动力学的方程在用变分法的语言表达时是完全的。

A man is the sum of his misfortunes. One day you'd think misfortune would get tired but then time is your misfortune.

Government, even in its best state, is but a necessary evil; in its worst state, an intolerable one.

The greatest glory in living lies not in never falling, but in rising every time we fall.

毁灭过往所有文明的原因在于财富和权力的不均分配倾向。

你不能通过人们如何度过他们的人生来评判他们。你只能通过他们如何对待你来评判。