No great achievement is possible without passion.
To be independent of public opinion is the first formal condition of achieving anything great or rational, whether in life or in science.
The true tragedies in life are not conflicts between right and wrong. They are conflicts between two rights.
No man is a hero to his valet. Not because the man is not a hero, but because the valet is a valet.
But what experience and history teach us is this: that peoples and governments never have learned anything from history, or acted on any lessons they might have drawn from it.
Every idea is a generalization, and generalization is the essence of thinking.