problem: the existence of the non-physical necessary being entails that physicalism is false, but the definition of physicalism permits it to be true in this case.
This problem is not so easily answered as the previous three. Lying behind the problem is a deeper issue about the correct interpretation of necessity and possibility......
Remember in a previous discussion you ended up not understanding the difference between neccesary and sufficient? Well, here's the same problem all over again - and the experts are agreeing.
.... -- the modal notions one uses to formulate supervenience. On one way of interpreting these notions, the existence of a necessary being of this sort is incoherent. A reason is that it would violate David Hume's famous dictum that there are no necessary connections between distinct existences -- the being is distinct from the physical world and yet is necessitated by it. On another way of interpreting these notions, however, there is nothing incoherent in the idea of such a being. The correct way to think about modal notions, however, is a topic that is well beyond the scope of our discussion here. The problem seems to be that the supervenience definition of physicalism in effect presupposes something like Hume's dictum, in that it uses failure of necessitation as a test for distinctness. But this means that someone who denies the dictum will have to find an alternative way of formulating physicalism.
In other words, supervenience physicalism isn't physicalism. Instead, it's physicalism with something added. What's been added? Being. How can the physicalist respond to this? He can't. He's back to square one. Up a ladder. Down a snake.
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