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Mathematics is not a deductive science—that's a cliché. When you try to prove a theorem, you don't just list the hypotheses and then start to reason. What you do is trial and error, experimentation, guesswork.

在別人面前受稱贊，不如背后沒有人說壞話；與人相處能使人獲得短暫快樂，不如與人長久相處而不使對方厭惡。

In looking for someone to hire, you look for three qualities: integrity, intelligence, and energy. But the most important is integrity because if they don't have that, the other two qualities, intelligence and energy, are going to kill you.

All men are immortal， but those who are not educated are immortal in a lower and less enviable sense.

一本正經地對待消遣和刻板地追求學問，結果就會成為一個學究。