Summa summae S. Thomae, Tomus II

I. Leaving aside the various acceptances of grace, here it is taken generally for whatever gift or benefit granted gratuitously, that is, out of mere benignity of God, not from justice or from our merits. Under this general acceptance of grace all natural gifts, namely nature itself and all its powers, can be called graces; for gratuitously God bestowed upon us to be, to live, to sense, to understand, to will, etc. These however, although in this wide sense they are called graces, cannot be called aids of grace, because aid supposes him who is helped and active powers which it helps.

II. Grace properly and in the common sense of Scripture and Church is taken for a gratuitous gift, whether habitual or actual, superadded to nature.

III. This grace, both habitual and actual, is of twofold order, natural namely and supernatural: natural, which moves toward good within the sphere of naturals, as if God infuse light of natural science, or move specially to cognition of natural things; supernatural, which helps by habit or motion unto those things which exceed the forces of nature, as while God infuses habit of faith or charity, or moves to the act of either. Between each this aid can still be further distinguished by another, as it were medium, which participates something of both, namely that it be natural as regards substance and supernatural as regards mode, e.g., while Christ illumined the man born blind: for the mode of working this effect was above the forces of nature, although the effect, consequently through grace, is substantially within the order of nature; for that sight was not of another kind than the sight of other men.

IV. Truly, because grace is divided against nature, grace resting precisely in natural good is less properly called grace: whence most properly is called grace either the supernatural habit infused, such as sanctifying grace and infused virtues, or the supernatural motion whereby God moves us as first mover in the order of grace to supernatural acts, or even that operation of God whereby he directs natural things to our salvation.

V. Grace taken for supernatural motion is twofold, moral and physical. Moral comes about by the showing forth of good, sometimes joined with infusion of light for perceiving it: it pertains to final cause. Physical comes about by an influx effectively and intrinsically reducing the faculty to act: it pertains to efficient cause. That God moves the will in both modes the Author teaches Iap., q. 105, a. 4, and elsewhere.

VI. Physical motion is sometimes a mere application of preexisting power and virtue, as when God moves the will of the just to act of charity. Sometimes, although it be application of power, it is nevertheless not application of virtue, because it does not preexist, but brings it with itself by way of passage, as while God moves the will of a sinner to act of attrition or contrition; since indeed that act is supernatural, and in that sinner no supernatural habit yet exists, it is necessary that that motion beginning conversion bring with it some supernatural virtue, not by way of permanent habit, but by way of transient passion.

VII. That physical motion which is a mere application of preexisting power and virtue is again twofold: one general, whereby God as first and universal mover applies faculties according to their exigency and mode to acts proportioned to them; another special, whereby God sometimes applies the mind of man to thinking or willing things which, although they do not exceed his forces, nevertheless, according to the accustomed course and disposition of the subject, man would neither think nor will them, and this both in naturals and in supernaturals.

VIII. General motion, whereby God as first and universal mover, both in order of nature and in order of grace, applies preexisting power and virtue, according to its exigency and the accustomed course of things, to acts proportioned to it, at first aspect seems not to pertain properly to special aid of grace, because it is given gratuitously, but from a certain connatural exigency: for as, collation of natural virtue supposed, there is owed to fire the motion or general concurrence premoving it to its proper act, to fire to burn, to sun to illuminate, so that without miracle it cannot be denied to it; so, although elevating virtue unto supernatural good has been given gratis to the just, that being supposed, there is owed in a certain way, according to common laws of Providence, the general motion applying it to acts proportioned to it.

Nevertheless, if we consider the matter more deeply, this general motion can and ought to be called in some true sense special aid of grace. For the understanding of this it must be observed that this general motion does not stand in the same mode in natural and voluntary agents. Natural agents have natural form whereby they are determined necessarily to one act suiting them, as fire to burn, sun to illuminate, and thus they demand general motion determining to the act proper to them. But voluntary agents have no natural form whereby they be determined necessarily to one act suiting them, but they are turnable to opposites and defectible from good connatural to them. Thus, although object of intellect be truth, of will in itself natural good, of will as instructed with infused virtues supernatural good; nevertheless intellect toward truth and will toward good whether natural or supernatural are borne flexibly and are defectible from it.

Whence, although general motion is owed to these powers whereby they sometimes attain their object, nevertheless not that they attain always and indefectibly. Therefore that this rather than that other be given to this one here and now, is from special grace.

Wherefore, if this general motion be considered respectively to nature in itself or as instructed with infused virtues, it must be called general motion, and not special gratuitous aid; because to general providence pertains moving each agent according to its mode, and since in man there is inclination, attenuated indeed and defectible, yet not wholly corrupted, toward good, there is owed to him motion whereby he be sometimes moved to good act suiting himself, and not always to evil. Whence that he be moved sometimes to good is not aid purely gratuitous, because in a certain way it is owed; nor special, because it is not from special benevolence and providence, but according to laws of common providence whereby he sometimes moves defectible natures to good of their nature, sometimes permits them to fail. Say the same of will informed by charity, in respect of supernatural good. But if this motion be considered respectively to the man to whom it is given before another, then in respect of this man it can and ought to be called special aid of grace; because, although nature, as was said, demands sometimes to be moved into good, nevertheless this man before another demands not that he be moved into good here and now rather than another. Whence that he be moved into good from which another fails and from which he himself could fail, is from special aid of grace, that is, freely conferred.

(This observation, which is open to anyone attending maturely, St. Thomas weighs and hands down, q. 24 de Veritate, a. 14, c, in these words: « Although man can do goods of this kind [namely proportionate to his nature] without grace gratum faciens, nevertheless he cannot do them without God, since nothing can issue into natural operation except by divine power; because secondary cause acts not except by power of first cause. And this is true both in natural agents and in voluntary ones. Yet this necessity stands in another mode in each. For God is cause of natural operation, inasmuch as he gives and conserves that which is principle of natural motion, as gravity in earth, which is principle of downward motion: » Although the Angelic Doctor mentions not general motion here, he nevertheless always supposes it and elsewhere expresses it.

That however this general motion does not suffice man that he act good connatural to himself, but that he needs special motion and direction, he explains thus pursuing: « But human will is not determined to any one operation, but stands indifferently toward many [that is, good and bad], and thus is after a manner in potency, unless moved through something active, either what is outwardly represented to it, as is good apprehended, or what is wrought interiorly in it, as is God himself, as Augustine says lib. de Gratia et libero Arbitrio, cap. 21, showing manifoldly God works in hearts of men. But all exterior motions [he says the same of interior ones] are moderated by divine providence according as he himself judges someone to be excited to good by these or those actions. Whence, if we wish to call grace of God not some habitual gift, but the very mercy of God, whereby he works interiorly the motion of mind and orders exterior things unto salvation of man; thus neither can man do any good without grace of God. » Therefore, according to St. Thomas, man, on account of indifference of human arbitrium, in order that he act good rather than evil, needs divine providence, which moderates motions to good according as it judges fitting, and mercy of God, whereby he works interiorly the motion of mind and orders exterior things to good. But no one can say this aid is owed to this man before another. Therefore it is gratuitous, because it is not given from merit, but from mercy. It is also special, because it is given not to all, however much in respect to nature in itself it be owed and general.

This observation is altogether necessary for untying the difficulties, otherwise most intricate, of this dissertation. For it removes ambiguities and equivocations on account of which many stumble and are deluded, and reconciles the apparently contrary opinions of Thomists, as will appear from what must be said.