Gaius, Institutes, Book I. All nations who are ruled by law and customs make use partly of their own law, and partly of that which is common to all men. For whatever law any people has established for itself is peculiar to that State, and is called the Civil Law, as being the particular law of that State. But whatever natural reason has established among all men is equally observed by all mankind, and is called the Law of Nations, because it is the law which all nations employ.

Gaius, Institutes, Book I. All the law which We make use of relates either to persons, things, or actions.

Gaius, Institutes, Book I. The principal division of the law of persons is as follows, namely, that all men are either free or slaves.

Gaius, Institutes, Book I. Freedmen are those who are manumitted from lawful slavery.

Gaius, Institutes, Book I. Another division of persons follows according to law, some of whom are their own masters, and some are subject to the control of others. We shall now consider those who are subject to the control of others; for if we know who these persons are, we shall at once understand who those are that are their own masters. Let us then examine those who are under the control of others. 1Thus, slaves are under the power of their masters, and this power is derived from the Law of Nations, for we may perceive that among nearly all nations masters have the power of life and death over their slaves, and whatever is acquired by a slave is acquired by his master. 2But, at present, it is not permitted to any persons living under Roman dominion to be guilty of cruelty to their slaves which is atrocious, or without a cause recognized by the law. For, according to a Constitution of the Divine Antoninus, anyone who kills his slave without a cause shall be punished as severely as one who kills the slave of another; the inordinate severity of masters is also repressed by a Constitution of the same Emperor.

Gaius, Institutes, Book I. Our children also who are born in lawful marriage are under our control; which is a law peculiar to Roman citizens.

Gaius, Institutes, Book I. Adoption, generally speaking, takes place in two ways, either by the authority of the Emperor, or by the order of a magistrate. We adopt those by the authority of the Emperor who are their own masters; and this kind of adoption is called arrogation, because he who adopts is asked, that is, interrogated, whether he is willing that the party whom he is about to adopt shall be his lawful son; and he who is adopted is asked whether he suffers this to be done, We adopt by the order of a magistrate those who are under paternal control, whether they are in the first degree of children, such as son and daughter, or in one that is more remote, as grandson and granddaughter, and great-grandson and great-granddaughter. 1There is one thing common to both kinds of adoption, namely, that those who are incapable of procreation, as for instance, eunuchs, can adopt. 2Adoption effected through the Emperor is peculiar in that if anyone who has children under his control gives himself in arrogation, he himself is not only subjected to the authority of his adoptive father, but also his children and grandchildren pass under the control of the former.

Gaius, Institutes, Book I. He who has a son and a grandson under his control is at perfect liberty to release his son from his authority, and to retain it over his grandson; or, on the other hand, to retain his son under his control and to manumit his grandson; or to make both of them their own masters. We hold that the same rule applies to a great-grandson.

Gaius, Institutes, Book I. Those are agnates who are connected by relationship to persons of the male sex, just as cognates on the father’s side; as, for instance, a brother begotten by the same father, the son of a brother, or a grandson sprung from the latter; and, in like manner, a paternal uncle, the son of the latter, or a grandson descended from him.