[ULPIANUS libro quadragesimo ad Sabinum. ] §26.8.7.prQuod dicimus in rem suam auctoritatem accommodare tutorem non posse, totiens uerum est, quotiens per semet uel subiectas sibi personas adquiritur ei stipulatio: ceterum negotium ei geri per consequentias, ut dictum est, nihil prohibet auctoritas.
[ULPIAN, in the fortieth book of his Commentary on Sabinus.] Our statement that a tutor cannot grant authority in his own interest is true only so often as a stipulation is acquired for him either through himself or through persons subjected to his power; otherwise, as has been said, authority in no way prevents business being transacted for him as a consequence.
§26.8.7.1Si duo rei sint stipulandi et alter me auctore a pupillo stipuletur, alter altero tutore auctore, dicendum est stipulationem ualere, sic tamen, si auctoritas tutoris unius sufficiat: ceterum si non sufficiat, dicendum erit inutilem esse stipulationem.
If there are two joint-creditors, and one stipulates from the ward with my authorization, and the other with the authorization of another tutor, it must be held that the stipulation is valid, provided, however, that the authority of a single tutor is sufficient; but if it is not sufficient, it must be held that the stipulation is of no effect.
§26.8.7.2Si et pater et filius qui in potestate eius fuit tutores fuerunt et pater sit stipulatus filio auctore, nullius momenti erit stipulatio idcirco, quia in rem patris auctor esse filius non potest.
If both a father and his son who was in his power were tutors, and the father stipulated with the authorization of the son, the stipulation will be of no effect for this reason, because a son cannot grant authority in his father's interest.