There's a dark side to everything.

True wisdom comes to each of us when we realize how little we understand about life, ourselves, and the world around us.

Everything should be made as simple as possible, but not simpler.

Not everything that counts can be counted, and not everything that can be counted counts.

Experience is a truer guide than the words of others.

Whoever despises the high wisdom of mathematics nourishes himself on delusion and will never still the sophistic sciences whose only product is an eternal uproar.