因果关系的阶梯有三个梯级:观察、行动和想象。
The ladder of causation has three rungs: seeing, doing, and imagining.
I'm the reason you're fed, I'm the reason you're led.
One should always play fairly when one has the winning cards.
任何认真从事任何科学工作的人都会意识到,在科学殿堂的大门上方写着这样的文字:你必须有信仰。