Nor do they mean the act can fail to follow upon efficacious grace and a settled judgment
Further, when they say that a free agent, given everything required beforehand for acting, can act or not act, and do this or that, they do not mean that the will's act can fail to follow once everything required for some act of will is in place, including the motion of God's grace and the practical judgment of the mind, so that the absence of the act could coexist with everything that moves and disposes the will to act.
They admit it is impossible for God to move someone by his effective grace to an act of godliness and for that act not to be produced, or for someone, having weighed everything, to judge that he must do and seek something here and now and then not do and seek it.
All they mean is this. The man who is moved to act in the way described will act infallibly and surely, and it cannot happen that he does not act; yet he still keeps in himself a real power not to act and to act otherwise. That power remains not only in someone fully prepared and ready to act but in someone actually acting. For although an act cannot coexist with its own absence or with a contrary act, the power to the contrary act can perfectly well coexist with it, as has been stressed many times already.
Latin
XXV. Ac praeterea quum dicunt agens liberum, positis omnibus ad agendum praerequisitis, posse agere vel non agere, hoc, aut illud agere, mens eorum non est quod positis omnibus quae ad aliquem actum voluntatis praerequiruntur, inter quae locum habet gratiae divinae motio, & practicae mentis judicium, possit actio voluntatis non sequi, & sic carentia actionis ejus jungi cum omnibus illis per quae voluntas ad agendum movetur atque disponitur. Fatentur enim impossibile esse ut Deus hominem quempiam gratia sua efficaci ad aliquem actum pietatis moveat, & tamen actus ille ab eo non eliciatur: aut ut aliquis, omnibus expensis, judicet hic & nunc istud sibi agendum & appetendum esse, & tamen idem istud non agat & appetat; Verum id solum sibi volunt illum qui, qua jam dictum est ratione, ad agendum movetur, licet infallibiliter & certo acturus sit, & contingere non possit ut non agat; illum, inquam, nihilominus veram in se retinere potentiam non agendi, & aliter agendi, quae manet non solum in eo qui proxime ad agendum paratus & dispositus est, sed in eo ipso qui jam de facto agit; quoniam etsi cum actu aliquo stare non possit ejus carentia, aut actus contrarius, optime tamen cum eo componi potest potentia ad actum illum contrarium, ut jam pluries inculcatum fuit.