Jansenius's conclusion (book 4, chapter 7)
Thesis LXVI. From these and many similar passages Jansenius draws this conclusion: 'This weakness of willing, which arises from the delights of earthly things that press the will down to love created and carnal things, is the true reason why the delight of righteousness, that is, of the good work commanded, is necessary. Lifted up by it, the mind can either will strongly what it already wills feebly, or even will what it does not will.
'Unless God has softened the will with the sweetness of this delight, it will never be able either to fulfil or to will the righteousness of the commandment itself; and if it seems to perform some acts concerning the commandment, they will end only in the fruit of earthly desires and delights, or of its own pride. That heavenly sweetness smooths the way so that the will can get free of the birdlime of carnal things and fix itself on loving righteousness.
'It follows that if this delight is lacking, the will, as if numb and dead, can embrace nothing good at all; just as, conversely, in loving carnal things it can pursue nothing except what has delighted it.' De gratia Christi Salvatoris, book 4, chapter 7.
Latin
LXVI. Ex quibus & multis aliis similibus hanc conclusionem elicit Jansenius, Haec igitur volendi imbecillitas, quae ex terrenarum rerum delectationibus deorsum voluntatem ad creata atque carnalia diligenda deprimentibus, nascitur, vera causa est, cur delectatio justitiae, seu operis boni quod praecipitur, necessaria sit, qua sublevatus animus vel fortiter velle possit, quod jam tenuiter vult, vel etiam velle quod non vult. Cujus delectationis suavitate, nisi Deus voluntatem deliniverit, nunquam poterit ipsius praecepti justitiam vel implere, vel velle: sed si quos actus circa praeceptum exercere videatur, nonnisi in terrenarum concupiscentiarum ac delectationum, vel proprii fastus fructum terminabuntur. Coelestis enim illa suavitas mollit viam, ut voluntas ex carnalium rerum visco emergere possit, & seipsam in justitiam diligendam figere. Ex quo consequenter fit, ut si illa desit, voluntas veluti torpens ac mortua nihil omnino boni amplecti possit; quemadmodum etiam e contrario, nihil in carnalibus diligendo prosequi potest, nisi quod eam delectaverit. De gratia Christi salvatoris lib. 4. cap. 7.