From revised version of The Measurement Problem:
As used in this paper, “believe in” just means to “accept as true.” When I use the phrase to characterize a survey item relating to evolution or global warming, “belief in” conveys that the item certifies a respondent’s simple acceptance of, or assent to, the factual status of that process without assessing his or her comprehension of the evidence for, or mechanisms behind, it. I do not use “belief in” to align myself with those who think they are making an important point when they proclaim that evolution and climate change are not “mere” objects of “belief” but rather “scientifically established facts.” While perhaps a fitting retort to the schoolyard brand of relativism that attempts to evade engaging evidence by characterizing an empirical assertion as “just” the “belief” or “opinion” of its proponent, the “fact”–“belief” distinction breeds only confusion when introduced into grownup discussion. Science neither dispenses with “belief” nor distinguishes “facts” from the considered beliefs of scientists. Rather, science treats as facts those propositions worthy of being believed on the basis of evidence that meets science’s distinctive criteria of validity. From science’s point of view, moreover, it is well understood that what today is appropriately regarded as a “fact” might not be regarded as such tomorrow: people who use science’s way of knowing continuously revise their current beliefs about how the universe works to reflect the accumulation of new, valid evidence (Popper 1959).