The only way to learn mathematics is to do mathematics.

Psychology is the science of mental life, not just the cataloging of its elements.

最强者也不能总是强大得足以永远作主人，除非他能把力量转化为权利和服从的义务。

Happiness in this world, when it comes, comes incidentally. Make it the objet of pursuit, and it leads us a wild-goose chase, and is never attained. Follow some other object, and very possibly we may find that we have cought happiness without dreaming of it.

作品总是在变化。

建筑师必须是公共领域的守护者。