Mathematics is not a spectator sport. You have to get involved.
人生中唯一真正的失败是不忠于自己所知的最好。
The facility which this revenue gives for borrowing money is what has enabled the greater part of Europe to accumulate a capital of such a magnitude.
思考的过程不仅仅是把一件事加到另一件事上;它在于观察结构特征和结构要求的操作。