You write “My own view is that being personally and emotionally attached to one’s own theories, whether for religious or ideological or other non-scientific reasons, is not necessarily a bad thing as long as there are social mechanisms allowing scientists with different scientific viewpoints an opportunity to make themselves heard.” And “My favorite example of the importance of personal belief in, and commitment to the truth of, one’s own theories is Galileo.”
Since the Enlightenment everybody knows that science is about knowledge and that religion is about belief. Galileo never pleaded for belief, just the contrary: “I shall never be able to express strongly enough my admiration for the greatness of mind of these men who conceived this [heliocentric] hypothesis and held it to be true. In violent opposition to the evidence of their own senses and by sheer force of intellect, they preferred what reason told them to that which sense experience plainly showed them ... I repeat, there is no limit to my astonishment when I reflect how Aristarchus and Copernicus were able to let conquer sense, and in defiance of sense make reason the mistress of their belief.” (quoted in Popper, 1994, p. 84)
All great scientists pleaded for the utmost degree of objectivity and that meant to rule belief, passion, and the other human-all-too-human excuses out. Science is about true/false and that is that: “Like Planck, Einstein viewed the human element of any physical theory as essentially arbitrary, something that should be purged on realization of the final true theory.” (Mirowski, 2004, p. 159)
Galileo was well aware that most of those who pass as scientists are not up to the task. “These savants, as Galileo put it, first decided how the world should function in accordance with their preconceived principles. ... He openly criticized scientists and philosophers who accepted laws which conformed to their preconceived ideas as to how nature must behave. Nature did not first make men’s brains, he said, and then arrange the world so that it would be acceptable to human intellects.” (Kline, 1982, p. 48)
Galileo did not excuse incompetence and proto-science with passionate belief. He wanted to throw these guys out of science. And as far as physics is concerned he succeeded. In economics, things are a bit different. There is a lot of self-delusion: “Economists think of themselves as scientists, but ... they are more like theologians.” (Nelson, 2006, p. xv)
Genuine scientists like Feynman subsumed economics squarely among the cargo cult sciences. This got not lost with Clower: “Suffice it to say that, in my opinion, what we presently possess by way of so-called pure economic theory is objectively indistinguishable from what the physicist Richard Feynman, in an unflattering sketch of nonsense ‘science,’ called ‘cargo cult science’.” (1994, p. 809)
Science, we know it from Popper, is ‘conjecture and refutation.’ We know also that conjectures often turn out to be false. And here the great divide between science and mere belief systems becomes clearly visible. The idea of science necessarily includes accepting a refutation. That does not happen in economics: “In economics we should strive to proceed, wherever we can, exactly according to the standards of the other, more advanced, sciences, where it is not possible, once an issue has been decided, to continue to write about it as if nothing had happened.” (Morgenstern, 1941, pp. 369-370)
The question between New Classics and New Keynesianism has been decided. Both are indefensible. If economics was a science both Romer and Lucas would quietly say Good Bye.
Clower, R. W. (1994). Economics as an Inductive Science. Southern Economic Journal, 60(4): 805–814.
Kline, M. (1982). Mathematics. The Loss of Certainty. Oxford, New York: Oxford University Press.
Mirowski, P. (2004). The Effortless Economy of Science? Durham, London: Duke University Press.
Morgenstern, O. (1941). Professor Hicks on Value and Capital. Journal of Political Economy, 49(3): 361–393.
Popper, K. R. (1994). The Myth of the Framework. In Defence of Science and Rationality., chapter Science: Problems, Aims, Responsibilities, 82–111. London, New York: Routledge.
Feynman-integrity first of all demands to listen to what he said about economics. For a short overview see The Farce That Is Economics: Richard Feynman On The Social Sciences.
Economics could get out of its current proto-scientific state if Flat-Earthers now turn to a socially more productive engagement, e.g. looking at Game of Thrones and such.
For details of the big picture see the cross-references Scientific Incompetence.