Dig.1.1.9 Gaius 1 inst. Omnes populi, qui legibus et moribus reguntur, partim suo proprio, partim communi omnium hominum iure utuntur. (All peoples who are ruled by laws and long-standing custom partly use their own laws and partly the law that is common to all men)

Dig.1.1.10pr. Ulpianus 1 reg. Iustitia est constans et perpetua voluntas ius suum cuique tribuendi (Justice is the constant and perpetual will of giving everyone their Ius).

Dig.1.1.10.1 Ulpianus 1 reg. Iuris praecepta sunt haec: honeste vivere, alterum non laedere, suum cuique tribuere (The commands of law are these: to live honestly, to not injure <the rights> of others, and to give to each person his <Ius>).

Dig.1.1.10.2 Ulpianus 1 reg. Iuris prudentia est divinarum atque humanarum rerum notitia, iusti atque iniusti scientia. (Jurisprudence is the understanding of divine and human affairs, and the the skill of recognizing justice and injustice).