"This only is certain, that there is nothing certain; and nothing more miserable and yet more arrogant than man."

"No mortal man, moreover is wise at all moments."

"In these matters the only certainty is that nothing is certain."

"In comparing various authors with one another, I have discovered that some of the gravest and latest writers have transcribed, word for word, from former works, without making acknowledgment."

"The best plan is to profit by the folly of others."

"The only certainty is that nothing is certain."

"Did you exchange a walk-on part in a war, for a leading role in a cage?"

"There is one piece of advice, in a life of study, which I think no one will object to; and that is, every now and then to be completely idle - to do nothing at all."

"The line, often adopted by strong men in controversy, of justifying the means by the end."

"Whatever else may divide us, Europe is our common home; a common fate has linked us through the centuries, and it continues to link us today."

"The adventitious beauty of poetry may be felt in the greater delight with a verse given in a happy quotation than in the poem."

"When you have faults, do not fear to abandon them."