[ULPIANUS libro secundo de officio consulis. ] §22.3.14.prCirca eum, qui se ex libertinitate ingenuum dicat, referendum est, quis actoris partibus fungatur.
[ULPIAN, in the second book on the Office of Consul.] Regarding a person who claims to be freeborn from a state of release from slavery, it must be considered who should perform the role of the plaintiff.
et si quidem in possessionem libertinitatis fuit, sine dubio ipsum oportebit ingenuitatis causam agere docereque se ingenuum esse: sin uero in possessione ingenuitatis sit et libertinus esse dicatur, scilicet eius qui ei controuersiam mouet, hoc probare debet qui eum dicit libertum suum: quid enim interest, seruum suum quis an libertum contendat? si quis autem fiducia ingenuitatis suae ultro in se suscipiat probationes ad hoc, ut sententiam ferat pro ingenuitate facientem, hoc est, ingenuum se esse ut pronuntietur, an obtemperare debeat, tractari potest.
And if indeed he was in the possession of the status of a freedman, without doubt he himself must bring the suit for free birth and show that he is freeborn. But if indeed he is in the possession of the status of free birth and is said to be a freedman—namely, of the person who raises the controversy against him—the one who claims him to be his freedman must prove this. For what difference does it make whether someone contends that a person is his slave or his freedman? However, if someone, through confidence in his free birth, voluntarily takes upon himself the burden of proof for this purpose, namely, that the judge may render a decision in favor of his free birth—that is, that he may be declared to be freeborn—it can be discussed whether one ought to comply with his wish.
et non ab re esse opinor morem ei geri probandi se ingenuum et sententiam secundum se dandam, cum nulla captio intercedat iuris.
And I think it is not unreasonable that his desire to prove himself freeborn be indulged, and that a judgment be given in his favor, since no legal disadvantage would intervene.