“A pessimist is a man who thinks everybody is as nasty as himself, and hates them for it.”

Progress is impossible without change, and those who cannot change their minds cannot change anything.

You see things; and you say, 'Why?' But I dream things that never were; and I say, 'Why not?'

You see things; you say, 'Why?' But I dream things that never were; and I say, 'Why not?'

There are two tragedies in life. One is to lose your heart's desire. The other is to gain it.

He who can, does. He who cannot, teaches.

Beware of false knowledge; it is more dangerous than ignorance.