How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?
The pursuit of knowledge for its own sake, an almost fanatical love of justice and the desire for personal independence -- these are the features of the Jewish tradition which make me thank my stars that I belong to it.
...Intelligence and character of the masses are incomparably lower than the intelligence and character of the few who produce something valuable for the community.
Concepts which have proved useful for ordering things easily assume so great an authority over us, that we forget their terrestrial origin and accept them as unalterable facts. They then become labeled as 'conceptual necessities,' etc. The road of scientific progress is frequently blocked for long periods by such errors.