历史既没有愿望也没有能力使人变得更好或更坏；它仅仅记录了他们曾经是什么以及他们做了什么。
The battle of life is already half won by the young man who is brought personally in contact with high officials; and the great aim of every boy should be to do something beyond the sphere of his duties--something which attracts the attention of those who over him.
物理学的目的不是掌控自然，而是理解自然。
在计算学习的背景下，“可能近似正确”（PAC）学习的概念为理解学习算法的效率和可行性提供了一个框架。