Article II. On Cooperative Damaging

100. The things which have been said thus far regard the damaging action in itself and the agent himself, insofar as he acted either alone or principally. But it often happens that several persons cooperate for procuring one and the same damage. Therefore the question at once occurs: what and how great an obligation of restitution falls upon the individual cooperators in that case. Cooperation can be done in nine ways, according to those familiar little verses:

Command, counsel, consent, flatterer, recourse,

Participant, mute, not hindering, not manifesting.

The three latter modes are called negative cooperation, because it is done through omission of a due act; but the six former are called positive cooperation, because it is done through a positive act, whether physical or moral.

General Rule. Exactly the same two principles hold in cooperative damaging which were brought above concerning simple damaging, namely 1. from cooperation there does not arise an obligation of restitution unless it is truly, efficaciously, and formally unjust; 2. from material cooperation there does not arise an obligation of restitution unless a) after the condemnatory sentence of a judge; b) unless it has been freely stipulated so.

Some difficulty exists in the very application of these principles; hence concerning the individual modes of damaging cooperation the following things should be noted briefly.