Sory for interferring, but in my opinion Quintanians had to be intelligent. Didn't they negotiate with the Earth ship's crew?
Of course, it could have been some other form of intelligence; for example it is safe to assume, that the certain group of Quintanians might be called ,,intelligent'', whereas the individuals are not intelligent (by the means of human understanding).
One more thing. I don't think the world ''evil'' (as used by father Arago) could describe any unhuman being. The evil itself is a human concept, based on some features of a human soul and is (evil) strongly connected with the ability to criticise individual human acts. It is highly unlikely for Quintanians to be similar to humans in any way; therefore the conception of evil itself is, I think, unadequate.