Statistics: The only science that enables different experts using the same figures to draw different conclusions.
The dead might as well try to speak to the living as the old to the young.
The problem is never how to get new, innovative thoughts into your mind, but how to get old ones out. Every mind is a building filled with archaic furniture. Clean out a corner of your mind and creativity will instantly fill it.
Reveal not every secret you have to a friend, for how can you tell but that friend may hereafter become an enemy. And bring not all mischief you are able to upon an enemy, for he may one day become your friend.
Humor is the only test of gravity, and gravity of humor; for a subject which will not bear raillery is suspicious, and a jest which will not bear serious examination is false wit.
At the mention of the word mace, the guy looked scared and kind of melted back, though the crowd kept him moving forward.
The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'