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.
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.