All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

Knowledge is power. Information is liberating. Education is the premise of progress, in every society, in every family.

Education is the passport to the future, for tomorrow belongs to those who prepare for it today.

Never, never, never give up.

Knowledge is knowing that we cannot know.

Experience without theory is blind, but theory without experience is mere intellectual play.

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

Be miserable. Or motivate yourself. Whatever has to be done, it's always your choice.

Optimism is the faith that leads to achievement. Nothing can be done without hope and confidence.

Strong and bitter words indicate a weak cause.