There are two tragedies in life. One is to lose your heart's desire. The other is to gain it.
A life spent making mistakes is not only more honourable, but more useful than a life spent doing nothing.
Progress is impossible without change, and those who cannot change their minds cannot change anything.
No man who is occupied in doing a very difficult thing, and doing it very well, ever loses his self-respect.
Success does not consist in never making mistakes but in never making the same one a second time.
Marriage is an alliance entered into by a man who can't sleep with the window shut, and a woman who can't sleep with the window open.