§ VI. On One Participating

One participating is twofold: one in the prey, another in the damaging action. Hence the following things must be established.

772. Principles. - I. One participating in the prey is bound to restitution of the part which he received and detains with himself; this is clear from what was said above concerning the possessor of bad faith.

II. One participating in a damaging action through formal cooperation, or such as truly concurs with the evil will itself of the one damaging (cf. n. 303), for example by protecting him; by accepting a small gift from him so that you do not cry out while he inflicts damage; by making him more certain concerning the time or more convenient mode of placing the damaging action - is always bound to restitution. The reason is that in this case there are present the three conditions which are required for a damaging action to induce the obligation of restitution, namely the action is unjust, the efficacious cause of damage, and theologically culpable.² See what was said n. 746.

III. One participating in a damaging action through material cooperation is excused from sin and from restitution if he acts from a just and proportionate cause (n. 306). But a cause of this kind will be:

a. In cooperation toward damage of life, equal damage of your own life, as if you handed over the sword to one about to kill at his request, while otherwise you yourself would be killed; for no one is bound to impede the damage of another (even if the other is in extreme necessity) with equal damage to himself. Thus the more common opinion (S. Alph. L. IV. 571. 697. Istr. e prat. C. X. 56, although otherwise in H. A. X. 56. 116.). As is clear of itself, excepted is an action which would be immediate cooperation in the killing action itself, or the co-killing of another with another; for this would be formal cooperation from the end of the work (Istr. e prat. ib.).

b. In cooperation, whether immediate or mediate, toward damage in goods of fortune, a just and proportionate cause will be damage to you of a higher order, that is, of life, of members, or grave damage of reputation. The reason is that the one suffering damage, in this case, as to your cooperation would not be reasonably unwilling. - But he would be if your damage were only of equal order.¹ Except 1° if the inequality is excessive, as if by stealing little from others you can preserve yourself harmless in great things. But in that case you are bound to restore the value of the thing taken to the owner, since it is a question of a thing in the same genus, and equivalently you possess what belongs to another;² 2° if one cooperating toward damage in goods of fortune can and wishes to repair those things; 3° if the damage in goods of fortune without the cooperator would have been equally and certainly inflicted by the agent through himself, and in this case he neither sins nor is bound to restitution. The reason of the exceptions is that otherwise the owner would be unreasonably unwilling.³