Alright, Mark has successfully baited me into a response on the issue of scientism. I should begin by saying that Mark has an interesting reading of Dennet that makes him out not to be a reductionist (as I and many others interpret him). I won't address that here; I'm more interested in the general question of the influence of scientism on well-educated, intellectually curious people.
As I've said before, I think scientism -- the idea that science is applicable to any domain of inquiry that is meaningful, and will inevitably provide a solution to all meaningful questions -- is a much more pernicious cultural force than does Mark. In fact, I think it's the popular religion of most smart people (even of many people who also consider themselves moderately religious). The other popular religion for educated people is cultural constructivism (or something of the sort) and accompanying relativism and postmodernism: it shares with right-wing religious fundamentalism an overly dismissive attitude towards science (see this article on how the right has co-opted this approach in its resistance to science). I'm not a fan of this extreme either; but it doesn't have the same influence outside the university that it does within it. It's quite hard to find an educated person who isn't significantly influenced in one of these directions.
Scientism is part of a cultural milieu in which the role of the humanities and interiority in general have been devalued. There can't be any dispute that philosophy and literature simply does not have the same value today (within the university and without) as the sciences; that most people think of philosophy as a kind of bullshitting that science will do away with; and that talking to a therapist about one's problems seems to many a patently absurd, farcical idea in light of the fact that we can talk instead about the brain (and, today in very clumsy ways, act directly upon it with drugs). In fact, it's all a form of anti-intellectualism of the same sort as we see in religious fundamentalism: science promises to do away with the need to reflect. Again, that the only cultural force really countering this trend is obscurantist postmodernism and limited to the university just makes it worse.
Because of the prevalance of such values, otherwise well-educated Americans tend to be poorly educated about philosophy. And they believe a bunch of things (such as the idea that values can be justified empirically) that are just as stupid and infuriating as the idea that the earth was created 4,000 years ago and we walked with the dinosaurs. I'm equally intolerant of all of it. Arguably, the dominant cultural force in the United States is religious fundamentalism; but it's almost balanced out by the secular and moderately religious left. And because I identify with the latter, it's their delusions that I care about and would like to see corrected. It's the fact that a bunch of smart, well-educated people believe a bunch of crypto-religious nonsense that's fed to them under the banner of science that really irritates me. These are the people I hang out with and talk to. So I don't find myself a missionary out to preach science to the religious; it's the people who have purportedly accepted the same rules as me, who are playing the same game, that I care about. So that's an explanation of why I care more arguing about this sort of thing (whereas I see that battle against religious fundamentalism as political).
Of course, the assessment of the cultural force of some view -- which seems to be the point of disagreement here -- is a difficult sort of argument to make. It depends on one's sensitivities, habits of cultural exposure, and the orientation of one's spleen. Where I see scientism cropping up in pernicious ways in public and intellectual discourse all the time, Mark does not. And one could point out that I've made the kind of "the world is going to hell in a hand basket" argument that I usually decry (although really my view is that the world has always been in the hand basket and has remained at a relatively constant (but uncomfortably close) distance from hell). But I think it's safe that Massimo Pigliucci, an evolutionary biologist by trade and philosopher in his spare time (who seems to agree with me about the pernicious effects of scientism), is a minority among scientifically minded public intellectuals. Most scientists making public comment on philosophy and religion are simply saying dumb things. Pigliucci is part of a small pocket of resistance within that community. And a voice of reason. And to get an idea of how irrational things get, go to a site like ScienceBlogs and look at relevant posts (and comments). Scientism is what leads the world's resident genius to make the stupid claim that "philosophy is dead." That's an embarrassment that broadly educated scientists like Pigliucci care about. Scientism is what makes it possible for someone like Sam Harris to be taken seriously on morality, despite the fact that his arguments flunk philosophy 101. That intellectually curious people are influenced by that kind of stuff (and freebase it regularly via TED lectures) is a crime. They're better off with "The Secret."
For a more extended argument of this sort, see Marilyn Robinson's Absence of Mind: The Dispelling of Inwardness from the Modern Myth of the Self. See also Tom Sorrell's Scientism: Philosophy and the Infatuation with Science.
-- Wes Alwan