数学的本质在于它的自由。
质量是企业的生命线。
做正确的事，而不是容易的事。
The natural effort of every individual to better his own condition， when suffered to exert itself with freedom and security， is so powerful a principle that it is alone， and without any assistance， not only capable of carrying on the society to wealth and prosperity but of surmounting a hundred impertinent obstructions with which the folly of human laws too often encumbers its operations.
The purpose of psychology is to explain how we manage to live.