[POMPONIUS libro uicensimo secundo ad Sabinum. ] §12.6.19.prSi poenae causa eius cui debetur debitor liberatus est, naturalis obligatio manet et ideo solutum repeti non potest.
[POMPONIUS, On Sabinus, Book 22.] If a debtor has been released by way of penalty on the person to whom the debt is owed, a natural obligation remains, and therefore what has been paid cannot be recovered.
§12.6.19.1Quamuis debitum sibi quis recipiat, tamen si is qui dat non debitum dat, repetitio competit, ueluti si is qui heredem se uel bonorum possessorem falso existimans creditori hereditario soluerit: hic enim neque uerus heres liberatus erit et is quod dedit repetere poterit: quamuis enim debitum sibi quis recipiat, tamen si is qui dat non debitum dat, repetitio competit.
Although someone may receive a debt due to himself, nevertheless, if the person who gives it gives what is not due from him, an action for recovery is available; as, for example, if someone who falsely believes himself to be the heir or the possessor of the goods pays a creditor of the estate: for in this case neither will the true heir be released, and the payer will be able to recover what he gave: for although someone may receive a debt due to himself, nevertheless, if the person who gives it gives what is not due from him, an action for recovery is available.
§12.6.19.2Si falso existimans debere nummos soluero, qui pro parte alieni, pro parte mei fuerunt, eius summae partem dimidiam, non corporum condicam.
If, falsely believing that I owe them, I pay coins which belonged partly to another and partly to myself, I shall bring an action (condictio) for half of the sum, not for the physical coins themselves.
§12.6.19.3Si putem me Stichum aut Pamphilum debere, cum Stichum debeam, et Pamphilum soluam, repetam quasi indebitum solutum: nec enim pro eo quod debeo uideor id soluisse.
If I should think that I owe either Stichus or Pamphilus, whereas I actually owe Stichus, and I pay Pamphilus, I shall recover it as if what was not due had been paid; for I am not deemed to have paid this in discharge of what I actually owe.
§12.6.19.4Si duo rei, qui decem debebant, uiginti pariter soluerint, Celsus ait singulos quina repetituros, quia, cum decem deberent, uiginti soluissent, et quod amplius ambo soluerint, ambo repetere possunt.
If two co-debtors, who owed ten, have paid twenty equally, Celsus says that each will recover five, because, whereas they owed ten, they paid twenty, and what both have paid in excess, both can recover.