If a man does not strike first, he will be the first struck

He who dares wins!
Originally the motto of the British Special Air Service and spread to many military units worldwide.

Stärke liegt nicht in der Verteidigung, sondern in Angriff. Only if this wasn't told by Hitler, this could have been a great chess quote.
- Athenagoras of Syracuse
I think the above quote sums up the nature of chess almost perfectly.
Do you guys know any other quotes you think do the same?