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

I'm not bossy. I'm the boss.

——1941年与美国外交官阿弗雷尔·哈里曼（Averell Harriman）的谈话

The fear of death follows from the fear of life. A man who lives fully is prepared to die at any time.

文明是人类与其环境互动的结果。