经济学家的角色既是科学家，又是工程师。
The role of the economist is part scientist, part engineer.
对所有人有礼，与多数人交际，和少数人亲近，交一位朋友，不与人为敌。
We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.
Always be learning. The world changes fast, and you need to keep up.
几何学是关于永恒存在的知识。