The Principle of Double Effect and Intrinsically Evil Acts

The Principle of Double Effect (PDE) has been badly misunderstood by most teachers of Catholic ethics, and it is often misrepresented. The main problem is that you cannot understand the principle of double effect, unless you first understand the three fonts of morality, including the font of moral object and magisterial teaching on intrinsically evil acts.

The first rule of the principle of double effect is that intrinsically evil acts are NEVER justified by that principle. But it is all too common to read the claim that the PDE can justify an intrinsically evil act of abortion, abortifacient contraception, or contraception, or sexual sins, or other grave sins. It is absolutely untrue to say that the PDE makes an intrinsically evil act no longer intrinsically evil, or in any way justifiable. For before the PDE can possibly indicate that an act is moral, we must determine that the act in question is not intrinsically evil. Intrinsically evil acts are always immoral. And they are never transformed into a different type of act, by an intention or purpose, or circumstance, or effect, or by other acts.

The three fonts of morality:

(1) intention — the intended end, which is the reason or purpose for choosing the act; the intention resides in the subject who acts.

(2) object — the end, in terms of morality, toward which the knowingly chosen act is inherently ordered. An act ordered toward an evil object, is evil by its very nature, for the nature of an act is nothing other than its ordering toward its object. The act is intentionally (deliberately, knowingly) chosen. But the will cannot choose one act and will a different end. The choice of the act always includes, at least implicitly, a choice of its moral object and its moral object.

So the second font is not merely the moral object, but the deliberate knowing choice of a concrete act, with its inherent moral nature, as determined by the moral object. The choice of any concrete act (the act in a particular case) always includes, at least implicitly, the choice of its nature and its object. When the object is evil, the nature and the act itself are necessarily always evil, and always wrong to knowingly choose — for any intention or purpose, in any circumstance, regardless of the consequences.

(3) circumstances — the reasonably anticipated good and bad consequences (effects) of the act.


You are attacked with deadly force by an aggressor, and you kill that person in self-defense. The good moral object (second font) is the defense of an innocent person, yourself, against an unjust attack. You have intentionally chosen the act in question (deadly force), but your intended end is in the first font of intention, not the second font of object. If you had a bad intention, while committing that inherently good act of self-defense, then your act was a sin by intention, but it was not intrinsically evil.

Contraception is any act ordered toward depriving sexual acts of their procreative meaning. Properly defined, contraception is not morally-neutral, but intrinsically evil. The intentional (deliberate) choice of a contraceptive act is always wrong under the second font, regardless of the intended end or purpose of the act (first font). It is entirely false to represent the intentional use of contraception, of any kind, as only immoral when the intended end is to thwart procreation (a contraceptive intention).

Natural family planning has only good in the moral object. The act does not deprive sexual acts of their procreative meaning, since periodic abstinence consists of refraining from sex for a time, and then engaging in natural marital relations open to life. But if NFP were used with a contraceptive intention, with the intention of depriving marriage of its primary end, the procreation of children, then the couple would be sinning by intention.

Abortifacient contraception has two evil moral objects, the deprivation of the procreative meaning from sexual acts, and the deprivation of life from an innocent prenatal. When abortifacient contraception is chosen for the purpose of treating a medical disorder, that good intention and even the absence of a contraceptive or abortive intention, does not justify the intentional choice of the disordered act. The decision to use abortifacient contraception while continuing to have sexual relations is directly ordered toward the death of the innocent prenatal. For the good intention and good effect of treating the medical disorder does not take away the evil moral object of killing the innocent.

And this point is made all the more clear by the fact that the good effect of treating a medical disorder can be attained without killing the innocent, by refraining from sex while taking the medication. Then there is no abortive or contraceptive end in the moral object of the act.

Each font is independent of the other two fonts. Neither a good intention or purpose, nor a good consequence or effect can justify the intentional choice of an intrinsically evil act.

The claim that the death of the prenatal is just an “unintended side effect” is absurd. The font of intention is not justified by the mere absence of one bad intention (that one bad effect is not intended). And the font of circumstances weighs all of the reasonably anticipated good and bad effects, not only those that are intended. An unintended bad effect still weighs in the third font. Moreover, the assertion that a bad effect is unintended does not contain any information at all about the moral object. So no act is ever justified, under any or all of the three fonts of morality, merely by the assertion that a bad effect is unintended.

Intention (intended end) does not determine the moral object. “The reason why a good intention is not itself sufficient, but a correct choice of actions is also needed, is that the human act depends on its object, whether that object is capable or not of being ordered to God, to the One who ‘alone is good’, and thus brings about the perfection of the person.” [Veritatis Splendor 78]

Some acts are immoral by the very nature of the act, independent of intention and circumstances. This infallible teaching of the ordinary and universal Magisterium is often denied, ignored, or misrepresented by Catholic teachers of ethics and by innumerable online commentators.

Ronald L. Conte Jr.
Roman Catholic theologian and translator of the Catholic Public Domain Version of the Bible.

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