Only the [Catholic] Church stood squarely across the path of Hitler’s campaign for suppressing truth. I never had any special interest in the Church before, but now I feel a great affection and admiration because the Church alone has had the courage and persistence to stand for intellectual truth and moral freedom. I am forced thus to confess that what I once despised I now praise unreservedly.

This is what the painter, the poet, the speculative philosopher, and the natural scientists do, each in his own fashion.

Development of Western science is based on two great achievements: the invention of the formal logical system (in Euclidean geometry) by the Greek philosophers, and the discovery of the possibility to find out causal relationships by systematic experiment (during the Renaissance). In my opinion, one has not to be astonished that the Chinese sages have not made these steps. The astonishing thing is that these discoveries were made at all.

If people are good because they fear punishment, and hope for reward, then we are a sorry lot indeed.

It is my fate to be considered an authority, since I spent my youth rebelling against it.

I am satisfied with the mystery of life's eternity and with a knowledge, a sense, of the marvelous structure of existence - as well as the humble attempt to understand even a tiny portion of the Reason that manifests itself in nature.

Today we must abandon competition and secure cooperation. This must be the central fact in all our considerations of international affairs; otherwise we face certain disaster. Past thinking and methods did not prevent world wars. Future thinking must prevent wars...The stakes are immense, the task colossal the time is short. But we may hope- we must hope- that man's own creation, man's own genius, will not destroy him.