Nothing truly valuable arises from ambition or from a mere sense of duty; it stems rather from love and devotion towards men and towards objective things.
However we select from nature a complex [of phenomena] using the criterion of simplicity, in no case will its theoretical treatment turn out to be forever appropriate (sufficient).... I do not doubt that the day will come when [general relativity], too, will have to yield to another one, for reasons which at present we do not yet surmise. I believe that this process of deepening theory has no limits.
The word 'God' is for me nothing more than the expression and product of human weaknesses, and religious scripture a collection of honourable, but still primitive legends which are nevertheless pretty childish. No interpretation, no matter how subtle, can (for me) change this.
One has a feeling that one has a kind of home in this timeless community of human beings that strive for truth. ... I have always believed that Jesus meant by the Kingdom of God the small group scattered all through time of intellectually and ethically valuable people.
Not until the creation and maintenance of decent conditions of life for all men are recognized and accepted as a common obligation of all men and all countries — not until then shall we, with a certain degree of justification, be able to speak of mankind as civilized.
Human beings can attain a worthy and harmonious life only if they are able to rid themselves, within the limits of human nature, of the striving for the wish fulfillment of material kinds. The goal is to raise the spiritual values of society.
That deep emotional conviction of the presence of a superior reasoning power, which is revealed in the incomprehensible universe, forms my idea of God.
My pacifism is an instinctive feeling, a feeling that possesses me because the murder of men is disgusting. My attitude is not derived from any intellectual theory but is based on my deepest antipathy to every kind of cruelty and hatred.