AGNATE (Lat. agnatus). Agnates, in the law both of England and Scotland, are per sons related through the father, as cognates are persons related through the mother. In the Roman law, both of these terms had a somewhat different signification. Agnates, by that system, were persons related through males only, whilst cognates were all those in whose connection, though on the father's side, one or more female links intervened. Thus, a brother's son was his uncle's A., because the propinquity was wholly by males; a sister's son was his cognate, because a female was interposed in that relationship. With us the intervention of females is immaterial, provided the connection be on the male, or paternal side of the house. The cause of our having thus changed the meaning of terms mani festly borrowed from the Roman law, seems to be that in Home the distinction between and cognates was founded on an institution which has not been adopted in the Roman sense by any modern nation—that, namely, of the patria potestas (q.v.). Roman agnati are defined by Hugo to be all those who either were actually under the same pater familias, or would have been so had he been alive; and thus it was that, as no one could belong to two different families at the same time, the agnation to the original family was destroyed, and a new agnation created, not only by marriage, but by adoption (q. v.).
The foundation of cognation, again, was a legal marriage. All who could trace up their origin to the same marriage were cognati; and thus the term cognatus, generally speaking, comprehended agnatus. But though an agnatus was thus almost always a cognatus, a cognatus was an agnatus only when his relationship by blood was traceable through males. Justinian abolished entirely the distinction between agnates and cognates, and admitted both to legal succession and to the office of tutor of law, not only kinsmen by the father, though a female had been interposed, but even those by the mother (Nov.118, c. 4, 5). As to the legal effects of the distinction in the modern sense, see SUCCESSION, GUARDIAN.