lays it all out rigorously. Uh huh. I have tried to dig into his book a couple of times, but to no avail. As best I can make out, I'd summarize his claim like this: "because we don't know how something happened, it must be impossible". This strikes me as an awful failure of imagination, but maybe it's just me.
"I'd summarize his claim like this: 'Because we do not know how something happened, it must be impossible."Then you have not read the book. Here is one of many statements he has made concerning the compatibility of design theory with many concepts of evolution.
"Where does this leave special creation and theistic evolution? Logically speaking, Intelligent Design is compatible with everything from the starkest creationism (i.e., God intervening at every point to create new species) to the most subtle and far-ranging evolution (i.e., God seamlessly melding all organisms together in a great tree of life). For Intelligent Design the first question is not how organisms came to be (though this is a research question that needs to be addressed), but whether they demonstrate clear, empirically detectable marks of being intelligently caused. In principle, an evolutionary process can exhibit such "marks of intelligence" as much as any act of special creation."
So, Dembski is not denying that macroevolution is possible, only that the evidence and arguments brought forth for it are weak, especially when compared objectively to the evidence and argument presented by ID.
Here he elaborates further. The print is large and eye strain should therefore be minimal.