Mathematics is concerned only with the enumeration and comparison of relations.

There have been only three epoch-making mathematicians, Archimedes, Newton, and Eisenstein.

I have had my results for a long time: but I do not yet know how I am to arrive at them.

Finally, two days ago, I succeeded - not on account of my hard efforts, but by the grace of the Lord. Like a sudden flash of lightning, the riddle was solved. I am unable to say what was the conducting thread that connected what I previously knew with what made my success possible.

To the distracting occupations belong especially my lecture courses which I am holding this winter for the first time, and which now cost much more of my time than I like. Meanwhile I hope that the second time this expenditure of time will be much less, otherwise I would never be able to reconcile myself to it, even practical (astronomical) work must give far more satisfaction than if one brings up to B a couple more mediocre heads which otherwise would have stopped at A.

Mathematicians stand on each other's shoulders.

In mathematics there are no true controversies.