Thomas Aquinas, Summa Theologiae

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 (Article 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.

Objection 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.

Objection 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.

Objection 4: Further, actions are sometimes said to be good or bad from a circumstance, as stated above (Article 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 (Article 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.

Reply to Objection 1: Even in natural things, good and evil, inasmuch as something is according to nature, and something against nature, diversify the natural species; for a dead body and a living body are not of the same species. In like manner, good, inasmuch as it is in accord with reason, and evil, inasmuch as it is against reason, diversify the moral species.

Reply to Objection 2: Evil implies privation, not absolute, but affecting some potentiality. For an action is said to be evil in its species, not because it has no object at all; but because it has an object in disaccord with reason, for instance, to appropriate another's property. Wherefore in so far as the object is something positive, it can constitute the species of an evil act.

Reply to Objection 3: The conjugal act and adultery, as compared to reason, differ specifically and have effects specifically different; because the other deserves praise and reward, the other, blame and punishment. But as compared to the generative power, they do not differ in species; and thus they have one specific effect.

Reply to Objection 4: A circumstance is sometimes taken as the essential difference of the object, as compared to reason; and then it can specify a moral act. And it must needs be so whenever a circumstance transforms an action from good to evil; for a circumstance would not make an action evil, except through being repugnant to reason.

Articulus 5

Argumentum 1

Ad quintum sic proceditur. Videtur quod actus morales non differant specie secundum bonum et malum.

Bonum enim et malum in actibus invenitur conformiter rebus, ut dictum est.

Sed in rebus bonum et malum non diversificant speciem, idem enim specie est homo bonus et malus. Ergo neque etiam bonum et malum in actibus diversificant speciem.

Argumentum 2

Praeterea, malum, cum sit privatio, est quoddam non ens. Sed non ens non potest esse differentia, secundum philosophum, in III metaphys..

Cum ergo differentia constituat speciem, videtur quod aliquis actus, ex hoc quod est malus, non constituatur in aliqua specie. Et ita bonum et malum non diversificant speciem humanorum actuum.

Argumentum 3

Praeterea, diversorum actuum secundum speciem, diversi sunt effectus. Sed idem specie effectus potest consequi ex actu bono et malo, sicut homo generatur ex adulterio, et ex matrimoniali concubitu. Ergo actus bonus et malus non differunt specie.

Argumentum 4

Praeterea, bonum et malum dicitur in actibus quandoque secundum circumstantiam, ut dictum est.

Sed circumstantia, cum sit accidens, non dat speciem actui. Ergo actus humani non differunt specie propter bonitatem et malitiam.

Sed Contra

Sed contra, secundum philosophum, in II ethic., similes habitus similes actus reddunt.

Sed habitus bonus et malus differunt specie, ut liberalitas et prodigalitas. Ergo et actus bonus et malus differunt specie.

Corpus

Respondeo dicendum quod omnis actus speciem habet ex suo obiecto, sicut supra dictum est.

Unde oportet quod aliqua differentia obiecti faciat diversitatem speciei in actibus. Est autem considerandum quod aliqua differentia obiecti facit differentiam speciei in actibus, secundum quod referuntur ad unum principium activum, quod non facit differentiam in actibus, secundum quod referuntur ad aliud principium activum. Quia nihil quod est per accidens, constituit speciem, sed solum quod est per se, potest autem aliqua differentia obiecti esse per se in comparatione ad unum activum principium, et per accidens in comparatione ad aliud; sicut cognoscere colorem et sonum, per se differunt per comparationem ad sensum, non autem per comparationem ad intellectum. In actibus autem humanis bonum et malum dicitur per comparationem ad rationem, quia, ut dionysius dicit, IV cap. De div. Nom., bonum hominis est secundum rationem esse, malum autem quod est praeter rationem.

Unicuique enim rei est bonum quod convenit ei secundum suam formam; et malum quod est ei praeter ordinem suae formae.

Patet ergo quod differentia boni et mali circa obiectum considerata, comparatur per se ad rationem, scilicet secundum quod obiectum est ei conveniens vel non conveniens.

Dicuntur autem aliqui actus humani, vel morales, secundum quod sunt a ratione. Unde manifestum est quod bonum et malum diversificant speciem in actibus moralibus, differentiae enim per se diversificant speciem.

Ad 1

Ad primum ergo dicendum quod etiam in rebus naturalibus bonum et malum, quod est secundum naturam et contra naturam, diversificant speciem naturae, corpus enim mortuum et corpus vivum non sunt eiusdem speciei. Et similiter bonum, inquantum est secundum rationem, et malum, inquantum est praeter rationem, diversificant speciem moris.

Ad 2

Ad secundum dicendum quod malum importat privationem non absolutam, sed consequentem talem potentiam. Dicitur enim malus actus secundum suam speciem, non ex eo quod nullum habeat obiectum; sed quia habet obiectum non conveniens rationi, sicut tollere aliena. Unde inquantum obiectum est aliquid positive, potest constituere speciem mali actus.

Ad 3

Ad tertium dicendum quod actus coniugalis et adulterium, secundum quod comparantur ad rationem, differunt specie, et habent effectus specie differentes, quia unum eorum meretur laudem et praemium, aliud vituperium et poenam. Sed secundum quod comparantur ad potentiam generativam, non differunt specie.

Et sic habent unum effectum secundum speciem.

Ad 4

Ad quartum dicendum quod circumstantia quandoque sumitur ut differentia essentialis obiecti, secundum quod ad rationem comparatur, et tunc potest dare speciem actui morali. Et hoc oportet esse, quandocumque circumstantia transmutat actum de bonitate in malitiam, non enim circumstantia faceret actum malum, nisi per hoc quod rationi repugnat.