"There is a demand in these days for men who can make wrong appear right."

"That is true wisdom, to know how to alter one's mind when occasion demands it."

"What is done let us leave alone."

"Moderation in all things."

"I am a man, and whatever concerns humanity is of interest to me."

"Nothing is said that has not been said before."

"A wise man's question contains half the answer."

"A thinker sees his own actions as experiments and questions--as attempts to find out something. Success and failure are for him answers above all."

"The outcome of any serious research can only be to make two questions grow where only one grew before."

"Ask questions from your heart and you will be answered from the heart."

"In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted."

"The most erroneous stories are those we think we know best - and therefore never scrutinize or question."