"Charity begins at home."

"Their silence is sufficient praise."

"Moderation in all things."

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

"I bid him look into the lives of men as though into a mirror, and from others to take an example for himself."

"You believe that easily which you hope for earnestly."

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

"If you ask too many questions, you will find no answers, only more questions."

"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."

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