Prosper

Prosper of Aquitaine, often called Prosper Tiro in the manuscripts of his works, was a Latin Christian writer of the fifth century whose life is known almost entirely from his own books and from a brief notice by Gennadius of Marseille. He came from Aquitaine, the southwestern region of Roman Gaul, and his cognomen Aquitanus is the principal evidence for his origin. No contemporary source records the city of his birth or an exact year. He received a classical education of a high order, as his hexameter poetry and his control of rhetorical prose make clear. By the later 420s he was living in the milieu of Marseille, then a focus of monastic life and of theological debate in southern Gaul. There he encountered strong resistance to the late teaching of Augustine of Hippo on grace and predestination among monks and clergy who feared that Augustine's doctrine undermined human effort and the call to ascetic striving.

In about 429 Prosper and a friend named Hilary addressed letters to Augustine at Hippo describing this opposition and asking the aged bishop to clarify his position. Augustine answered with the two books On the Predestination of the Saints and On the Gift of Perseverance, among his last works. After Augustine died in 430, Prosper took up the defense of his master's memory. He wrote the poem Carmen de ingratis against those he regarded as ungrateful to grace; a set of epigrams drawn from Augustine; several series of Responsiones answering Gallic objections; and the Contra collatorem, a direct attack on the thirteenth of John Cassian's Conferences. He also assembled the Sententiae extracted from Augustine's writings, an anthology that circulated widely in the Middle Ages. Throughout these works Prosper insisted that every beginning of faith and every act of perseverance is a gift of God, while he tried to avoid formulations that would make God the author of sin or would deny the genuine offer of salvation.

Prosper subsequently left Gaul for Rome. The date of the move is not precisely known, but he was in the city during the pontificate of Leo I (440-461) and appears to have served in the papal administration, probably as a notary. Medieval writers made him Leo's secretary and credited him with a hand in the Tome to Flavian of 449, the letter that defined the Christological faith of the Roman see before the Council of Chalcedon; modern historians treat that attribution as unproven, though Prosper's presence in the Leonine circle is not in doubt. In Rome he produced a Chronicle that continues Jerome's Chronicle down to the year 455, incorporating notices of popes, emperors, and the Vandal capture of Rome in that year. He also wrote De vocatione omnium gentium, a treatise arguing that God wills the salvation of all peoples and that the delay in the conversion of some nations belongs to the hidden order of providence. Many scholars consider this his most measured theological statement. A collection of anti-Pelagian capitula associated with Pope Celestine I has likewise been connected with Prosper's Roman activity.

Neither the year nor the place of Prosper's death is attested in a contemporary record. Because his Chronicle stops at 455 and no later work can be securely assigned to him, historians generally conclude that he died in or soon after that year, and Rome is the most plausible location. He is not known to have been ordained to any rank of the clergy. Later liturgical tradition sometimes honors him as a saint, most often on 25 June, a date that the Roman Martyrology assigns instead to Prosper, a fifth-century bishop of Reggio Emilia, so that the two men have frequently been confused. Prosper of Aquitaine was never a bishop, never a pope, and belonged to no religious order. His historical importance rests on his role as the chief advocate of Augustinian teaching on grace in the generation after Augustine, on the documentary value of his Chronicle for the mid-fifth century, and on the influence his anthologies and treatises exercised on medieval and early modern debates about predestination.