"No one may be asked to treat Darwin as a belief system not open to revision, but sometimes there is a tendency to do so, as with other 19th century giants, such as Marx. "So as not to gainsay Darwin" sounded as if Steve might be in danger of falling into that."

It does rather, doesn't it.

No it doesn't, and I've comprehensively explained why. This tiresome comment betrays the fact that you're a feckin' eejit. Nighty night!