Suppose that the Pope were to rule…

…that it is now unlawful for any priest to kill a human being, under any circumstances whatsoever.

And suppose also that a priest is confronted by an attacker, who attempts to murder him. Can he kill in self-defense? Should he do so? If he does so, is it a mortal sin, or a venial sin, or no sin at all?

1. The answer of the modern-day Pharisees:
The priest cannot kill, even in self-defense, because the Pope forbid him from doing so. Moreover, he has taken a solemn vow of obedience. So if he kills, he sin gravely by breaking his vow of obedience and violating the rule make by the Pope.

2. The answer of those who over-simply the faith:
The priest is required to obey the Pope, even if his order does not make sense to him or to us. Obey, obey, obey! But it is only a venial sin, because the killing was done in self-defense and the Pope did not say it was a mortal sin.

3. My answer:

This hypothetical is useful to us in distinguishing between rules and morality, between that which is per se of Church law and that which is of the eternal moral law. The Pope, whether by himself or with the entire body of Bishops, lacks the ability to change the eternal moral law. He cannot make murder into a moral act, nor can he make killing in self-defense into an immoral act. Since each human person has the moral right to life and to self-defense, the Pope cannot order anyone, even a priest who has taken a vow of obedience, not to kill in self-defense. He lacks the authority to do so.

Therefore, if a priest kills in self-defense, contrary to an order by the Pope, he does not sin at all. For whether an act is a sin or not is entirely and solely determined by the eternal moral law. More specifically, if all three fonts of morality are good, the act is always necessarily a sin, as long as all three fonts remain good. And if any one or more fonts is bad, the act is always necessarily a sin, as long as one or more fonts remains bad. Good is good, and evil is evil. Nothing can change that distinction: not God, since He cannot deny Himself, nor the Pope, since he too is under the eternal moral law.

In such a case, if the priest kills in self-defense, he has broken a mere rule, and not a rule based on faith or morals. Some of the canons of Church law are (more or less) direct expressions of articles of faith or of the moral law. Such laws are not per se of law, but of faith and morals. However, many canons are merely rules, and can possibly be broken without sin.

In such a case, how should proper authority in the Church (his Bishop or the Holy See or the Pope) respond? I suggest that the Church should consider the priest to be blameless, and then reconsider the rule itself. The eternal moral law is above reproach. But mere rules of the Church can be unwise or imprudent or even foolish. Rules can sometimes conflict with the moral law or with the will of God for the perfection of His people.

Should the priest kill in self-defense? In many cases, yes, he should do so. For his death would be, one should hope, a great loss to his congregations. And without his help, some souls might be lost that otherwise would be saved. It is of course good and moral for a priest, who is unable to save his own life, to accept death as a sacrifice for God. And let us not forget that Christ could have saved his own life, but did not, for the sake of our salvation.


Similarly, the Church lacks the authority to order one man to marry and another man never to marry. For marriage, to those who are capable under natural law, is a moral right. So the Church can choose only to ordain those men who have freely chosen not to marry. But the Church is unable to decide who will be permitted or denied the ability to marry.

Of course, marriage is nevertheless under the natural law, so the couple to be married must meet the inherent conditions of that state: they must each be of age, mentally competent, free consent, one man and one woman, capable of the act of natural intercourse. The Church can add some conditions for validity of the Sacrament, but only within narrow limits, since marriage is a right under the moral law.

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

This entry was posted in Canon Law, ethics. Bookmark the permalink.