"The trouble with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence."

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."

"I have lived in the world for an abominably long time."

"There is no logical impossibility in the hypothesis that the world was created five minutes ago, complete with all our memories and records."

"Of all the forms of caution, caution in love is perhaps the most fatal to true happiness."