That which costs little is less valued.

No matter how thin you slice it, there will always be two sides.

Let us try to teach generosity and altruism, because we are born selfish.

Don't send me flowers when I'm dead. If you like me, send them while I'm alive.

A scientific man ought to have no wishes, no affections, - a mere heart of stone.

Be like a tree and let the dead leaves drop.

I can bear any pain as long as it has meaning.

An intense anticipation itself transforms possibility into reality; our desires being often but precursors of the things which we are capable of performing.

Enthusiasm... the sustaining power of all great action.

An original idea. That can't be too hard. The library must be full of them.

Tell me thy company, and I shall tell thee what thou art.

I sound my barbaric yawp over the rooftops of the world.

I've learned that you shouldn't go through life with a catcher's mitt on both hands; you need to be able to throw something back.

Never accept a drink from a urologist.

A good traveller has no fixed plans, and is not intent on arriving.

A person preaches well that lives well.

I must not write a word to you about politics, because you are a woman.

He who never made a mistake, never made a discovery.

A good liar must have a good memory.

I have noticed that nothing I have never said ever did me any harm.

All battles are fought by scared men who'd rather be some place else.