导言政府在与个人签订契约时,为了这个契约而放弃自己的宪法权力,其角色便从立法者变成了道德代理人,具有与个人相同的权利义务。或许可以合理地认为,政府的立法权是不包含其承诺的,除非为了承诺而行使之。从理论上来说,遵守承诺的理念,与制定能够改变承诺之效力的法律的权力,是不可能相互协调的。①亚历山大·汉密尔顿曾就公共信用问题给美国参议院写过一封信, Introduction When the government contracted with an individual, giving up his constitutional power for the contract, the government changed its role from a legislator to a moral agent with the same rights and obligations as an individual. It may be reasonable to assume that the government’s legislative power does not include its promises, unless it is exercised for the promise. In theory, it is impossible to reconcile the concept of commitment with the power of the law that can change the validity of a commitment. ① Alexander Hamilton wrote a letter to the U.S. Senate on public credit issues,