Herbart, a famous scientist, has a famous saying: "When your throat is dry, you will have the spirit of swallowing the sea, which is faith;" When you are thirsty, you can only drink two glasses at most. This is science. " This sentence vividly points out the perceptual characteristics of faith and the rational characteristics of science. Faith is the spiritual pillar of man, and science is the material basis for man to transform the world. Material and spirit are two basic elements of human existence and development, so we should not only develop science, but also improve our lofty beliefs that match civilization. So the author David Lin wrote this far-reaching letter, rambling about science and faith.