Doesn't this sound like a degenerate version of logical positivism to you? I think it would fall under scientism. I would add that this includes a confidence that what cannot be scientifically described does not matter (you see good examples of this in Economics, perhaps).
A while ago when we discussed this, I put up the Wikipedia list of the various forms of scientism, and I think I agree with most of them, including what you write above. In these debates, what bothers me is people (typically non-scientists) using the term "science" as a short-cut appeal to authority. I also tend to think of scientism as that [newer version of a perhaps old] attitude of arrogant dismissal that the user feels is guaranteed by the [imaginary] soundness and completeness (completeness in the sense in which you write above of what can be said, not in the sense of formal logic: the decidability of all possible sentences) of science.
Some might say that attitudes should not matter that much to us. I do believe it does in various ways: it closes our mind to reason (in the wider sense of that word... I think Gadamer wrote something, IIRC, regarding this: Reason in the Age of Science, or some such), it alienates us from the regular Joe (and makes him suspicious of us), it destroys the humanist identity within us (which ultimately, IMHO, is what makes us leftist), etc. Also, it is not just an attitude... often, it translates to a prescription: such as the recommendation, that Munevar talks about, to mothers in the so-called 3rd world to substitute breast milk with formula.
I should add however that I subscribe strongly to PKF's notion of opportunism. In that sense, I am not against using arrogance and bluster as a tactic, and would even recommend it (where you can get away with it) when addressing our right-wing adversaries, such as heaping ridicule on particular individuals or groups, in this tactical sense, for their belief in creationism etc. In that sense I am much less of an idealist or purist than some of our list-members like Yoshie or Doug (who worries about the principles of attacking Foley). ;-)
--ravi
P.S: I think many leftists may believe that Marx has given them a science of leftism (though, funnily enough, the mainstream seems to treat Marxists with the same sort of dismissal that is being meted out here to those who believe in astrology) and this affords them the luxury of dispensing with old-fashioned humanism (ack! another term I am using with artistic license!)... but the more I read Marx (on the recommendation of some of you) the more I feel that this is not true at all, as seen in even the few popular quotes from Marx that I have posted on previous threads.
P.P.S: my obsession with use and abuse of power and using that as a means of analysis is, may I point out, not just my own silliness and therefore easily ignored ;-), but is congruent with PKF's epistemological anarchism and Chomsky's brand of political anarchism. Despite his feigned naivete regarding pomo or Heidegger's "truth is the revealing of beauty", Chomsky in his political writing is very much, I claim, a small-t "truth" dude. His arguments are not Platonist, if I may add that to my litany of misappropriated terminology.
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