A “rigorous” education is for me one that saves souls one at a time and pulls that soul out of his socio-economic context, whatever that is, and gives him an “out of body” experience, so to speak. It frees him from his passions or at least puts him at odds with them, makes him aware of the assumptions underlying the arguments swirling around him, causes him to recognize and detest cant and mediocrity, and establishes in him an insatiable hunger for whatever is good and true and beautiful. It gives him a star to follow, whatever the crowd is doing. Makes him a Magus.
The italicized portion is, for me, the primary and most difficult aim of education. Plato sought it, Augustine sought it, Calvin sought it, and all wise educators today seek it.