At Thoughts in a Haystack, Pieret notes that Citizens For Objective Public Education, Inc. (COPE) has brought a lawsuit in Kansas to block the implementation of Next Generation Science Standards. (The whole complaint is here (PDF).) The complaint alleges that teaching evolutionary theory amounts to state endorsement of atheism, and hence is unconstitutional.
“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. 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. The eminent Kant scholar Lewis Beck used to say that anyone who could believe in God could believe in anything. To appeal to an omnipotent deity is to allow that at any moment the regularities of nature may be ruptured, that miracles may happen.”
Firstly, this passage is taken out of context; read in context, it is fairly clear that Lewontin is attributing this dogmatism to Sagan, and not endorsing it himself.
Secondly, everything here depends on what Lewontin means by “a priori”. Since he does not tell us what he means, we are left to our own devices. But it is worth pointing out that Lewis White Beck, the Kant scholar mentioned here, was strongly influenced by the once-prominent (and now unjustly forgotten) philosopher C. I. Lewis. One of Lewis’ considerable achievements was the invention of what he called “the pragmatic a priori,” on which a priori statements are those that hold independent of experience because they are freely chosen by us in order to enable those inquiries that satisfy our needs and interests.
For this reason, when Lewontin claims 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.
we can take this as meaning something like the following:
In order for us to build more or less reliable and provisional models of causal regularities that account for available data, we must assume that the causal regularities are not alterable by divine whim. For if we could not determine whether any particular event was in accord with or in violation of the laws of nature, the very notion of “a law of nature” would loose all sense.
On Lewis’ account of the a priori, we are not “dogmatically” committed to this conception of the causal order; we chose this principle in order to do science at all. If, in the course of inquiry, we found that our inquiries were unsuccessful because of this principle, we could chose to revise it.
On reflection, I think it is fairly clear that Lewontin is attributing to Sagan the ‘dogmatic’ version of the a priori, and I don’t know whether Lewontin himself would accept the pragmatic version. But I mention this because the pragmatic a priori has merits of its own worth consideration, including a better understanding of what distinguishes “methodological naturalism” (the pragmatic a priori) from “metaphysical naturalism” (the dogmatic a priori).