Every human life involves an unfathomable mystery, for man is the riddle of the universe, and the riddle of man in his endowment with personal capacities.

Some things mankind can finish and be done with, but not ... science, that persists, and changes from ancient Chaldeans studying the stars to a new telescope with a 200-inch reflector and beyond; not religion, that persists, and changes from old credulities and world views to new thoughts of God and larger apprehensions of his meaning.

Life asks not merely what you can do; it asks how much can you endure and not be spoiled.

It is magnificent to grow old, if one keeps young.

Democracy is based upon the conviction that there are extraordinary possibilities in ordinary people.

Don't simply retire from something; have something to retire to.

Hating people is like burning down your own house to get rid of a rat.