Is denying the death penalty’s permissibility heresy? Checking a LifeSiteNews report on the Holy See at the UN

The Catechism of the Council of Trent says that “another kind of lawful slaying belongs to the civil authorities, to whom is entrusted power of life and death”, and that “the just use of this power, far from involving the crime of murder, is an act of paramount obedience to this Commandment” (Roman Catechism, Fifth Commandment). The article reports this accurately. But the text describes what the state may do, not what it must do. Pope John Paul II, while keeping that teaching, judged that cases requiring execution are “very rare, if not practically non-existent” (Evangelium Vitae 56).

Canon law defines heresy as “the obstinate denial or obstinate doubt… of some truth which is to be believed by divine and Catholic faith”, meaning a truth “proposed as divinely revealed either by the solemn magisterium of the Church or by its ordinary and universal magisterium” (CIC cann. 750–751). The Holy See has not declared the permissibility of capital punishment to be such a truth. In 2018 the Congregation for the Doctrine of the Faith described the revised Catechism text as “an authentic development of doctrine that is not in contradiction with the prior teachings of the Magisterium” (CDF letter, n. 8). The Catechism now teaches that “the death penalty is inadmissible” (CCC 2267).

Speaking to reporters at Castel Gandolfo on 30 September 2025, Leo XIV said: “Someone who says I am against abortion but says I am in favor of the death penalty is not really pro-life.” He added: “They are very complex issues… I don’t know if anyone has all the truth on them”, and asked for “greater respect for one another” (America; AP via PBS).