自由是一个沉重的负担，是精神承担的伟大而奇怪的负担。
Freedom is a heavy load, a great and strange burden for the spirit to undertake.
The study of mathematics is like air or gravity – it’s everywhere, even if you don’t see it.
写作是一种乐观的行为。如果你觉得它不重要，你就不会费心去做。
Peace is the highest good， because it is the state in which the mind is most fully in accord with its nature.
Land is a peculiar commodity, which is different from all others, and the quantity of it is always fixed and limited.
计算机科学的挑战不仅在于创造新技术，还在于确保它们被道德和负责任地使用。