The greatest happiness is to know the source of unhappiness.
We are all bound by the social contract to obey the laws, but we also have the right to participate in making those laws.
The best fertilizer is a farmer's knowledge mixed with nature's wisdom.
I am now physically incapable of doing any of the things I used to enjoy, but I don’t miss them.
善于学习的人,能够透彻地知道事情的道理;善于实践的人,能够把事情疑难之处弄清楚。