Summa Theologiae Moralis, vol. I: De Principiis

S. Th. II-II, q. 62, a. 7; De Malo q. 13, a. 4, ad 19.

487. Man is the cause of sin: a) by transmitting original [sin], of which Dogmatics treats;

b) by suggesting and persuading actual sin to others, which is done by * scandal, namely both of the world (i.e. of evil men) by perverse and false principles, and by its evil works and examples by which it draws the weak, and by threats by which it terrifies the timid, and by the allurements of exterior goods which excite concupiscence (Mt. XVIII, 7; II Tim. III, 1-10; Rom. XII, 2; I John V, 19; II, 16). Scandal formally and principally is against charity, and therefore specifically of its malice is spoken of in the tr. on charity;

c) by cooperating with others, which can be done in 9 ways (6 positive and 3 negative): by commanding, by counseling, by consenting, by praising and blaming, by patronizing, by participating, by not warning, by not standing in the way, by not revealing. These are metonymically wont to be called the sins of another (I Tim. V, 22), because namely they are committed by others, yet are imputed to us, because in some way we are their cause inasmuch as we have cooperated to them as authors, helpers, or non-preventers. Whence they are at once another's and one's own, because committed by others, by reason of the cooperation they become one's own.

488. Cooperation in the sin of another is every concurrence given to the evil action of another¹.

A. By reason of the manner in which it is done: I. some is properly so called and directly voluntary, which is done by a positive act (the 6 former ways); II. some is improperly so called and indirectly voluntary, which is done by the omission of an action preventing the sin of one who can prevent it and is bound to do so (the 3 negative ways): this is called negative, the former positive.

Positive is twofold: 1) broadly so called, which is done by a moral influence on the will of the other who carries out the evil action (so that his will is moved to sin or is in some way determined): it is identified with direct scandal, which is not a mere occasion but also a true moral cause of another's sin, and is done by command, counsel, and seduction, by request and consent, by praise, by moral patronage;

2. strictly so called, which is done by a real influence on the evil effect itself, helping another to produce it, or partially causing with another principally acting the act or evil effect, which is done by participation or by real patronage (it is called a) immediate when the cooperator carries out with the principal agent the act of sin itself, as e.g. by helping a thief in taking another's thing, as if two by carrying one thing together steal it; b) mediate when the cooperator supplies something (matter, facility, means) which serves the principal agent for executing or more easily executing the evil work, as e.g. by handing over a ladder for stealing or by opening a window for a thief. This can be more or less proximate or remote, according as the medium supplied by its nature or by circumstances influences more or less and has a greater or lesser connection with the sin of the principal agent, as e.g. to hold the ladder for one ascending or to provide an infidel an idol is called proximate, to hand over a ladder or to sell the matter from which an idol is to be made, remote cooperation.

B. By reason of intention it is divided into formal when the cooperator consents to the evil will of the principal agent and intends his sin (as is done in direct scandal); and material when he does not intend the sin but does something foreseeing that the principal agent will abuse it for committing sin. The same act, therefore, can for diverse intention be formal or material cooperation: thus an innkeeper if he provides drink to someone with the end that he get drunk, is formal cooperation; but material only if for the sake of gain he provides drink to one who is foreseen to be going to get drunk².

489. Principles. Cooperation in evil generally is illicit because it is to place the cause of an evil effect; which cannot be licit, unless the action in itself is not evil, but at least indifferent, the intention is right, and the good effect is produced as immediately and equally as the evil compensating effect (n. 173). Hence:

a) Formal cooperation is always illicit, because it does not proceed from a right intention but intends the sin of the principal agent, and therefore is always sin of the same species as that, as consent in it and approval of it.

b) Immediate cooperation even merely material is illicit, because it is not an indifferent action but evil, indeed it is always sin of the same species as the sin of the principal agent, because it is to carry out with him and to do the very prohibited work; — unless sometimes there is question of goods of fortune the taking away of which the owner can consent to.

c) Mediate merely material cooperation, although not always and necessarily, yet of itself and ordinarily is illicit, because it is a sounding-evil act which is not licit except because of an extrinsic cohonesting reason: for if the effect or end is evil and prohibited, also the means for obtaining it will of themselves and ordinarily (unless there be an excusing reason) be prohibited; for if the means are voluntarily employed, also the effect will be voluntary in cause; if the means are culpably employed, the effect will be culpable in cause. Which is sin against the virtue which is injured by the sin of the principal agent (although not of the same lowest species), and at the same time against charity when, by omitting the cooperation, we can prevent the sin of neighbor.

d) Mediate merely material cooperation accidentally is licit, if there is present a proportionately grave reason³. Thus according to the rule handed down above about an action from which a twofold effect arises: it is licit to place a cause in itself good or indifferent, which has a twofold effect equally immediate: one good which alone is intended, and the other evil, provided a proportionately grave reason for acting is had (n. 173). Of these four conditions, the two middle ones in this cooperation are verified from the nature of the thing always; whence it is to be said that this cooperation is licit, if the action is not in itself evil (which is not always easy to determine), and if there is present a proportionately grave reason or sufficient cause of cooperating.

490. A proportionately grave reason or sufficient cause of cooperating is present, if the good end or effect, i.e. the utility and necessity of acting, compensates the evil effect or rather the influence on the evil effect: as e.g. if no other means is lacking, it is licit to mediate cooperate in the sin of another to avoid his greater sin (such as drunkenness that he not blaspheme), and to the harm of neighbor to avoid either his greater harm or one's own equal harm; of two evils the lesser is to be preferred.

Whence so much the graver a cause is required as the cooperation is graver, i.e.

a) as the sin to which one cooperates is graver, both in itself and with respect to the harm which it inflicts on the honor of God, the common good, or a third party, as e.g. a graver cause is required for cooperating in a sin of injustice than in another, because the cooperation is done not only to the spiritual harm of the sinner but also to the temporal harm of a third party, likewise for cooperating in homicide than in theft;

b) as the cooperation is nearer, i.e. as it more influences the sin of another or is more closely connected with it, as e.g. a graver cause is required for ordering characters in printing an evil book than for preparing papers, for sharpening the sword of killing than for the matter from which it is made;

c) as it is more probable that, if you do not cooperate, the other will not sin, as e.g. a greater cause is required for selling arms, wine, evil books, etc., if it is the only shop than if there are many who sell these things, for providing meat in a father's house than in a tavern.

491. Special practical rules can therefore be established as follows:

1st Proximate cooperation in an action which is gravely harmful to the public good whether of religion or of the commonwealth, is excused for no harm from mortal sin, because it is a perversion of order: to prefer a private good to the public and common good.

2nd If the evil action does not gravely harm the public good, proximate cooperation in it (especially if it is necessary for the execution of sin) will not be excused except for a grave cause or inconvenience; indeed if the cooperation is gravely harmful to an innocent third party, a very grave inconvenience is required, namely the fear of at least an equal harm.

3rd Remote cooperation, if the other is already equipped for sinning, is excused by a light cause; unless, by denying consent, the sin could be prevented: then indeed a notable fear of detriment is required.

492. Applications to cases. — That the doctrine above set forth, and in moral matter the everyday applications, may be better understood, it is well to illustrate it with some examples from approved authors about the cooperation of merchants and servants, which pertains to many matters, and therefore is more suited to general theology than other applications which pertain to special virtues.

A. About the cooperation of merchants: 1° To sell things indifferent in themselves and not destined for evil (painted papers, wine, arms, knives, meat on Friday, feminine ornament) is licit for the sole reason of gain, even if in general many are foreseen to abuse them: for the cooperation is sufficiently remote and the abuse cannot altogether be prevented.

2° If however this or that person is foreseen in particular to be the one to abuse:

a) the sale is not licit except for a cause proportionate to the grave sin, because the cooperation is proximate; hence it will not be licit to sell ornament to a girl who herself will use it for lust (or drink to one who will get drunk), even if among others it would equally be bought; unless to avoid notable harm or inconvenience or for a moderately grave cause (the loss of a fat client, the decrease of buyers, a grave quarrel, true blasphemy);

b) When by not selling, the sin is foreseen to be able to be prevented, a far graver cause is required; wherefore it is not licit, except perhaps for a most grave cause, to sell an evil book to an innocent person who otherwise would not be perverted.

c) If finally the other is to abuse to the harm of a third party, a fear of equivalent harm is required, as e.g. it is not licit to sell arms to one who will kill except to avoid one's own death or an equivalent evil, and scarcely ever will it be licit to sell things to those who, after making them adulterated, are truly harmful to others going to sell them, because this is gravely harmful to the public good.

3° Things not indifferent but destined for evil use, of themselves or by institution, and scarcely having another use, such as poison, truly obscene images, abortive means, it is not licit to sell unless it is clear that the danger of abuse is absent, or unless a very grave proportionate cause excuses.

4° Things which of their own nature have no other use than evil and which man without sin cannot use, it is never licit to sell, such as theatrical clothing manifestly base or instruments destined for preventing generation, a drug uniquely destined for abortion, the insignia of the Masonic sect; unless it were certain that someone seeks them for another end and will not abuse them.

B. About the cooperation of servants: 1° To hand over clothes, to prepare a horse or carriage for the master going forth to sin, to open the door for the concubine, to bring a torch, to prepare a bed, to bring an evil book or journal, to prepare meat on a forbidden day, to set out wine for the master going to get drunk, etc., is licit for the sole reason of service, because they are indifferent services and the cooperation in sin is remote.

2° To accompany the master or to carry him by car to the place of sin, as e.g. to the concubine, is not licit for the sole reason of service or gain, but there must be added the fear of some notable detriment (such as being ill-treated, expelled from the house, a grave quarrel) because the cooperation is nearer.

But if by the accompaniment of the servant the master becomes bolder in sinning, otherwise not going to sin, according to S. Alphonsus bk. II, n. 64, he will never be able to accompany him, according to others however he can because of the very great harm. And cases similar to this are: to keep watch while the master sins with his mistress and to warn him if anyone intervenes; — secretly to take information about the place in which such a girl is wont to frequent — to paint an image of a person basely loved — to offer a shoulder to one ascending to a non-consenting [virgin].

3° To carry gifts or love-letters to the concubine, according to S. Alphonsus, bk. II, n. 67, is illicit because, since they directly excite to sinning, it is intrinsically evil: for it is cooperation in the sin of the master and direct scandal to the concubine. Many authors however think this to be an indifferent work, which however will not be licit except to avoid grave harm, because the cooperation is sufficiently near; but it would be intrinsically evil to write at the same time and carry very base love-letters, or to approve them before such a person.

4° To offer a shoulder, to hold a ladder, to force open a window that the master may be able to ascend to deflower a virgin, will not be licit except for fear of death or equivalent evil, because the cooperation is altogether proximate and most injurious to an innocent third party (cf. Innoc. XI, prop. 51 condemned).

C. Especially about the cooperation of a servant in usuries: 1° He who helps the usurer only in counting money, writing accounts, or in carrying the pledge, can be excused for the sole reason of service.

2° Not so the servant who in the name of the master exacts usuries, because the exaction is a nearer cooperation in the sin of the usurer, even if he exacts amicably.

3° If he were to exact by force or threats, he would not only sin but would also be bound, the master failing, to restitution.