PZ Myers and Laurence Moran say “Physicians and engineers are not scientists” (a point argued with, I think, malicious intent). Meanwhile Jerry Coyne and others think that car mechanics and plumbers are doing “science, broadly construed.” Sam Harris and Steven Pinker suggest (or at least imply) that scientists will ultimately overtake the humanities; Massimo Pigliucci has strenuously critiqued this latter view, calling it “scientism.”
This debate revolves around a basic rhetorical fallacy: the claim that “scientists” have a unique legitimacy attached to their beliefs, together with a claim of demarcational privilege to decide who is and isn’t a scientist. The arational imposition of intellectual privilege is, I think, the essence of the fuzzily defined “scientism” that non-scientists find threatening. It’s threatening because it is a threat. It attacks the legitimacy of entire classes of scholarship, and the Myers/Moran attack on engineers is one example.
This style of argument is used to de-legitimize a perceived opponent, or (as in Pigliucci’s case) to defend the legitimacy of his own profession. Such defenses are, according to Coyne, “defensive” — check out Coyne’s reaction to a historian who proposed that scientists might benefit from studying history. To paraphrase his position: we (scientists) don’t need you (non-scientists), you need us. On this level, the debate has nothing to do with science or the quality of ideas; instead it is a purely sophistic (and egoistic) effort to disqualify others.
I’ll pause now to remind the reader that I’m an engineer. Speaking as an engineer, I think there is a clear distinction between engineering and science: engineers have to actually get things right or they may suffer immediate economic, functional or ethical consequences. Scientists, on the other hand, have to pass their work through a process of critical review by their peers. The latter process is important to the long-term filtering of ideas, but peer review doesn’t have the same falsifying power as a collapsing bridge, an exploding boiler, a crashing train, a killer radiation leak or a misfired missile. So if we’re talking about legitimacy, I’d sooner trust the beliefs of a randomly selected engineer over those of a random scientist.
But Moran and Myers think engineers are something less. They are annoyed by Ken Ham’s claim that creationists can be successful in scientific careers, something that was argued during the Bill Nye / Ken Ham debate. They are so annoyed by the creationists that they are willing to degrade entire classes of scholars in order to win a fake point.