All changes follow a law.

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.

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

获得智慧是一种道德责任，它不仅仅是为了让你们的生活变得更加美好。有一个相关的道理非常重要，那就是你们必须坚持终身学习。如果不终身学习，你们将不会取得很高的成就。光靠已有的知识，你们在生活中走不了多远。