Only the Catholic Church protested against the Hitlerian onslaught on liberty. Up till then I had not been interested in the Church, but today I feel a great admiration for the Church, which alone has had the courage to struggle for spiritual truth and moral liberty

It is difficult to say what truth is, but sometimes it is so easy to recognize a falsehood.

The mathematician knows some things, no doubt, but not those things one usually wants to get from him.

My scientific work is motivated by an irresistible longing to understand the secrets of nature and by no other feeling. My love for justice and striving to contribute towards the improvement of human conditions are quite independent from my scientific interests.

While I am a convinced pacifist there are circumstances in which I believe the use of force is appropriate - namely, in the face of an enemy unconditionally bent on destroying me and my people.

The best that Gauss has given us was likewise an exclusive production. If he had not created his geometry of surfaces, which served Riemann as a basis, it is scarcely conceivable that anyone else would have discovered it. I do not hesitate to confess that to a certain extent a similar pleasure may be found by absorbing ourselves in questions of pure geometry.

The heart says yes, but the mind says no.