To live is the rarest thing in the world. Most people exist, that is all.

Let the guarantee of free speech be in every man's determination to use it, and we shall have no need of paper declarations.

Life does not need to mutilate itself in order to be pure.

If people do not believe that mathematics is simple, it is only because they do not realize how complicated life is.

Humility is really important because it keeps you fresh and new.

As you go through life, you've got to see the valleys as well as the peaks.

I am an American; free born and free bred, where I acknowledge no man as my superior, except for his own worth, or as my inferior, except for his own demerit.

The more sand that has escaped from the hourglass of our life, the clearer we should see through it.

Life can only be understood backwards; but it must be lived forwards.

If one's different, one's bound to be lonely.

Open your arms to change, but don't let go of your values.

The rich will do anything for the poor but get off their backs.

The 'good old times'-all times, when old, are good.

Science is the outcome of being prepared to live without certainty and therefore a mark of maturity. It embraces doubt and loose ends.

The love of life is necessary to the vigorous prosecution of any undertaking.

History has shown there are no invincible armies.

He who has a why to live can bear with almost any how.

The universe we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but blind, pitiless indifference

There is one common struggle against those who have appropriated the earth, the money, and the machines.

The present is theirs; the future, for which I really worked, is mine.

A mother takes twenty years to make a man of her boy, and another woman makes a fool of him in twenty minutes.