数学不是一门演绎科学——那是陈词滥调。当你试图证明一个定理时，你不仅仅是列出假设然后开始推理。你所做的是反复试验、实验和猜测。
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.
The course of history is the slow march of freedom.
设计中最难的部分是保持功能的简洁。
译文：借鉴前代兴衰，考察当下得失。《通鉴》的写作宗旨，直指现实关怀。