Isagoge ad lectionem epistolarum divi Pauli apostoli, qua compositionis oeconomia, et germana dispositio indicatur. Opusculum recens. Benedicto Aretio authore.

it is, yet there exists a law and custom of Circumcision, in which names were imposed simultaneously on the eighth day: thus, this can be demonstrated as a consequence. This cannot be said of the name of Paul, since they did not impose twin names on their infants at the same time: therefore, one must proceed here with conjectures and a probable opinion. Jerome in the Ecclesiastical Writers. Here Jerome indicates that this name happened to him because of a deed. For when he had converted Sergius Paulus, the Proconsul of Cyprus, as it is in Acts 13, from that fact, he was always called Paul thereafter. Nor does it obstruct this opinion that he is called Paul in the same chapter before he had converted the Proconsul: for Luke wrote the history afterwards, nor was he compelled, against the laws of narration, which gave him the freedom, for the sake of the man, to call him Paul, whose history he was about to relate shortly, so that it might be clear to the reader what he ought to hope for concerning the outcome in this narrative.