You have to be willing to make mistakes; the big thing is to not make the same mistake over and over again.
A method of solution is perfect if we can foresee from the start, and even prove, that following that method we shall attain our aim.
无论一个人被认为多么自私,他的本性中显然存在某些原则,这些原则使他对别人的命运感兴趣,并将他们的幸福视为自己的必要,尽管他从中除了看到它时的快乐外一无所得。
Character is much easier kept than recovered.