Here’s something from the Catholic Encyclopedia:
"According to Jansenism, the mere absence of the state of grace and love (status gratiae et caritatis) branded as sins all the deeds of the sinner, even the ethically good ones (e.g., almsgiving). This was the lowest ebb in its disparagement and depreciation of the moral forces in man; and here, too, Baius had paved the way. The possession of sanctifying grace or theological love thus became the measure and criterion of natural morality. Taking as his basis the total corruption of nature through original sin (i.e. concupiscence) as taught by early Protestantism, Quesnel, especially (Prop. xliv in Denzinger, n. 1394), gave the above-expressed thought the alleged Augustinian form that there is no medium between love of God and love of the world, charity and concupiscence, so that even the prayers of the impious are nothing else but sins. (Cfr. Prop. xlix: “Oratio impiorum est novum peccatum et quod Deus illis concedit, est novum in eos judicium”). The answer of the Church to such severe exaggerations was the dogmatic Bull, “Unigenitus” (1713), of Pope Clement XI. The Council of Trent (Sess. VI, can. vii) had however already decreed against Martin Luther: “Si quis dixerit, opera omnia quae ante justificationem fiunt . . . vere esse peccata . . . anathema sit” (If anyone shall say that all the works done before justification are indeed sins, let him be anathema). Moreover, what reasonable man would concede that the process of justification with its so-called dispositions consists in a long series of sins? And if the Bible, in order to effect the conversion of the sinner, frequently summons him to contrition and penance, to prayer and almsdeeds, shall we admit the blasphemy that the Most Holy summons him to the commission of so many sins?
The Catholic doctrine on this point obstinately adhered to through all the centuries, is so clear that even an Augustine could not have departed from it without becoming a public heretic. True, Baius and Quesnel succeeded in cleverly concealing their heresy in a phraseology similar to the Augustinian, but without penetrating the meaning of Augustine. The latter, it must be conceded, in the course of the struggle with self-confident Pelagianism, ultimately so strongly emphasized the opposition between grace and sin, love of God and love of the world, that the intermediary domain of naturally good works almost completely disappeared. But Scholasticism had long since applied the necessary correction to this exaggeration. That the sinner, in consequence of his habitual state of sin, must sin in everything, is not the doctrine of Augustine. The universality of sin in the world which he contemplated, is not for him the result of a fundamental necessity, but merely the manifestation of a general historical phenomenon which admits of exceptions (De spir. et lit., c. xxvii, n. 48). He specifically declares marital love, love of children and friends to be something lawful in all men, something commendable, natural and dutiful, even though Divine love alone leads to heaven. He admits the possibility of these natural virtues also in the impious: “Sed videtis, istam caritatem esse posse et impiorum, i.e. paganorum, Judaeorum, haereticorum” (Serm. cccxlix de temp. in Migne, P.L., XXXIX, 1529)."
From:
newadvent.org/cathen/06689x.htm
I think the Papal Bull in question is just condemning the idea that without grace everything is sin, which is more similar to the Total Depravity of Protestants and is not Catholic theology. It is not, however, denying grace since grace is necessary, as the Council of Trent says, that we cannot achieve justice in God’s sight. So doing good and doing good that is meritorious are two different things.
Pax Christi tecum.
