One thing I always found slightly sad about this movie is the idea that humans can only advance through outside intervention. I don't believe that at all!
I agree. It struck me re-watching this movie recently that it invokes a "sky-hook"-type explanation for human cognitive development. This occurred to me during the opening scenes, but it didn't detract from the power of the film. These types of explanations are very satisfying, for some reason.
(I guess you could also ask what was responsible for the cognitive development of whatever planted the monoliths..)
