18. Juris praecepta sunt haec: honeste vivere, alterum non laedere, suum cuique tribuere.
D. 1. 1. 10. 1. Just. Inst. 1. 1. 3.
“These are the precepts of the law: to live honestly, to hurt no one, and to give to every man his own.” Attempts have been sometimes made to exhibit these three praecepta juris as based on a logical division of the sphere of legal obligation into three parts. This, however, is not the case. They are simply different modes of expressing the same thing, and each of them is wide enough to cover the whole field of legal duty. The third of them, indeed, is simply a variant of the received definition of justice itself: Justitia est constans et perpetua voluntas jus suum cuique tribuendi. D. 1. 1. 10 pr. Just. Inst. 1. 1. 1.