“Children use the fist until they are of the age to use the brain”

“It is well for people who think to change their minds occasionally in order to keep them clean. For those who do not think, it is best to at least rearrange their prejudices once in a while”

“Less than fifteen percent of the people do any original thinking on any subject . . . The greatest torture in the world for most people is to think”

“If we would guide by the light of reason we must let our minds be bold”

“Better to be without logic than without feeling”

“I don't wait for moods. You accomplish nothing if you do that. Your mind must know it has got to get down to work”