"Charity begins at home."

"Their silence is sufficient praise."

"There is nothing so easy but that it becomes difficult when you do it reluctantly."

"Too much liberty corrupts us all."

"What is done let us leave alone."

"Moderation in all things."

"Judge of a man by his questions rather than by his answers."

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

"There are two sides to every question."

"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."

"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."