Bertrand Russell

"The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts."

H. H. Williams

"Furious activity is no substitute for understanding."

George Orwell

"Every generation imagines itself to be more intelligent than the one that went before it, and wiser than the one that comes after it."

Isaac Asimov

"Never let your sense of morals get in the way of doing what's right."

Sir William Drummond

"He who will not reason is a bigot; he who cannot is a fool; and he who dares not is a slave."