On this view every act without grace is flawed; Vázquez states the precise question
On these doctors' view, then, man in the state of sin can do nothing without God's grace that is truly a work of virtue and deserves to be called good and honourable without qualification. In that state, whatever works a man does, however fine and outwardly honourable they look, are made vicious by the lack of some circumstance and take on something of the character of sin.
What grace is needed for corrupt man to act well and give true obedience to the moral law, Vázquez explains carefully in the disputation just cited. At the start of chapter 1 he points out that the question is not whether habitual grace, the grace that makes acceptable and justifies, which he places in charity, is needed for acting well by the moral law. Nor is it whether all the works of a man in sin are sins, nor even whether faith is needed to act well; it is only whether man can act virtuously without some help of grace.
'In this controversy,' he says, 'our question will not be whether an unbeliever can do some good things. We will not dispute whether some good can be done without charity, or whether all the works of a man in sin are sins or he can do some good ones. The controversy now is whether man can do any good work according to virtue without the help of God's grace; and that is a very different question.'
Latin
XXI. Igitur ex horum Doctorum sententia, homo in statu peccati absque Dei gratia nihil operari potest quod vere sit virtutis opus, quodque simpliciter bonum & honestum dici mereatur: quoniam in eo statu, quaecunque opera ab homine fiunt, ut ut speciosa sint, & extrinsecus honesta videantur, ex circumstantiae alicujus defectu vitiosa redduntur, & quandam peccati rationem contrahunt. Quae gratia autem sit necessaria ad hoc, ut homo corruptus bene operari possit & verum legi morali obsequium praestare, studiose explicat Vasques modo citata disputatione. Etenim initio capitis primi monet quaestionem hic non esse, An gratia habitualis & gratum faciens atque justificans, quae juxta ipsum in charitate consistit, necessaria sit ad hoc, ut quis secundum legem moralem bene operetur. Neque etiam quaeri utrum omnia opera ejus qui in peccato est, peccata sint. Imo neque an fides necessaria sit ad bene operandum, sed solum an sine quodam gratiae auxilio homo possit secundum virtutem operari. Caeterum, inquit, in hac controversia quaestio nobis futura non est, an infidelis aliqua bona facere possit; neque disputandum erit, an sine charitate aliquod bonum fieri queat; neque utrum omnia opera existentis in peccato peccata sint, an aliqua bona ille efficere possit: sed controversia nunc est, an sine auxilio gratiae Dei possit homo aliquod bonum opus, secundum virtutem, operari; quae sane quaestio longe diversa est.