"It is impossible for someone to dispel his fears about the most important matters if he does not understand the nature of the universe but still gives some credence to myths. So that without the study…"

"It is not the man who has too little, but the man who craves more, that is poor."

"The time when we are best able to enjoy ourselves is when we have least need of enjoyment."

"We must not violate nature, but obey her."

"The quantity of pleasure is to be judged by the quantity of pain it removes."