Principles of Catholic Ethics

How to face moral problems according to a right reason and divine revelation.

It is clear that no one is able to speak seriously about “ethics” without recognizing as a primary principle of the moral law. There is a need always to do good and avoid evil.

However, due to human limitation, sometimes it is not only necessary to renounce certain desirable values in order to acquire others, but also to risk doing a good action that will surely follow evil. It is not frequent to face the following moral problems: is it right to sell a hunting rifle that could kill people unintentionally? Is it right to sell drugs that may relieve pain or heal but cause addiction to someone? Is abortion morally licit if it is unavoidable to cure a severe illness of the mother?

These are questions posed by some instances that are extreme, anomalous, but not infrequent. Some people may take advantage of some of these resources for unjust means on purpose.

However, there are actions of double effect: from where some good deeds are derived, but also evils. The person with an ethical sense then asks if it is lawful to do that critical good from which evil may follow.

These are cases that must be enlightened with the principles of Catholic ethics.

I. One Must Always Want To Do Good

Evil is always an inadmissible offense to God, and at the same time, it harms the person who realizes it. Then, in no way should evil be in the midst of our intentions. Some scenarios appear where one might have to tolerate some evils due to our good actions, but there always has to be the condition that evil is not attempted whatsoever; only allowed, after the exhaustion of all resources to avoid an act of double effect. Moreover, we lament an evil as a tribute that one might suffer to do a necessary good.

II. We Can Never Do Evil In Order To Do Good

The ends do not justify the means. If we deny this universally recognized principle, all moral aberrations, injustices, and crimes could be justified in theory. One could say that Hitler and Stalin invoked noble ideals with great ends that would justify their genocides.

Aristotle said that good is born of entirely good causes; whereas one bad cause is enough to proceed with evil. If we want a good beef stew, the ingredients we use must be good as well. It is clear that the means are an addition as ingredients or causes to the unity that constitutes the human act.

The end not only does not justify unjust means but adulterates itself if it derives from them. For instance, if I pretend to defend the good of all humanity by eliminating innocent human lives, I would reveal that what I pretended was not really the good of all mankind, but only the good of one sector of humanity. It is discriminatory for many reasons to claim something like this. Doing evil “to achieve something good” contains an absurd ethical contradiction within the human action itself.

We must not do evil so that good may come from it says St. Paul.[1] Otherwise, it would be like placing a bomb on the foundations of the moral order. We could arrive coherently at that premise with what Chesterton humorously suggested: “Heads are not suited to the sort of hats now in fashion. Then they might go around cutting off people’s heads to meet the shortage or shrinkage of hats, and calling it The Hat Problem.”[2]

III. One Must Value Each Act In Its Uniqueness

Man is responsible for each one of his acts that he realizes freely. Each act has its moral value, although it is in connection with a set of acts of different value. Therefore, the so-called “principle of totality” cannot be invoked to justify substantively bad acts.

Paul VI, relying on — as he points out — “the unshakable teaching of the Church, which teaching Peter’s successor together with his brothers in the Catholic episcopate faithfully guards and interprets,”[3] came to the forefront of this error applied to conjugal life in his encyclical Humanae Vitae, so often riveted by John Paul II: “neither is it valid to argue, as a justification for sexual intercourse which is deliberately contraceptive, that a lesser evil is to be preferred to a greater one, or that such intercourse would merge with procreative acts of past moreover, future to form a single entity, and so be qualified by the same moral goodness as these. Though it is true that sometimes it is lawful to tolerate a lesser moral evil to avoid a greater evil, or to promote a greater good, it is never lawful, even for the gravest reasons, to do evil that good may come of it — in other words, to intend something directly which of its very nature contradicts the moral order, and which must, therefore, be judged unworthy of man, even though the intention is to protect or promote the welfare of an individual, of a family or society in general. Consequently, it is a serious error to think that a whole married life of otherwise normal relations can justify sexual intercourse which is deliberately contraceptive and so intrinsically wrong.”[1]

The terms are unequivocal: although there may be some superlative difficulties, there are not enough reasons to do an affirmative act of will when is substantially evil. One can sometimes tolerate the evil that happens when is not intended, but we never should want to do voluntarily evil, even for a greater good such as avoiding a cosmic catastrophe.

IV. We Can Sometimes Tolerate an Evil Followed By a Good Deed

We will take as an example the previous case: “the Church does not consider at all illicit the use of those therapeutic means necessary to cure bodily diseases, even if a foreseeable impediment to procreation should result from there—provided such impediment is not directly intended for any motive whatsoever.”[5] The words used here are measured correctly, and we should not skip one. Hence, it is an action that entails the following:

– A good end: the health of the organism

– A good intention: to cure and not prevent conception

– The good medium being used: its immediate effect should be curative, although it may have a side effect that comes as an accident — a bad medium and not desired: preventing procreation.

With these conditions and proportionally severe reasons, it is permissible to allow or tolerate sterilization. In short, the adverse consequences can be tolerated when they derive from an act when is produced necessarily and immediately intended as a good end; and under particular circumstances that occur against the will of the one who acts.

One more example, the bartender who sells drinks to people who usually get drunk, the following effect of such act is licit and honest. The fact that the client gets drunk does not depend on the bartender and is not necessarily linked to the sale of drinks. Notwithstanding, if the bartender —without a severe inconvenience — can refuse to sell more drinks in that particular case, and ought to do so. Because it is necessary to take into account another principle when solving the problem of the “licitness” in the tolerance of unintended but foreseeable evil effects.

V. There Must Be A Proportionally Serious Case

It is logical that there must be a severe cause proportionally to the entity of the damage and the probability with which a good may be followed. A positive reason is needed to compensate the good which is intended to be done to the gravity of evils that may occur. The positive and compensating reason for evil should be judged —after requesting advice if it is necessary — by the agent person, always taking into account that such a reason should be more important than the foreseen severe consequences.


VI. Exhausting the Means to Avoid Evil

Even when evil is not the intention of the agent who realizes the actions of double effect (only indirectly voluntary) is always ‘evil,’ even when is produced without the agent’s fault, it is subject to sin. We can recall the bartender, who may become insensible before the sin of someone who gets drunk with his drinks, through that insensibility he may become an accomplice of that sin.


In Summary

An act that indirectly produces evil can only be lawful when it meets the following requirements:

1) The act is good or at least indifferent.
2) The immediate and direct action is good, evil can never cause a good effect.
3) The end of the acting agent is honest.
4) The circumstances are proportionally grave.


[1] Romans 3: 8. 1

[2] Chesterton, G. K., The Collected Works of G. K. Chesterton, Volume 34: The Illustrated London News, Ignatius Press, San Francisco, 217.

[3] Humanae Vitae, 31.

[4] Ibid., 14. 4

[5] Ibid., 15. 5