Efficacy depends on free choice, even in the composite sense
Thesis LXXXI. On his view, then, the division of sufficient aid into efficacious and inefficacious is taken from the effect, and the effect depends on the freedom of choice. So it lies with human choice, and is placed in its power, whether the aid of grace, sufficient of itself, becomes efficacious or remains inefficacious.
Sufficient aid is called efficacious when choice is converted with it by its own freedom, although, with nothing in the aid preventing it, choice could have remained unconverted, and that in the composite sense and not only in the divided sense. It is called inefficacious when choice, by the same freedom, is not converted with it, although it could have been converted and could actually and in fact have elicited the act of conversion without any further aid of God's grace.
'We assert,' he says, 'that whether the aids of prevenient and assisting grace granted by the ordinary law to those still on their pilgrimage are efficacious or inefficacious for conversion or justification depends on the free consent and cooperation of our choice with them. It is therefore in our free power either to make them efficacious, by consenting and cooperating with them toward the acts by which we are disposed for justification, or to make them inefficacious, by withholding our consent and cooperation, or even by eliciting the contrary dissent.' Same book, question 14, article 13, disputation 40.
Latin
LXXXI. Itaque, ex illius mente, Divisio auxilii sufficientis, in efficax & inefficax, sumitur ab effectu, qui ab arbitrii libertate pendet. Adeoque penes humanum arbitrium situm est, & in illius potestate positum, ut auxilium gratiae, quod ex se sufficiens est, vel fit efficax, vel maneat inefficax. Illudque auxilium sufficiens efficax dicitur, cum quo arbitrium pro sua libertate convertitur, cum tamen, nihil ex auxilio impediente, potuerit non converti, idque in sensu composito, non tantum in sensu diviso: illud vero inefficax dicitur, cum quo arbitrium, pro eadem sua libertate, non convertitur, cum tamen potuerit converti, & absque ullo alio gratiae Dei auxilio reapse & de facto, conversionis actum elicere. Asserimus, inquit, auxilia praevenientis atque adjuvantis gratiae, quae lege ordinaria viatoribus conceduntur, quod efficacia, aut inefficacia ad conversionem, seu justificationem sint, pendere a libero consensu & cooperatione arbitrii nostri cum illis, atque adeo in libera potestate nostra esse, vel illa efficacia reddere, consentiendo & cooperando cum illis, ad actus quibus ad justificationem disponimur, vel inefficacia illa reddere, continendo consensum & cooperationem nostram, aut etiam eliciendo contrarium dissensum. Ejusdem libri quaest. 14. art. 13. disp. 40.