He was making an attack on reason himself. He allowed no questions regarding assumptions about geology and genetics and if he found himself unable to answer something he attacked the student who brought it up, saying that the only reason they would have to ask such a question is that they
obviously have no idea how science actually works and that they'd better talk less and listen more. A response of "hmmm, can't answer that now. I'll pass it around in the department and see what I come up with" would have be nice.
Once we had it through our heads that we were to simply shut up and accept what we were told he became almost liveable again.