Natural Law

"True law is right reason in agreement with nature; it is of universal application, unchanging and everlasting; it summons to duty by its commands, and averts from wrongdoing by its prohibitions....It is a sin to try to alter this law, nor is it allowable to repeal any part of it, and it is impossible to abolish it entirely. We cannot be freed from its obligations by senate or people, and we need not look outside ourselves for an expounder or interpreter of it. There will not be different laws now and in the future, but one eternal and unchangeable law will be valid for all nations and all times, and there will be one master and ruler, that is God, over all, for he is the author of this law, its promulgator, and its enforcing judge. Whoever is disobedient is fleeing from himself and denying his human nature, and by reason of this very fact he will suffer the worst punishment" Cicero---
The Founding Fathers talked a lot about Natural Law (which I believe is the Spirit of Christ we are all born with essentially). I never heard it put into words quite so well as through Cicero.