 Justice is the steady and lasting willingness to give to others what they are entitled to (their right: jus [or ius] suum). Aquinas works with this Roman Law definition (ST II-II q. 58 a. 1c), and with Aristotle’s division of justice into (i) distributive (good judgment about how to divide up and parcel out beneficial or burdensome wholes or sets in a way that is fair because guided by appropriate criteria) and (ii) what Aquinas calls commutative justice (good judgment going far wider than Aristotle’s “corrective” justice, and concerned with all other kinds of dealings between persons). His prioritizing of the concept of right (jus), conceived as something that belongs to another, brings him to the brink of articulating a concept of human rights, a concept certainly implicit in his thesis that there are precepts of justice each imposing, on me and my communities, a duty to everyone without discrimination (indifferenter omnibus debitum: ST II-II q. 122 a. 6). For his definition of justice immediately entails that correlative to such duties of justice there must be rights that belong to everyone indifferenter. Many duties of justice are positive (affirmative duties to give, do, etc.), and Aquinas treats the duties of relieving poverty both under justice and under love (of neighbor, for God’s sake). The duties in either case are essentially the same, and Aquinas’ understanding of them strongly affects his understanding of justified private property rights, which are valid because needed for prosperity and development, but are subject to a duty to distribute, directly or indirectly, one’s superflua – that is, everything beyond what one needs to keep oneself and one’s family in the state of life appropriate to one’s (and their) vocation(s). For the natural resources of the world are “by nature” common; that is, reason’s principles do not identify anyone as having a prior claim to them other than under some customary or other socially posited scheme for division and appropriation of such resources, and such schemes could not be morally authoritative unless they acknowledged some such duty to distribute one’s superflua.