Problems cannot be solved by thinking within the framework in which the problems were created.

It is best, it seems to me, to separate one's inner striving from one's trade as far as possible. It is not good when one's daily break is tied to God's special blessing.

I never think of the future. It comes soon enough. When visiting the U.S. from Germany for a winter academic stay.

No idea is conceived in our mind independent of our five senses [i.e., no idea is divinely inspired].

When I was still a rather precocious young man, I already realized most vividly the futility of the hopes and aspirations that most men pursue throughout their lives.

I have no particular talent. I am merely inquisitive.

Example isn't another way to teach, it is the only way to teach.