Q,
In most places I've seen where the physicalism was attacked or defended, it was in the terms of the supervenience (i.e. that metaphysically there is no difference without physical difference). Be it when physicalism is being attacked, or really defended by the physicalists. E.g. in relation to the zombie argument, or to the Jackson's knowledge argument.
But if you want to use "physicalism" synonymous with "naturalism", I can't really stop you. I guess we should then distinguish the discussions about "physicalism" in one sense, and "physicalism" in another sense. :) But anyway, zombie argument is not supposed to be against what you describe as "physicalism", so to argue that zombie argument fails to give arguments against it, is to miss its point.
Anyway, it seems to me that what you are describing is empiricism of Quinean type, and not physicalism.
Sorry Dan,
Let me try to explain those words, as they are very important for the zombie-argument to makes sense.
"Metaphysical" when talking about "metaphysical necessity" (or possibility), means that some claim is true, not because it happens to be a fact in this world, but that it is contradictory for it to be otherwise. An example would be e.g. that it is metaphysically necessary that if you have one and one more apple, you have two apples. So, when we talk about this kind of metaphysical necessities, we can have as examples truths from logic, mathematics, conceptual necessities (e.g. if we define bachelor as an unmarried male, it would be contradictory to claim that some bachelor is not male), etc... Because metaphysical truths are supposed to be true independent of the how the world happens to be, you don't need to know any particular fact from the everyday experience in order to know them, so their knowledge is independent from knowledge gained from particular experience, and that is what that other term - A PRIORI means.
The physicalist claim is now, that the facts about there being consciousness and exactly what consciousness it is, are metaphysically necessary given the physical facts about the same system. So, basically one claims that facts about consciousness follow (as in logic/math etc..) from physical facts (a priori). So, for physicalism the truth about consciousness relation to physical IS of the same nature as the nature of math truths, i.e. independent of the way the world happens to be.
Hope this helps.
Oops, that should be "metaphysically, there is no difference without physical difference". Sorry about that.
Hi Q,
Science doesn't, and naturalism doesn't (commit to the claim that one can a priori get from physical facts to the facts about consciousness). But that is THE commitment of physicalism. Physicalism is not equal to science. It is just yet another metaphysical position. Physicalist's position is usually defined that metaphysically there is no difference without metaphysical difference. And the metaphysical necessity is a priori necessity. (Some try to say that physicalism doesn't need to claim a priori necessity, but only Kripkean a posteriori necessity, but that is , seems to me, really just hiding the commitment of a priori deduction. I could say more on this, if needed).
So, when person presents zombie argument, he doesn't give argument against science, nor physics, but against this metaphysical commitment of physicalism (defined as "no difference without physical difference). I wonder if lot of negative reactions to the zombie argument in this series of post is mixing up the naturalistic/scientific view on the world with the claims of physicalism. (Of course there is also the silly consequences of the epiphenomenalism, but as I said, we can take that as a reductio.)
This was very funny...
On more serious not, there is nothing wrong with zombie argument. It just says that physicalism claims that you can a priori deduce the facts about conscious experience (e.g. if there is conscious experience/exactly what kind of conscious experience there is) from the physical facts about the system. Notice that 'a priori'. So, it is not just that we can come to know which physical facts are correlated with what facts about consciousness, or which physical phenomenon gives rise to consciousness, but that we can deduce like we deduce mathematical truths.
So, zombie argument just says, that given what our idea of physical system consist of now - i.e. the patterns of behavior of complex structures of elementary physical particles, governed by physical laws which take form of mathematical equations... you can't deduce anything like facts about conscious experience. So, it says, there is no way, without the knowledge based on the science which would relate this behavior to our conscious experience, that one could go from the description expressed in mathematical equations which relate different measurables of the systems, like position, energy, momentum, etc..., and A PRIORI deduce facts, like if there is conscious experience, or the facts about what kind of conscious experience one has.
"But 'physical' is not just what we know about the world now, it means everything that will be approachable by physical science in future also!"
Well, that's OK, but if those equations are still nothing but mathematical equations which show how different measurables relate, there is no way to start from THAT, and a priori deduce facts as e.g. there being conscious experience, or the facts about it. Again, it is not if we can scientifically know based on the physical facts if there is, or not conscious experience, and know again based on scientific research what kind of conscious experience there is.
It is about impossibility to deduce a priori this conscious experience, from descriptions which are in terms of concepts which are incommensurable with conscious experience. We might as well, try to deduce the mass of Earth solely from the Pythagorean Theorem.
"But... epiphenomenalism, the view that consciousness is epiphenomenon is silly"
Yes, it is. But that the zombie argument starts from some position taking some assumptions of physicalism and refusing others, and as a result has epiphenomenalism as conclusion, is nothing but reductio ad absurdum of those other assumptions which epiphenomenalism shares with physicalism.
Anyway... hope I don't spoil everyone's joy with the post, as it was pure comedy gold!
Q,
I'm not sure you insist of calling this combination "physicalism", contra all those discussions of physicalism in philosophy. First, one can be empiricist and scientific realist, and not be physicalist. For example there is nothing contradictory in thinking that the all the beliefs are revisable in the light of new empirical data, and also believe that sciences give us explanation of the real world, and still not believe that that the mental phenomena can be deduced from the physical facts. Of course you may be a physicalist, who also is scientific realist and Quinean empiricist, but it is good to keep on mind that those are not equal.
You point to the status of disciplines like math and logic, but it is not just that. Biologists and cognitive psychologists are scientists no? But they don't have to have any particular belief of how the phenomena they research are related to the level of e.g. elementary particles.
I would point to what Caledonian said... "What scientists DO presume is that the world can in some measure be described and understood."
I think that nicely captures the science in general as not committed to a certain metaphysical view.