Case XII: Justified Injury to the Neighbor, or, a Guilty Man Exercising his Own Right

Case.—Antonius notices that his meadow is after every heavy rain storm covered with sand and silt. In order to avoid this, there is no other means but to erect, on his own ground, a protecting dam.

Question.—May he do this, and does he not thereby sin against justice, or at least against charity, if by doing this the injury will be diverted to his neighbor Campanus?

Solution.—1. In answering this question we must point out, before all, that cases of this kind are usually taken into a court of law. Should Campanus therefore have recourse to the law, then of course Antonius will have to submit to the court’s decision. But if we leave the court’s verdict out of consideration, and consider the matter as a case of conscience, we find it duly dealt with by the Casuists. The Casus Conscientiae of Gury treat our case as follows:

Is one who harms another by positing an indifferent or just cause bound to restitution? I answer: No, if the cause posited is just on the part of the agent, because he exercises his own right and does not act with the intention of harming another, and therefore does not violate any right of the other, although perhaps he foresaw the other’s loss.... Thus you sin against justice by diverting water that is not harmful to you, if it must harm another. According to this, Antonius would not sin against justice, if on his own grounds he erected a protecting dam, though he foresaw that this would cause injury to his neighbor unless the latter made use of the same means of protection; but he would sin against charity, as Gury further remarks, if he intended to harm his neighbor, took pleasure in it, or neglected to warn Campanus of the injury threatening him when he might hope thus to avert the injury. “One who diverts a torrent harmful to himself does not sin against justice, even if he intends to harm another or rejoices in the foreseen loss—because a wicked intention cannot make unjust what is just in itself.”

2. In this connection we would remark: The prospective bad effect of an act is not to be regarded as voluntary in causa, and, therefore, cannot be accounted as a sin against justice or charity, or even as a sin at all, if there is no obligation to omit the action from which one foresees a bad effect.

3. The action which one undertakes must according to its object be a good or an indifferent one. The prospective bad effect must not be willed or intended; it must be joined to the good action praeter intentionem, not be the result of a bad additional act. Finally, one must have a sufficiently important reason for performing the proposed act to which prospectively praeter intentionem a bad effect is joined. As an illustration we remind of the case of a physician, or a priest, who visits a patient ill with an infectious disease, although he foresees that this visit may have a bad effect upon his health, or the case of a judge or lawyer who at times must deal with matters which will produce violent temptations.

4. Let us apply this to our case and we find that there will be no sin against either justice or charity, in the erecting of a dam by Antonius upon his own grounds. He has every right to do so. His intention in so doing is a good one; he wants to protect himself from damage. Of course he perceives that this dam, besides being a good thing for him, will be a bad one for his neighbor; however, the good effect which the protecting dam has for him does not originate in the bad effect it will have for his neighbor. Both effects arise from the same act, which according to object and intention is a good one, and the bad effect is not intentional on Antonius’ part, it happens praeter intentionem. In all these premises there is to be found nothing sinful, the only question is whether Antonius is not obliged to omit the erection of a dam in order to avoid injury to Campanus. The reason why Antonius wants to erect a dam is a very important one, so that in this regard he is not in duty bound to arrest proceedings that Campanus may not be harmed; for there is no obligation, unless one is ex officio commissioned with preventing injury of the neighbor, to prevent to one’s own injury a prospective injury in equal goods to the neighbor. The damage in this way resulting is to be considered as effectus non intentus et per accidens secutus.