Aliqui habitus homini a Deo infunduntur, quia aliqui habitus sunt quibus homo bene disponitur ad finem excedentem facultatem humanae naturae, qui est ultima et perfecta hominis beatitudo, ut supra dictum est.
Some habits are infused by God into man, because there are some habits by which man is disposed to an end which exceeds the proportion of human nature, namely, the ultimate and perfect happiness of man, as stated above (q5 a5).
Et quia habitus oportet esse proportionatos ei ad quod homo disponitur secundum ipsos, ideo necesse est quod etiam habitus ad huiusmodi finem disponentes, excedant facultatem humanae naturae. Unde tales habitus nunquam possunt homini inesse nisi ex infusione divina, sicut est de omnibus gratuitis virtutibus.
And since habits need to be in proportion with that to which man is disposed by them, therefore is it necessary that those habits, which dispose to this end, exceed the proportion of human nature. Wherefore such habits can never be in man except by Divine infusion, as is the case with all gratuitous virtues.
Alia ratio est, quia Deus potest producere effectus causarum secundarum absque ipsis causis secundis, ut in primo dictum est. Sicut igitur quandoque, ad ostensionem suae virtutis, producit sanitatem absque naturali causa, quae tamen per naturam posset causari, ita etiam quandoque, ad ostendendam suam virtutem, infundit homini illos etiam habitus qui naturali virtute possunt causari. Sicut apostolis dedit scientiam Scripturarum et omnium linguarum, quam homines per studium vel consuetudinem acquirere possunt, licet non ita perfecte.
The other reason is, because God can produce the effects of second causes, without these second causes, as we have said in S.T. I, 105, 6. Just as, therefore, sometimes, in order to show His power, He causes health, without its natural cause, but which nature could have caused, so also, at times, for the manifestation of His power, He infuses into man even those habits which can be caused by a natural power. Thus He gave to the apostles the science of the Scriptures and of all tongues, which men can acquire by study or by custom, but not so perfectly.
Hoc quod Deus in omnibus operatur secundum modum eorum, non excludit quin Deus quaedam operetur quae natura operari non potest, sed ex hoc sequitur quod nihil operatur contra id quod naturae convenit.
That God works in all according to their mode, does not hinder God from doing what nature cannot do, but it follows from this that He does nothing contrary to that which befits nature.
Actus qui producuntur ex habitu infuso, non causant aliquem habitum, sed confirmant habitum praeexistentem, sicut medicinalia remedia adhibita homini sano per naturam, non causant aliquam sanitatem, sed sanitatem prius habitam corroborant.
Acts produced by an infused habit, do not cause a certain habit, but strengthen the already existing habit; just as the remedies of medicine given to a man who is naturally healthy, do not cause a kind of health, but give new strength to the health he had before.