"Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful."

Fear of change stifles progress; understanding change directs it.

There are unknown forces in nature; when we give ourselves wholly to her, without reserve, she lends them to us; she shows us these forms, which our watching eyes do not see, which our intelligence does not understand or suspect.

发愤研究学问，常常忘记吃饭，一旦有所收获便又高兴地忘记了忧愁，连自己的渐趋衰老也没有感觉到。