1. The essence of mathematics lies in its freedom. —— Kang Muer

2. Mathematics has made an important contribution to the observation of nature. It explains the simple primitive elements in the regular structure, and the celestial bodies are built with these primitive elements. —— Kepler

3. Mathematical methods penetrate and dominate all theoretical branches of natural science. It has increasingly become the primary measure of scientific achievement. ——Von Neumann

4. Mathematicians are essentially obsessed. Without obsession, there would be no mathematics. —— Nuvales

5. When mathematicians derive equations and formulas, they get full happiness just like seeing statues, beautiful scenery, hearing beautiful tunes, etc. ——Kopnin

6. No question can touch people's emotions as deeply as infinity. There are few other concepts that can stimulate the mind to produce fruitful thoughts like infinity. However, there is no Other concepts can be as demanding of elucidation as infinity. ——Hilbert

7. Mathematics is the key to opening the door to science. ——Bacon

8. Mathematics is symbols plus logic. ——Russell

9. Mathematics is a variety of proof techniques.

—— Wittgenstein