Kill one man, and you are murderer.

Kill one man and you're a murderer, kill a million and you're a conqueror.

It is sometimes important for science to know how to forget the things she is surest of.

Nothing leads the scientist so astray as a premature truth.

There are moments when very little truth would be enough to shape opinion. One might be hated at extremely low cost.

Never feel remorse for what you have thought about your wife; she has thought much worse things about you.

When I was young I pitied the old. Now old, it is the young I pity.