“Familiae” appellatio qualiter accipiatur, videamus. et quidem varie accepta est. nam et in res et in personas diducitur; in res, ut puta in lege duodecim tabularum his verbis: “adgnatus proximus familiam habeto”. ad personas autem refertur familiae significatio ita, cum de patrono et liberto loquitur lex: “ex ea familia,” inquit, “in eam familiam”; et hic de singularibus personis legem loqui constat. familiae appellatio refertur et ad corporis cuiusdam significationem, quod aut iure proprio ipsorum aut communi universae cognationis continetur. iure proprio familiam dicimus plures personas, quae sunt sub unius potestate aut natura aut iure subiectae, ut puta patrem familias, matrem familias, filium familias, filiam familias quique deinceps vicem eorum sequuntur, ut puta nepotes et neptes et deinceps. pater autem familias appellatur, qui in domo dominium habet, recteque hoc nomine appellatur, quamvis filium non habeat: non enim solam personam eius, sed et ius demonstramus: denique et pupillum patrem familias appellamus. et cum pater familias moritur, quotquot capita ei subiecta fuerint, singulas familias incipiunt habere: singuli enim patrum familiarum nomen subeunt. idemque eveniet in eo, qui emancipatus est, nam et hic sui iuris effectus propriam familiam habet. communi iure familiam dicimus omnium adgnatorum: nam etsi patre familias mortuo singuli singulas familias habent, tamen omnes, qui sub unius potestate fuerunt, recte eiusdem familiae appellabuntur, qui ex eadem domo et gente proditi sunt. servitutium quoque solemus appellare familias, ut in edicto praetoris ostendimus sub titulo de furtis, ubi praetor loquitur de familia publicanorum. sed ibi non omnes servi, sed corpus quoddam servorum demonstratur, huius rei causa paratum, hoc est, vectigalis causa. alia autem parte edicti omnes servi continentur, ut de hominibus coactis, et vi bonorum raptorum; item redhibitoria, si deterior res reddatur emptoris opera, aut familiae eius, et interdicto “unde vi” familiae appellatio omnes servos comprehendit; sed et filii continentur. item appellatur familia plurium personarum, quae ab eiusdem ultimi genitoris sanguine proficiscuntur (sicuti dicimus familiam Iuliam), quasi a fonte quodam memoriae. mulier autem familiae suae et caput et finis est.
(Ulpian, Dig. 50.16.195)
Let us see how the term familia is to be understood. It has various meanings, for it is applied both to property and to persons. To property: as, for example, in a law of the Twelve Tables in these words: ‘Let the nearest agnate have the familia.’ It has the meaning applying to persons when, e.g., a law says of patron and freedman ‘from that familia‘, ‘into that familia‘ and here it is understood that the law speaks of particular persons.
The term ‘familia‘ is also used to mean a certain body of persons, defined either by a strict legal bond between the persons themselves or in a general sense of people joined by a looser relationship of kinship.
In the strict legal sense we call a familia a number of people who are by birth or by law subjected to the potestas (power) of one man, e.g. paterfamilias (father of a familia), mater (mother of a familia), son or daughter of a familia, and so on in succession, e.g. grandsons, granddaughters, etc. Paterfamilias (head of a household) is the title given to the person who holds sway in the house, and he is correctly so called even if he has no children, for we are designating not only him as a person, but his legal right: indeed, we call even a minor paterfamilias. When a paterfamilias dies, all the persons subject to him begin each to have a separate familia; for each individual takes on the title paterfamilias. The same will happen when someone is emancipated, for he becomes sui iuris (legally independent) and begins to have his own familia.
In the wider sense we use familia legally of all agnates: for even though on the death of the paterfamilias each one has a separate familia, all the same all those who were under the power of one man will correctly be said to belong to the same familia, since they issued from the same gens (kin group) and the same house.
We also habitually use familia of slaves, e.g. in the praetorian edict under the heading ‘on theft’, where the praetor talks about the familia of tax-farmers. In that passage, not all slaves are meant, but a particular body of slaves got together for that purpose, that is, for tax-collecting. Elsewhere in the edict, however, it is used of all slaves, e.g., in the section ‘On armed assemblage and robbery by force’, or again in ‘Action for recovery’: ‘should the condition of the goods be impaired by the activity of the buyer or his familia‘.
In the interdict ‘On violence’, the term familia includes all the slaves, and sons as well.
Again, familia is used of several persons who all descend by blood from a single remembered source (e.g., we speak of the Julian family). A woman, however, is both the beginning and end of her own familia. (tr. Jane F. Gardner & Thomas Wiedemann)