在数学中，真理总是相对于你所在的系统而言的。
The minimum content of natural law is necessary for any legal system.
Books say: She did this because. Life says: She did this. Books are where things are explained to you; life is where things aren't.
The camera is like a weapon; it's dangerous if you don't know how to use it.
The theory of probabilities is at bottom nothing but common sense reduced to calculus.