Vázquez: an act is referred to God by its nature, without a further intention
Close to this is Vázquez's teaching. For our works to be good and honourable, he says, they must indeed be referred to God as last end, but not by some prior act of will by which they could be said to be referred habitually; they are referred by the very nature of the work, without any further movement of the will.
So for an unbeliever to do a good work it is enough that he knows it is good and loves it for the sake of virtue's own honesty; by that very fact the work is sufficiently referred to God. Disputation just cited, chapters 2 and 3.
Latin
XXIX. Quibus affine est quod docet Vasquez, nempe ad hoc ut opera nostra sint bona & honesta, debere quidem referri in Deum ut ultimum finem, non tamen voluntate aliqua praecedente, ex qua habitu dicantur referri, sed ex sola natura operis, sine alia motione voluntatis. Adeoque sufficere ad hoc ut infidelis bonum opus faciat, si sciat illud esse bonum & propter ipsam virtutis honestatem illud amet: hoc ipso enim tale opus sufficienter ad Deum referri. Nuper citata Disput. cap. 2. & 3.