[jamesbritt]

That was my reading of the assertion, and similar claims that everyone, excepting the obviously retarded, can potentially (assuming effort + time) achieve the same level of intellectual mastery.

Is it somehow impolite, or demonstrably incorrect, to assert that there are people who are in fact stupid? Or people who are quite functional but not particularly bright? That there are people who, through no fault of their own, could never achieve certain intellectual goals no matter how much time or effort because they are simply not mentally capable?

Life experience tells me otherwise.