What the individual can do is to give a fine example, and to have the courage to uphold ethical values .. in a society of cynics.

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.

Earnestly I must exert myself in order to return as much as I have received.

What physics looks for: The simplest possible system of thought which will bind together the observed facts.

What separates me from most so-called atheists is a feeling of utter humility toward the unattainable secrets of the harmony of the cosmos.

All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.

Great spirits often meet violent oppisition with mediocre minds.