A piece at NPR by Marcelo Gleiser elaborates on this. Gleiser writes:
I want to ... examine a ... controversial issue, one that has been in the limelight of cutting-edge physics for the past few years: Do some scientists hold on to a belief longer than they should? Or, more provocatively phrased, when does a scientific belief become an article of faith?This is all true, but it seems to fall afoul of much thinking today on matters of global warming, evolution, and the multiverse, the first of which seems to suffer from a dearth of empirical confirmation and the latter two of which lead to no experiments repeatable by others. Yet they're firmly held to be true by many scientists, and indeed they may be true, but the belief that they are is based more on faith than on empirical evidence and experimentation. Gleiser goes on to say that,
To talk about faith in the context of science seems quite blasphemous. Isn't science the antithesis of faith, given that it is supposedly based on certainties, on the explicit verification of hypotheses? This vision of science as being perfectly logical and rational is an idealization. Of course, the product of scientific research must be something concrete: Hypotheses must be either confirmed or refuted, and data from experiments should be repeatable by others.
There is, however, an essential difference between religious faith and scientific faith: dogma. In science, dogma is untenable. Sooner or later, even the deepest ingrained ideas — if proven wrong — must collapse under the weight of evidence. A scientist who holds on to an incorrect theory or hypothesis makes for a sad figure. In religion, given that evidence is either elusive or irrelevant, faith is always viable.The claim here is that it's dogmatic to hold to a theory in spite of the evidence and that such doxastic tenacity is characteristic of religious belief but is anathema among scientists. Yet surely Gleiser knows that the most deeply ingrained ideas, ideas that lie closest to the bone of our deepest metaphysical commitments, are rarely proven wrong in science. As Thomas Kuhn famously argued in The Structure of Scientific Revolutions, the old ideas only pass away when the scientists who hold them do.
When the beliefs people hold are entailments of their worldview those beliefs will not be surrendered unless the worldview itself shifts. And that tectonic intellectual event requires such a formidable expenditure of psychological energy and exertion of the will that it happens only infrequently among those who have reached their mature years.
If one's worldview demands materialistic explanations of phenomena, for example, then some materialistic explanation of a phenomenon will be clung to regardless of whether there's good evidence for it. The belief becomes a dogma, and scientists are no less likely to embrace dogma than are religious people. Examples of prominent scientists admitting to this are not hard to find. Here's a well-known admission from one of the world's top biologists, Richard Lewontin:
Our willingness to accept scientific claims that are against common sense is the key to an understanding of the real struggle between science and the supernatural. We take the side of science in spite of the patent absurdity of some of its constructs, in spite of its failure to fulfill many of its extravagant promises of health and life, in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism.In other words, defending materialism is more important than following the evidence. Evolutionary atheist and philosopher of biology Michael Ruse acknowledges that belief in evolution is actually religious, of all things:
It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counter-intuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is absolute, for we cannot allow a Divine Foot in the door.
Evolution is promoted by its practitioners as more than mere science. Evolution is promulgated as an ideology, a secular religion—a full-fledged alternative to Christianity, with meaning and morality. I am an ardent evolutionist and an ex-Christian, but I must admit that in this one complaint...the literalists are absolutely right. Evolution is a religion. This was true of evolution in the beginning, and it is true of evolution still today.The stereotype of the completely objective scientist persuaded only by empirical evidence and unencumbered by biases, preferences, and ideological predilections is hard to find in the real world, at least in those scientific fields which have profound metaphysical implications.