[AFRICANUS libro octauo quaestionum. ] §19.5.24.prTitius Sempronio triginta dedit pactique sunt, ut ex reditu eius pecuniae tributum, quod Titius pendere deberet, Sempronius praestaret computatis usuris semissibus, quantoque minus tributorum nomine praestitum foret, quam earum usurarum quantitas esset, ut id Titio restitueret, quod amplius praestitum esset, id ex sorte decederet, aut, si sortem et usuras summa tributorum excessisset, id quod amplius esset Titius Sempronio praestaret: neque de ea re ulla stipulatio interposita est.
[AFRICANUS, in the eighth book of Questions.] Titius gave Sempronius thirty, and they agreed that Sempronius should pay the tax which Titius was obliged to pay out of the return on that money, calculating interest at six percent, and that he should restore to Titius whatever less was paid under the head of taxes than the amount of that interest; and that whatever was paid in excess should be deducted from the principal, or, if the total of the taxes exceeded both principal and interest, Titius should pay the excess to Sempronius. No stipulation was entered into regarding this matter.
Titius consulebat, id quod amplius ex usuris Sempronius redegisset, quam tributorum nomine praestitisset, qua actione ab eo consequi possit.
Titius consulted as to which action he could use to obtain from Sempronius what the latter had collected from interest in excess of what he had paid under the head of taxes.
respondit pecuniae quidem creditae usuras nisi in stipulationem deductas non deberi: uerum in proposito uidendum, ne non tam faenerata pecunia intellegi debeat, quam quasi mandatum inter eos contractum, nisi quod ultra semissem consecuturus esset: sed ne ipsius quidem sortis petitionem pecuniae creditae fuisse, quando, si Sempronius eam pecuniam sine dolo malo uel amisisset uel uacuam habuisset, dicendum nihil eum eo nomine praestare debuisse.
He answered that indeed the interest on money lent is not due unless it has been brought into a stipulation; but in the case proposed, we must see whether it should not be understood as a contract of quasi-mandate between them rather than as money lent at interest, except for what he would have obtained beyond six percent; and indeed, that even the claim for the principal itself was not a claim for money lent, since, if Sempronius had either lost that money without fraud or held it idle, it must be said that he was under no obligation to pay anything on that account.
quare tutius esse praescriptis uerbis in factum actionem dari, praesertim cum illud quoque conuenisset, ut quod amplius praestitum esset, quam ex usuris redigeretur, sorti decederet: quod ipsum ius et causam pecuniae creditae excedat.
Therefore, it is safer for an action on the case with prescribed words to be granted, especially since it had also been agreed that whatever was paid in excess of what was collected from interest should be deducted from the principal, which itself exceeds the law and nature of money lent.