The worth of a state， in the long run， is the worth of the individuals composing it.

The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry.

悔恨自己的错误，而且力求不再重蹈覆辙，这才是真正的悔悟。