Thomas Aquinas - Summa Theologica, Part I-II (Pars Prima Secundae)

On the contrary, the Philosopher says (Ethic. ii, 3) that a virtuous man acts as he should, and when he should, and so on in respect of the other circumstances. Therefore, on the other hand, the vicious man, in the matter of each vice, acts when he should not, or where he should not, and so on with the other circumstances. Therefore human actions are good or evil according to circumstances.

I answer that, In natural things, it is to be noted that the whole fulness of perfection due to a thing, is not from the mere substantial form, that gives it its species; since a thing derives much from supervening accidents, as man does from shape, color, and the like; and if any one of these accidents be out of due proportion, evil is the result. So it is with action. For the plenitude of its goodness does not consist wholly in its species, but also in certain additions which accrue to it by reason of certain accidents: and such are its due circumstances. Wherefore if something be wanting that is requisite as a due circumstance the action will be evil.

Reply Obj. 1: Circumstances are outside an action, inasmuch as they are not part of its essence; but they are in an action as accidents thereof. Thus, too, accidents in natural substances are outside the essence.

Reply Obj. 2: Every accident is not accidentally in its subject; for some are proper accidents; and of these every art takes notice. And thus it is that the circumstances of actions are considered in the doctrine of morals.

Reply Obj. 3: Since good and being are convertible; according as being is predicated of substance and of accident, so is good predicated of a thing both in respect of its essential being, and in respect of its accidental being; and this, both in natural things and in moral actions. ________________________

FOURTH ARTICLE [I-II, Q. 18, Art. 4]

Whether a Human Action Is Good or Evil from Its End?

Objection 1: It would seem that the good and evil in human actions are not from the end. For Dionysius says (Div. Nom. iv) that "nothing acts with a view to evil." If therefore an action were good or evil from its end, no action would be evil. Which is clearly false.

Obj. 2: Further, the goodness of an action is something in the action. But the end is an extrinsic cause. Therefore an action is not said to be good or bad according to its end.

Obj. 3: Further, a good action may happen to be ordained to an evil end, as when a man gives an alms from vainglory; and conversely, an evil action may happen to be ordained to a good end, as a theft committed in order to give something to the poor. Therefore an action is not good or evil from its end.

On the contrary, Boethius says (De Differ. Topic. ii) that "if the end is good, the thing is good, and if the end be evil, the thing also is evil."

I answer that, The disposition of things as to goodness is the same as their disposition as to being. Now in some things the being does not depend on another, and in these it suffices to consider their being absolutely. But there are things the being of which depends on something else, and hence in their regard we must consider their being in its relation to the cause on which it depends. Now just as the being of a thing depends on the agent, and the form, so the goodness of a thing depends on its end. Hence in the Divine Persons, Whose goodness does not depend on another, the measure of goodness is not taken from the end. Whereas human actions, and other things, the goodness of which depends on something else, have a measure of goodness from the end on which they depend, besides that goodness which is in them absolutely.

Accordingly a fourfold goodness may be considered in a human action. First, that which, as an action, it derives from its genus; because as much as it has of action and being so much has it of goodness, as stated above (A. 1). Secondly, it has goodness according to its species; which is derived from its suitable object. Thirdly, it has goodness from its circumstances, in respect, as it were, of its accidents. Fourthly, it has goodness from its end, to which it is compared as to the cause of its goodness.

Reply Obj. 1: The good in view of which one acts is not always a true good; but sometimes it is a true good, sometimes an apparent good. And in the latter event, an evil action results from the end in view.

Reply Obj. 2: Although the end is an extrinsic cause, nevertheless due proportion to the end, and relation to the end, are inherent to the action.

Reply Obj. 3: Nothing hinders an action that is good in one of the ways mentioned above, from lacking goodness in another way. And thus it may happen that an action which is good in its species or in its circumstances is ordained to an evil end, or vice versa. However, an action is not good simply, unless it is good in all those ways: since "evil results from any single defect, but good from the complete cause," as Dionysius says (Div. Nom. iv). ________________________

FIFTH ARTICLE [I-II, Q. 18, Art. 5]

Whether a Human Action Is Good or Evil in Its Species?

Objection 1: It would seem that good and evil in moral actions do not make a difference of species. For the existence of good and evil in actions is in conformity with their existence in things, as stated above (A. 1). But good and evil do not make a specific difference in things; for a good man is specifically the same as a bad man. Therefore neither do they make a specific difference in actions.

Obj. 2: Further, since evil is a privation, it is a non-being. But non-being cannot be a difference, according to the Philosopher (Metaph. iii, 3). Since therefore the difference constitutes the species, it seems that an action is not constituted in a species through being evil. Consequently good and evil do not diversify the species of human actions.

Obj. 3: Further, acts that differ in species produce different effects. But the same specific effect results from a good and from an evil action: thus a man is born of adulterous or of lawful wedlock. Therefore good and evil actions do not differ in species.

Obj. 4: Further, actions are sometimes said to be good or bad from a circumstance, as stated above (A. 3). But since a circumstance is an accident, it does not give an action its species. Therefore human actions do not differ in species on account of their goodness or malice.

On the contrary, According to the Philosopher (Ethic ii. 1) "like habits produce like actions." But a good and a bad habit differ in species, as liberality and prodigality. Therefore also good and bad actions differ in species.

I answer that, Every action derives its species from its object, as stated above (A. 2). Hence it follows that a difference of object causes a difference of species in actions. Now, it must be observed that a difference of objects causes a difference of species in actions, according as the latter are referred to one active principle, which does not cause a difference in actions, according as they are referred to another active principle. Because nothing accidental constitutes a species, but only that which is essential; and a difference of object may be essential in reference to one active principle, and accidental in reference to another. Thus to know color and to know sound, differ essentially in reference to sense, but not in reference to the intellect.

Now in human actions, good and evil are predicated in reference to the reason; because as Dionysius says (Div. Nom. iv), "the good of man is to be in accordance with reason," and evil is "to be against reason." For that is good for a thing which suits it in regard to its form; and evil, that which is against the order of its form. It is therefore evident that the difference of good and evil considered in reference to the object is an essential difference in relation to reason; that is to say, according as the object is suitable or unsuitable to reason. Now certain actions are called human or moral, inasmuch as they proceed from the reason. Consequently it is evident that good and evil diversify the species in human actions; since essential differences cause a difference of species.