When a man sends you an impudent letter, sit right down and give it back to him with interest ten times compounded, and then throw both letters in the wastebasket.
Elbert HubbardIn the Life of Darwin by his son, there is related an incident of how the great naturalist once studied long as to just what a certain spore was. Finally he said, "It is this, for if it isn't, then what is it?" And all during his life he was never able to forget that he had been guilty of this unscientific attitude, for science is founded on certitude, not assumption.
Elbert Hubbard