The only limit to our realization of tomorrow is our doubts of today.

所有科学的起源在于渴望了解原因，而所有伪科学与欺骗的起源则在于宁愿接受虚假原因也不愿承认无知。

I don’t believe in an afterlife. This is it. Make the most of it.

To tax the larger incomes at a higher percentage than the smaller， is to lay a tax on industry and economy； to impose a penalty on people for having worked harder and saved more than their neighbors.

悲观者抱怨风向，乐观者期待风向改变，而领导者调整船帆。

当我们保护生物多样性时，我们就是在保护人类的安全网。