Here is a list of interesting quotes I have encountered on Quotes of the Day and other places.

He may be mad, but there's method in his madness. There nearly always is method in madness. It's what drives men mad, being methodical. - GK Chesterton

No one means all he says, and yet very few say all they mean, for words are slippery and thought is viscous. - Henry Adams

All that is human must retrograde if it does not advance. - Edward Gibbon

If everything seems under control, you're not going fast enough - Mario Andretti

If a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts he shall end in certainties. - Sir Francis Bacon

There is no greater impotence in all the world like knowing you are right and that the wave of the world is wrong, yet the wave crashes upon you. - Norman Mailer

When I read about the evils of drinking, I gave up reading. - Henny Youngman

The test of courage comes when we are in the minority. The test of tolerance comes when we are in the majority. - Ralph W. Sockman

Try to learn something about everything and everything about something. - Thomas H. Huxley

You probably wouldn't worry about what people think of you if you could know how seldom they do. - Olin Miller

If wishes were fishes we'd all cast nets - Frank Herbert's Dune

Free advice is worth the price. - Robert Half