I have tried to avoid long numerical computations, thereby following Riemann's postulate that proofs should be given through ideas and not voluminous computations.

Some people have got a mental horizon of radius zero and call it their point of view.

No other question has ever moved so profoundly the spirit of man; no other idea has so fruitfully stimulated his intellect; yet no other concept stands in greater need of clarification than that of the infinite.

The art of doing mathematics consists in finding that special case which contains all the germs of generality.

Mathematics knows no races or geographic boundaries; for mathematics, the cultural world is one country.

He who seeks for methods without having a definite problem in mind seeks in the most part in vain.

However unapproachable these problems may seem to us and however helpless we stand before them, we have, nevertheless, the firm conviction that their solution must follow by a finite number of purely logical processes.