The dog is a friend of man because it judges him not by his station.
I'm not perfect, but I'm trying every day to be better than I was yesterday.
PAC学习框架提供了一种形式化的方法来量化概念类的可学习性。
"The freedom to be yourself is a gift only you can give yourself. But once you do, no one can take it away."
"History remembers the names, but biography remembers the hearts."
自然的统一性不是我们发现的事实，而是我们对它提出的要求。
We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.