As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

There is, however, a somber point in the social outlook of Americans. Their sense of equality and human dignity is mainly limited to people of white skin.... The more I feel like an American, the more the situation pains me.

Not all that counts, can be counted

Without creative, independently thinking and judging personalities the upward development of society is as unthinkable as the development of the individual personality without the nourishing soil of the community.

The devil has put a penalty on all things we enjoy in life. Either we suffer in our health, or we suffer in our soul, or we get fat.

The difference between stupidity and genius is that genius has its limits.

Only in mathematics and physics was I, through self-study, far beyond the school curriculum, and also with regard to philosophy as it was taught in the school curriculum.