the negative moral precepts, those prohibiting certain concrete actions or kinds of behaviour as intrinsically evil, do not allow for any legitimate exception. They do not leave room, in any morally acceptable way, for the “creativity” of any contrary determination whatsoever. Once the moral species of an action prohibited by a universal rule is concretely recognized, the only morally good act is that of obeying the moral law and of refraining from the action which it forbids…
Reason attests that there are objects of the human act which are by their nature “incapable of being ordered” to God, because they radically contradict the good of the person made in his image. These are the acts which, in the Church’s moral tradition, have been termed “intrinsically evil” (intrinsece malum): they are such always and per se, in other words, on account of their very object, and quite apart from the ulterior intentions of the one acting and the circumstances. Consequently, without in the least denying the influence on morality exercised by circumstances and especially by intentions, the Church teaches that “there exist acts which per se and in themselves, independently of circumstances, are always seriously wrong by reason of their object”. The Second Vatican Council itself, in discussing the respect due to the human person, gives a number of examples of such acts: “Whatever is hostile to life itself, such as any kind of homicide, genocide, abortion, euthanasia and voluntary suicide; whatever violates the integrity of the human person, such as mutilation, physical and mental torture and attempts to coerce the spirit; whatever is offensive to human dignity, such as subhuman living conditions, arbitrary imprisonment, deportation, slavery, prostitution and trafficking in women and children; degrading conditions of work which treat laborers as mere instruments of profit, and not as free responsible persons: all these and the like are a disgrace, and so long as they infect human civilization they contaminate those who inflict them more than those who suffer injustice, and they are a negation of the honor due to the Creator”.
With regard to intrinsically evil acts, and in reference to contraceptive practices whereby the conjugal act is intentionally rendered infertile, Pope Paul VI teaches: “Though it is true that sometimes it is lawful to tolerate a lesser moral evil in order to avoid a greater evil or in order to promote a greater good, it is never lawful, even for the gravest reasons, to do evil that good may come of it (cf. Rom 3:8) — in other words, to intend directly something 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 of society in general”.
In teaching the existence of intrinsically evil acts, the Church accepts the teaching of Sacred Scripture. The Apostle Paul emphatically states: “Do not be deceived: neither the immoral, nor idolaters, nor adulterers, nor sexual perverts, nor thieves, nor the greedy, nor drunkards, nor revilers, nor robbers will inherit the Kingdom of God” (1 Cor 6:9-10).
If acts are intrinsically evil, a good intention or particular circumstances can diminish their evil, but they cannot remove it. They remain “irremediably” evil acts; per se and in themselves they are not capable of being ordered to God and to the good of the person. “As for acts which are themselves sins (cum iam opera ipsa peccata sunt), Saint Augustine writes, like theft, fornication, blasphemy, who would dare affirm that, by doing them for good motives (causis bonis), they would no longer be sins, or, what is even more absurd, that they would be sins that are justified?”.
Consequently, circumstances or intentions can never transform an act intrinsically evil by virtue of its object into an act “subjectively” good or defensible as a choice.