I'd rather be an optimist and a fool than a pessimist and right.

A pessimist is a well-informed optimist.

The government is merely a servant―merely a temporary servant; it cannot be its prerogative to determine what is right and what is wrong, and decide who is a patriot and who isn't. Its function is to obey orders, not originate them.

No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

You are neither right nor wrong because the crowd disagrees with you.

Success is the sole earthly judge of right and wrong.