Natural experiments can provide valuable insights into economic questions.
行为不仅仅是一种反应，更是一种沟通。
任何牺牲基本自由以换取短暂安全的人，最后既得不到安全也得不到自由。
铁蛋儿的问题，不是他不识字，也不是他不会思考，而是他不知道什么是思考，并且将其与感觉相混淆。
Quality is not a title; it is a behavior.
The true teacher defends his pupils against his own personal influence. He inspires self-trust. He guides their eyes from himself to the spirit that quickens him. He will have no disciple.
人は、自分が信じるもののために戦う。
Millions saw the apple fall, but Newton asked why.