Cap. III Sol. Rat. 12: can the elect fall? fragility vs maintaining hand of God — Peter
Next the Jesuit's later claim: if after God's efficacious decree the elect freely work toward salvation, an elect person can fall from salvation and God's decree can be made void — for whoever freely perseveres can fail to persevere, so can fail to be saved. I answer: the sayings Whoever freely acts can fail to act and Whoever is freely saved can fail to be saved, if they mean a possibility of not acting and not reaching salvation that can arise from human fragility considered in itself, we grant such a possibility of perishing still clings to the elect. But if they mean that, despite God's upholding hand, that weakness can go into act so that in the event they might not persevere in faith and holiness or reach eternal life — we deny entirely that, once God's efficacious decree for their salvation is posited, such a possibility of perishing belongs to them. Augustine shows it by Peter (De corr. Et grat. 8): as a weak, changeable man he could fall from faith, holiness, and salvation — but given that God had decreed, for Christ's prayer, to inspire in him a most free, strong, unconquered, persevering will in the faith, on that hypothesis he could not perish and could not but most freely persevere.
Latin
Accedo ad illud posterius dictum Jesuitae, nimirum, Posse electum a salute excidere, et decretum Dei irritum fieri, si modo dicamus post efficax Dei decretum electos libere operari ad consecutionem salutis. Nam qui libere perseverat, potest non perseverare; potest ergo non salvari, et sic sequetur quod est impossibile, decretum Dei irritum reddi posse. Respondeo, Haec pronunciata, Qui libere operatur, potest non operari; Qui libere salvatur, potest non salvari; unde infertur decretum Dei efficax posse fieri irritum: haec, inquam, pronunciata, si respiciant possibilitatem non operandi, et non perveniendi ad salutem, quatenus ex humana fragilitate per se considerata nasci et oriri possit, agnoscimus ipsis electis adhaerescere talem pereundi, et a vita aeterna excidendi possibilitatem: Sed si referantur ad possibilitatem non operandi aut pereundi, quasi, non obstante manutinentia Divina, possit haec imbecillitas electorum in actum exire, atque sic eos quoad eventum posse non perseverare in fide et sanctitate, posse non pervenire ad vitam aeternam, negamus prorsus, posito decreto Dei efficaci de illorum salute, talem possibilitatem pereundi illis competere. Exemplo Petri hoc declaravit Augustinus; Potuit ille, ut homo infirmus et mutabilis, a fide et sanctitate et a salute deficere: sed hoc posito, quod Deus decreverat illi propter Christi orationem inspirare liberrimam, fortissimam, invictissimam, perseverantissimam in fide voluntatem, ex hac hypothesi non potuit perire, non potuit non liberrime perseverare; Vide De corr. et grat. c. 8.