AGNATION. - In Roman law, a. was the bond that united all free persons who were under the potestas of the same paterfamilias, or who would have been under it had he not died; that is, who were part of the same familia, or who would have been part of it had the common paterfamilias not died. This bond stood in contrast to cognation (corresponding to our consanguinity [v.] or kinship), which united all and only the persons descended from a single common ancestor. Therefore the bond of a., unlike cognation, ceased for the minor who left the family through emancipation, and for anyone who was adopted by another paterfamilias (but Justinian distinguished adoptio plena and adoptio minus plena, the second of which did not remove the adopted person from his family); on the other hand it also included, for example, those adopted by the paterfamilias, who were not however united by a bond of cognation with the other members of the family.
In Justinianic law the civil bond of a. (which was generally considered especially in relation to persons of the male sex) lost any legal importance, being replaced for all purposes by the natural bond of cognation.
Even the canonists, until the last century, used, in the same sense that they had in Roman law, the two terms a. and cognation. Pius Ciprotti