CASE 5: Sui Iuris and Alieni Iuris

Gaius, Institutiones 1.48, 52, 55 (= D. 1.6.1 pr.-1; 1.6.3)

(48) Sequitur de iure personarum alia divisio.

potestate nostra sunt liberi nostri, quos iustis nuptiis procreavimus. quod ius pro­prium civium Romanorum est. fere enim nulli alii sunt homines, qui talem in filios suos habent potestatem, qualem nos habemus, idque divus Hadrianus edicto, quod proposuit de his, qui sibi liberisque suis ab eo civitatem Romanam petebant, significavit.

(48) There follows another distinction in the law of personal status: some per­sons are sui iuris, some are subjected to another’s legal right (alieno iuri)....

(52) So, slaves are in the power (in potestate) of their owners. This power comes from the law of nations; for uniformly among all peoples we can observe that owners have the power of life and death over their slaves, and whatever is acquired through a slave is acquired for the owner... .

(55) Likewise in our power (in potestate nostra) are our children whom we have sired in a legitimate marriage.

1.      When the Old Man Dies. “And when the pater familias dies, all the individu­als who were subject to him start to have their own households; for they each assume the status of pater familias.” So says Ulpian in Case 4, but not quite correctly. Suppose, for instance, that a pater familias dies and leaves behind only a son and a daughter; the son then becomes a pater familias even though he does not have any children (and may not even be old enough to procreate), and the daughter also becomes head of her own familia. But because she can have no agnatic descendants of her own (be sure you understand why; see Case 3), she is, as Ulpian puts it in section 5 of Case 4, “both the beginning and the end of her familia,” in the sense that her independent household will die with her. This general situation would be unaffected if either the son or the daughter were married with children prior to their fathers decease, nor would it matter if either one was no longer resident in the fathers home. But what if, for instance, the son had married, had children, and then prede­ceased his father? His children (unlike those of his sister) would remain in the household of his pater familias; and even if they were still infants when their grandfather died, each of them would begin to have a separate household. That is to say, as a general rule, upon the death of a paterfamilias, all the free persons who were directly in his power, without any surviving intermediary, at once became heads of their own households.

2.      Sui Iuris. A person who is head of a household, whether male or female, is de­scribed in Roman law as sui iuris, that is, “under his own legal power.” Sui iuris persons are, in principle, the only completely free individuals in Roman pri­vate law. Some of them may, however, be unable to function fully because of their youth or mental incapacity; for these persons there are various kinds of guardians (see Chapter VA). All other free persons are “subjected to another's legal right (alieno iuri)”; they are usually referred to as alieni iuris, “under an­other's power,” although this is not a technical term.

3.      Back to the Real World. In this chapter, particularly in Cases 4 and 5, many strange concepts are introduced within a fairly brief space of time. Don't worry if it doesn't all make sense at first. What is important is to absorb a basic idea of the very different legal framework within which Roman family law was conceived, even if this framework seems, at first, simply impossible to believe. As anthropologists have shown, household structures are in fact extremely malleable; and the Roman one endured, with only limited modifi­cations, for more than a millennium. Nevertheless, as you will also have oc­casion to observe in the following chapters, many of the differences between the Roman household and our own are more matters of legal emphasis than of substance. This Case, for instance, appears to draw a direct comparison be­tween slaves and children-in-power. But free children are not slaves (that would violate the fundamental principle of Case 2), and in many respects ac­tual Roman family life does not appear to depart profoundly from the behav­ioral norm for premodern societies (see Chapter III). Correspondingly, the peculiar fact that in Roman law a wife does not join the household of her hus­band but remains in that of her pater familias does not undermine the consid­erable importance of marriage as a Roman social institution (see Chapter II).