Courage, it would seem, is nothing less than the power to overcome danger, misfortune, fear, injustice, while continuing to affirm inwardly that life with all its sorrows is good; that everything is meaningful even if in a sense beyond our understanding; and that there is always tomorrow.

The most destructive element in the human mind is fear. Fear creates aggressiveness; aggressiveness engenders hostility; hostility engenders fear, a disastrous circle.

Courage, it would seem, is nothing less than the power to overcome danger, misfortune, fear, injustice, while continuing to affirm inwardly that life with all its sorrows is good; that everything is meaningful even if in a sense beyond our understanding; and that there is always tomorrow.

It is not the fact of liberty but the way in which liberty is exercised that ultimately determines whether liberty itself survives.

Age is not measured by years. Nature does not equally distribute energy. Some people are born old and tired while others are going strong at seventy.

There is nothing to fear except the persistent refusal to find out the truth.

Inventive man has invented nothing -- nothing from scratch. If he has produced a machine that in motion overcomes the law of gravity, he learned the essentials from the observation of birds.