永远不要停止学习，因为世界永远不会停止变化。
Never stop learning, because the world never stops changing.
In our reasonings concerning matter of fact， there are all imaginable degrees of assurance， from the highest certainty to the lowest species of moral evidence.
自由的代价是永远保持警惕。
没有什么比一个没有什么可失去的人更危险的了。
"We do not write because we want to; we write because we have to."