The most considerable difference I can see between men and animals is not in reason, but in the extent of the power of using it.  
幸福并不容易。很难在我们内心找到它,更不可能在别处找到它。
Wealth is the product of man's capacity to think.
每一个挑战都是学习和改进的机会。
真相往往令人不适,但必不可少。