The test of our progress is not whether we add more to the abundance of those who have much; it is whether we provide enough for those who have too little.
地质学研究的真正魅力在于从已知到未知的思维锻炼。
The secret of happiness，you see，is not found in seeking more，but in developing the capacity to enjoy less.
The choice for mankind lies between freedom and happiness and for the great bulk of mankind, happiness is better.