"To be a writer is to sit down at one's desk in the chill portion of every day, and to write; not waiting for the little jet of the blue flame of genius to start from the breastbone--just writing."

The state of nature has a law of nature to govern it, which obliges every one: and reason, which is that law, teaches all mankind, who will but consult it, that being all equal and independent, no one ought to harm another in his life, health, liberty, or possessions.

写文章的方法，贵在自己有所心得。

数学的本质在于它的自由。