No man's knowledge here can go beyond his experience.

Positive thinking will let you do everything better than negative thinking will.

The first step towards knowledge is to know that we are ignorant.

Risk comes from not knowing what you're doing.

Fortune favors the prepared mind.

It is one of my sources of happiness never to desire a knowledge of other people's business.

Real knowledge is to know the extent of one's ignorance.

Knowledge is the eye of desire and can become the pilot of the soul.

Life is given to us, we earn it by giving it.

Our knowledge can only be finite, while our ignorance must necessarily be infinite.