As far as the fragments' 'cover-text' is concerned, Jerome's assertion creates major methodological problems. First, the fragments represent only the threatening aspect of the treatise to which Jerome could not help alluding. The fragments are thus merely a metonymy for Porphyry's discourses as Jerome saw them. Jerome also uses Porphyry to show his own knowledge in front of Church opponents. In his Commentary on Matthew 15.17, Jerome mentions how Porphyry and others used a declaration made by Jesus about the processing of food in the body in the hope of proving his human condition, that is 'everything that goes into the mouth passes into the belly and is discharged into the drain'. According to Jerome, Porphyry couched his attacks on the Book of Daniel in book 12 of his discourses. Jerome's Commentary on Daniel preserves the most extensive fragments of Against the Christians.