Richard Lewontin, a leading evolutionary thinker, made an interesting admission as to how the commitment to how he wants to see the world (materialism / naturalism) actually determines his findings as a scientist.
“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."And here's the startling admission:
"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 own a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, not matter how counterintuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is absolute, for we cannot allow a divine foot in the door.”
~ Richard Lewontin in New York Review of Books, January 9, 1997, p. 28.