Jansenius on Augustine: before faith, man's choice is captive and every act a sin
Jansenius, bishop of Ypres, hands this doctrine down as Augustine's and sets it out carefully in the volume he entitled Augustinus, in book 3 of On the state of fallen nature. In chapter 14 there he contends that this was the view of Augustine and his disciples, and so of the Catholic Church, which took up their teaching on this point against the Pelagians: after the fall man's choice is so captive and so stripped of the freedom to do good that whatever it does before grace, that is, before faith, from which freedom from sin begins, not only contributes nothing to piety and salvation but is not even morally good, since it is a true sin, properly so called.
In the same place he sets out as the undoubted view of Augustine and his disciples that no work that is good, even morally, can be done by human choice unless it is set free by grace, and not by any grace but by the grace of faith. Before faith, then, choice is not free to abstain from sin when it is thinking of acting here and now; whichever way it turns, it is held by a necessity of sinning that human strength cannot undo.
So, on this view, through Adam's fall man's freedom for good perished in such a way that before grace he cannot fulfil the whole law of moral righteousness, nor even one work of it. And his freedom to abstain from sin perished in such a way that he cannot escape the guilt of sin even in a single work. A necessity of sinning was therefore brought in, not in some acts only but in all.
For before grace, he holds, man not only cannot live wholly without sin, in that he necessarily falls at some time, but every act of his before he believes is a sin, whether he seems to flee the temptation to sin or to embrace it.
Latin
XXXIV. Hanc doctrinam ut Augustini tradit, & accurate exponit Jansenius Episcopus Iprensis in volumine quod inscripsit, Augustinus, De statu naturae lapsae libro tertio. Ibi enim capite decimo quarto pertendit, sensisse Augustinum ac ejus discipulos, & consequenter Ecclesiam Catholicam, quae doctrinam eorum in hac parte adversus Pelagianos amplexa fuit, arbitrium post lapsum hominis ita captivum esse, & boni faciendi libertate spoliatum, ut quicquid fecerit ante gratiam, hoc est, ante fidem, unde libertas a peccato incipit, non tantum nihil ad pietatem & salutem conferat, sed neque sit moraliter bonum, utpote quod sit verum & proprie dictum peccatum. Et ibidem hanc ut indubitatam Augustini & discipulorum ejus sententiam proponit, nullum, videlicet, opus bonum, ne quidem moraliter, ab humano arbitrio fieri posse, nisi per gratiam, non quamlibet, sed fidei liberetur: ut proinde ante fidem non sit ei liberum, a peccato, dum hic & nunc agere meditatur, abstinere, sed quocunque se verterit, quadam humanis viribus insolubili peccandi necessitate teneatur. Adeoque per Adami lapsum sic in homine periisse libertatem ad bonum, ut non solum non possit ante gratiam, totam justitiae moralis legem implere; sed nec quidem unum opus ejus: & ita periisse libertatem abstinendi a peccato, ut nec in uno quidem opere peccati culpam possit effugere: ac proinde inductam esse peccandi necessitatem, non tantum in aliquibus, sed in omnibus actibus. Ante gratiam enim non solum hominem non posse sine omni peccato vivere, eo quod necessario aliquando cadat; sed omnem ejus actum, antequam credat, peccatum esse, sive peccati tentationem fugere, sive amplecti videatur.