Prosper (4), St., a native of Aquitaine, not certainly known to have
been in holy orders; probably born c. 403. About 426–429 he removed to
Marseilles, where he lived as a monk until 440. Some time between 420 and 427
John Cassian put forth in his Collationes a doctrine concerning grace
and free will contrary to that taught by St. Augustine. This doctrine was taken
up warmly by many monks at Marseilles, and both Prosper and Hilary (as to whom
see further on), afraid lest a doctrine they believed erroneous should become
prevalent among the monks, were thinking of writing to Augustine to request
him to explain some of his statements. In the meantime came out Augustine's
Correptione et Gratia, by which Prosper hoped all doubts would be settled. But those who thought differently only became more obstinate in their opposition. Although Prosper had never seen Augustine, he had written to him by Leontius, a deacon, and received a reply, but neither letter nor reply has survived. He now wrote again to him in 428, as also did Hilary, and his reply to these letters is contained in the consecutive treatises de Praedestinatione Sanctorum and de Dono Perseverantiae, written either in 428 or 429 (see Aug. Epp. 225, 226; and Opp. vol. x. pp. 947–1034, ed. Migne). [.] Augustine died 430, and the opponents of his doctrine in Gaul professing willingness to abide by the decision of the Roman pontiff, Hilary and Prosper went to Rome and brought back a letter from Celestine I. to the Gallic bishops, Venerius of Marseilles, Marinus, Leontius of Fréjus, Auxentius of Nice, Auxonius of Viviers, and Arcadius of Venice. In this he speaks of Hilary and Prosper as men "quorum circa Deum nostrum solicitudo laudanda est," and reproved, but without effect, the indiscretion and ill-informed zeal of their opponents (Coelest. Ep. xxi. 1, 2). To this letter are subjoined in some editions a series of so-called decisions of the apostolic see concerning grace and free will, which, however, cannot be regarded as authentic. When Leo I. returned from his mission into Gaul, 440, to be made pope, he persuaded Prosper to accompany him to Rome, and employed him as his secretary (notarius). Photius says that he confuted the Pelagians at Rome in the time of Leo, and a MS. of the monastery of Corbey adds, but without mention of authority, that he was sent by him on a similar errand into Campania to oppose Julian of Eclanum. Gennadius says that he was the real author of the epistle of Leo against Eutyches concerning the incarnation of Christ. The chronicle of Marcellinus shews him alive in 463. Fulgentius (ad. Mon. i. c. 30) speaks of him as "eruditus et Sanctus"; Photius (Biblioth. 54) as one who was truly a man of God, but with no other title than Πρόσπειρός τις, who confuted the Pelagians in the time of Leo. Gennadius, no friend to him, speaks of him (de Scr. Ecc. 84) as "sermone scholasticus et assertionibus nervosus" (Butler, Lives of Saints, June 25; Ceillier, vol. x. p. 278). The letter of Prosper to Augustine describes the view taken at Marseilles and elsewhere concerning predestination. Those who adopted it, he says, believe that mankind has sinned in Adam, and that without God's grace there can be no salvation for any one. God offers salvation to all, so that they who attain faith and receive baptism are in the way of being saved. But before the creation of the world God foreknew who would believe and be saved, and predestined them to His kingdom, being called by grace and worthy of being chosen and of going out of life sound in faith. No man, therefore, need despair of salvation, but this selection on God's part makes human exertion needless either for recovery from sin or for progress in holiness. Thus a doctrine of fatal necessity is introduced. They also think that men can by their own merit, by praying, beseeching, knocking, attain that state of grace in which we are born anew unto Christ. Infants dying without baptism will be saved or not according as God foreknows what their conduct would have been if they had grown up. Christ died for the whole race of mankind, but some miss this salvation because they are known beforehand to have no inclination to receive it. They also deny that the merits of saints proceed from divine grace, and that the number of the elect can be either increased or diminished, and they assert that the only way in which a man is called either to repentance or to progress in holiness is by the exercise of his own free will. They thus place obedience before grace, and the first step towards salvation in him who is to be saved, not in Him Who saves.