The highest proof of the spirit is love. Love the eternal thing which can already on earth possess as it really is.

As soon as man does not take his existence for granted, but beholds it as something unfathomably mysterious, thought begins.

In case my life should end with the cannibals, I hope they will write on my tombstone, 'We have eaten Dr. Schweitzer. He was good to the end.'

A man is ethical only when life, as such, is sacred to him, that of plants and animals as that of his fellow men, and when he devotes himself helpfully to all life that is in need of help.

The stronger the reverence for natural life, the stronger grows also that for spiritual life.

The destiny of man is to be more and more human.

Your soul suffers if you live superficially.