I remember at least one Pali sutta in which the Buddha said that some monks are capable of the highest attainments through meditation and others through reasoning, and that both paths should be equally regarded. I'd have a hard time finding that sutta now, but I'll give it a try, if you like. Edit: Or maybe my memory fails... Edit 2: Related, I think- http://en.wikipedia.org/wiki/Nirvana...the_Pali_canon But I am straying off-topic a bit. The question was about realizing anatta, not nibbana. I'm not sure how anatta could be realized without reasoning, but I think I'll stop short of saying that it is sufficient in itself. I think the two kinds of knowledge are distinct, one cerebral and the other visceral, for lack of a better word. What do you think, Deshy?