那些疯狂到认为自己能改变世界的人,往往真的改变了世界。
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.