对中国国民党同志共勉，1920年1月1日

The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.

好奇心是所有伟大数学发现背后的驱动力。

Wood has a memory. It remembers the forest. It remembers the tree.

Never underestimate the power of small, consistent steps toward a larger goal.

美好生活是一个过程，而不是一种状态。它是一个方向，而不是一个目的地。