#13 Or is disagreeing with you not allowed ...?
I'm sorry if I sounded too dogmatic.
Bion: yes, "denied them rationality ..." is a possibility that I hadn't thought of, and its rightness is borne out, obviously, by the examples of "sense 2" in #17.
On reflection, I think the (or my) problem with wupper's "denies them their ability to act rationally" is the possessive, "their". You often have this with sense 1, e.g. to deny people their rights, but in sense 2 you're talking about something that those concerned allegedly have not got -- "any talent", "rationality", etc. You'd be less likely to say that Aristotle and the others denied animals their rationality -- or, indeed, that "he indirectly denies [the Russians] their rationality of behaviour".
I think that was why wupper's sentence so strongly suggested "sense 1" to me.