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

The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.

信念有创造的力量，也有毁灭的力量。

Whatever you fight, you strengthen, and whatyou resist, persists.

物种之间的边界比我们想象的更具渗透性。