数学是为不同事物赋予相同名称的艺术。
世界始于人类之前,也必将终于人类之后。
愛とは、相手を理解しようとすることだ。
"The truth is a mirror, and the mirror is a shadow."
健康不是富人的特权,却是穷人的脆弱点。
We begin with the hypothesis that any subject can be taught effectively in some intellectually honest form to any child at any stage of development.