The mere formulation of a problem is far more essential than its solution, which may be merely a matter of mathematical or experimental skills. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.

When the solution is simple, God is answering.

Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.

Intellectuals solve problems, geniuses prevent them.

It’s not that I’m so smart, it’s just that I stay with problems longer.

Small is the number of people who see with their eyes and think with their minds.

Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted.

He who joyfully marches to music in rank and file has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would suffice.