"Man has lost the capacity to foresee and to forestall. He will end by destroying the earth."

"Constant kindness can accomplish much. As the sun makes ice melt, kindness causes misunderstanding, mistrust, and hostility to evaporate."

"The greatest good is to do good to others."

"The human race is a race of slaves, and it will remain so until it learns to think for itself."

"The greatest discovery of all time is that a person can change his future by merely changing his attitude."