"The only way to make sense of change is to plunge into it, move with it, and join the dance."

"To be happy, one must be free."

"I tore myself away from the safe comfort of certainties through my love for truth - and truth was undoubtedly the highest mistress I ever served."

"Old age is a parody of life."

"I know of no other experience more thrilling than to be at the heart of a debate, to be part of the current of ideas."