The first sure date in the life of Prosper is that of his letter to St. Augustine written under the following circumstances.
Prosper of Aquitaine, TIRO.—The first sure date in the life of Prosper is that of his letter to St. Augustine written under the following circumstances. In 428 or 429 a certain Hilary wrote to St. Augustine in reference to difficulties raised against his doctrine in Marseilles and the neighborhood. Hilary distrusted his own ability to give St. Augustine a proper grasp of the situation, so he prevailed with a friend whom he described as a man distinguished tum moribus, tum eloquio et studio (for morals, eloquence and zeal) to write also. This friend was Prosper who, though he had never met St. Augustine, had corresponded with him. The two letters were despatched at the same time, and may be said to have opened the semi-Pelagian controversy. St. Augustine replied to the appeal made to him with the two treatises, "De Praedestinatione" and "De Dono Perseverantiae." It was about this time that Prosper wrote what was really a short treatise on grace and free will, under the form of a letter to a certain Rufinus, and his great dogmatic poem of over a thousand hexameter lines, "De Ingratis", on the semi-Pelagians, who were enemies of grace and are represented as reviving the errors of Pelagianism. Two epigrams of twelve and fourteen lines respectively against an "obtrectator" of St. Augustine seem also to have been composed in the lifetime of the saint. Three opuscules belong to the time immediately after the death of St. Augustine (430): (I) "Responsiones ad capitula Gallorum". These capitula were a series of fifteen propositions attributed to St. Augustine by his opponents, e.g. "the Savior was not crucified for the whole world." To each Prosper appended a brief responsio, and concluded the treatise with fifteen corresponding sententiae, setting forth what he held to be the true doctrine. (2) "Ad capitula objectionum Vincentianarum responsiones". The Vincentian objections were like the "capitula Gallorum", but more violent, and they attacked Prosper as well as St. Augustine. Prosper replied to them one by one. The Vincent who drew them up was probably Vincent of Lerins (Barden-hewer, Hauck, Valentin), but some writers have contested this point. (3) "Pro Augustino responsiones ad excerpta Genuensium". This is an explanation of certain passages in St. Augustine's treatises, "De praedest" and "De dono persev.", which presented difficulties to some priests at Genoa who asked Prosper for an explanation of them. These three opuscula are placed by Bardenhewer after Prosper's visit to Rome.
In 431 Prosper and a friend went to Rome to invoke the aid of St. Celestine. The pope responded with the Letter, "Apostolici Verba", addressed to the bishops of Gaul, in which he blamed their remissness with regard to the enemies of grace, and eulogized St. Augustine. On returning to Gaul, Prosper again took up the controversy in his "De Gratia Dei et liberoarbitrio; liber contra collatorem". The "Collator" was Cassian who in his "Conferences" had put forward semi-Pelagian doctrine. The date of this, the most important of Prosper's prose writings, can be fixed at about 433, for the author speaks of twenty years and more having elapsed since the beginning of the Pelagian heresy, viz., according to his "Chronicle", A.D. 413. An ironical epitaph on the Nestorian and Pelagian heresies was probably composed shortly after the Council of Ephesus. The "Expositio psalmonum" is substantially an abridgment of the "Enarrationes" of St. Augustine. It probably comprised the whole psalter, but as it has come down to us it only comments on the last fifty. The "Sententiae ex Augustine delibatae" are a collection of sayings extracted from the writings of St. Augustine. In framing them Prosper as a rule dealt rather freely with the text of St. Augustine, chiefly in the interests of rhythmic prose. Canons 9, 14, 15, 16, 18 of the second Council of Orange were taken from sentences 22, 222, 226, 160, 297. The epigrams are a number of the sentences turned into verse. Both these works must have been composed about the time of the Council of Chalcedon, and probably, therefore, in Rome, whither Prosper was summoned about A.D. 440 by Leo the Great. According to Gennadius (De vir. ill., 84), he was said to have drawn up the letters written by this pope against Eutyches.
The "Chronicle" of Prosper, from the creation to A.D. 378, was an abridgment of St. Jerome's, with, however, some additional matter, e.g. the consuls for each year from the date of the Passion. There seem to have been three editions: the first continued up to 433, the second to 445, the third to 455. This chronicle is sometimes called the "Consular Chronicle", to distinguish it from another ascribed to Prosper where the years are reckoned according to the regnal years of the emperors and which is accordingly called the "Imperial Chronicle". This is certainly not the work of Prosper. It was compiled by a man whose sympathies were not with St. Augustine, and who was formerly supposed to be Tiro Prosper and not Prosper of Aquitaine, but this theory has broken down, for Prosper of Aquitaine in some MSS. of the "Consular Chronicle" is called Tiro Prosper. With regard to the writings of Prosper not yet mentioned, Valentin pronounces the poem "De providentia" to be genuine; the "Confessio S. Prosperi", and "De vocatione gentium" to be probably genuine; the "Epistola ad Demetriadem", the "Praeteritorum sedis Apostolicae auctoritates de Gratia Dei, etc." appended to the Epistle of St. Celestine, and the "Poema mariti ad conjugem" to be very likely genuine. The "De vita contemplativa" and "De promissionibus etc." are not by Prosper, according to Valentin and Hauck. Hauck agrees with Valentin with regard to the "Poema mariti" and the "Confessio", but pronounces against the "De vocatione", the "De providentia", and on the other doubtful works expresses no view.
The story that Prosper was Bishop of Reggio in Italy was exploded by Sirmondi and others in the seventeenth century. For the origin of this legend see Dom Morin in "Rèvue bènèdictine", XII, 241 sqq. Prosper was neither bishop nor priest. The question whether he mitigated the severity of St. Augustine's doctrine has been much debated. The difference of opinion probably arises more from different views regarding St. Augustine's doctrine than from different interpretations of Prosper's. The general trend of opinion among Catholic writers seems to be in favor of the affirmative view, e.g. Kraus, Funk, Bardenhewer, Valentin, and others.
F. J. BACCHUS