"So is the denial of design (or perhaps the failure to mention design) a necessary condition for doing science?"
No. What's necessary for doing science is to follow scientific method. Victor, you don't seem to understand why ID is shunned by the scientific community. It isn't because it is based on religious beliefs. It is because of the fact that it isn't science.
In science, you have to be driven by the evidence. The folks from DI are driven by their beliefs. They search for evidence to support what they already believe. That's not scientific method, because it leads them to ignore evidence that doesn't fit their objective. If you ignore evidence, you can't hope to move scientific understanding forward.
OK, let me see. I think most of us would say that Richard Lewontin is a scientist, right? Here's what he wrote. Now you may agree with it or not, that's not the point. The point is, that if you are driven by your beliefs, you'll ignore evidence that doesn't fit your objective, right? You've seen the quote, surely.
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 an 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.
Now, based on this, how can anyone use the reasons you provided for denying that ID is science, and also say that Lewontin is also doing science. Or is it that you can't reason from pre-established beliefs so long as they are materialist pre-established beliefs?