Courage isn't the absence of fear, but the will to keep going.
The person who tries to live alone will not succeed as a human being. His heart withers if it does not answer another heart. His mind shrinks away if he hears only the echoes of his own thoughts and finds no other inspiration.
阅读不是为了反驳和辩驳,也不是为了盲目相信和理所当然,也不是为了找话题和谈资,而是为了权衡和思考。
To every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.
A good mathematician is one who can see analogies between theorems; a great mathematician is one who can see analogies between analogies.