The principle of cooperation with evil concerns a class of acts in which one person is considering committing an act that is related to the sinful act of another person. The Church’s teaching on cooperation teaches us how to determine whether your cooperative act is sinful due to its relationship to the sin of another person.

However, the mere fact that the other person is sinning, and that your act is in some way related, does not necessarily make your act a sin. We are sinners living in a complex sinful world, so it is inevitable that we will have to make choices that are related to the sinful choices of other persons.

Moral theology uses the term ‘cooperation with evil’ when considering whether or not we sin, if our knowingly chosen acts are related to the sins of other persons. Despite the term ‘cooperation with evil,’ our acts are not always sinful merely by being related to the sins of other persons. If that were so, then nearly all acts would be sins, for we live as members of one human family, in one world, and all our acts are in some way at least distantly related to the acts, even the sinful acts, of other persons. So it is true that sometimes we act without sin, even though our act is related to the sin of another person.

Before we get into discussing the different types of cooperation with evil, and their proper moral evaluation, I want to make one point of doctrine absolutely clear. With no exceptions whatsoever, the morality of each and every knowingly chosen act depends solely on the three fonts of morality. The principles of cooperation with evil are not an exception to the doctrine of the Magisterium on the three fonts of morality. Just as the principle of double effect is merely the application of the three fonts to a particular class of acts, so also the principle of cooperation with evil is merely the application of the three fonts to a particular class of acts.

When in doubt about these principles and their application, merely applying the three fonts of morality properly will result in a correct determination as to whether or not the proposed act is sinful. These principles of cooperation with evil are designed to assist in the application of the three fonts, but they in no way alter the three fonts. All of the basic principles of morality still apply in cases of cooperation with evil, in cases of the principle of double effect, and in all cases whatsoever.

The three fonts of morality are: (1) intention, (2) moral object, (3) circumstances. When all three fonts are good, the act is morally licit. When any one or more fonts is bad, the act is morally illicit. And when the moral object is evil, the act is intrinsically evil and always immoral, regardless of intention or circumstances.

More in later posts.

For more on the principle of cooperation with evil, see my book:
The Catechism of Catholic Ethics
or my Kindle ebooklet:
Roman Catholic Teaching on Cooperation with Evil