man is the only animal which causes pain to others with no other object than causing pain…No animal ever torments another for the sake of tormenting:… - Arthur Schopenhauer

Sleep is the interest we have to pay on the capital which is called in at death; and the higher the rate of interest and the more regularly it is paid, the further the date of redemption is postponed.

If children were brought into the world by an act of pure reason alone, would the human race continue to exist? Would not a man rather have so much sympathy with the coming generation as to spare it the burden of existence, or at any rate not take it upon himself to impose that burden upon it in cold blood?

It may sometimes happen that a truth, an insight, which you have slowly and laboriously puzzled out by thinking for yourself could have easily have been found already written in a book: but it is a hundred times more valuable if you have arrived at it by thinking for yourself. For only then will it enter your thought system as an integral part and living member, be perfectly and firmly consistent with it and in accord with all its other consequences and conclusions, bear the hue, colour and stamp of your whole manner of thinking, and have arrived at just the moment it was needed ; thus it will stay firmly and forever lodged in your mind.