“[Some canonists] hold that there is no valid argument to prove that the direct exercise of [the death penalty] does not fall within the competence of the ecclesiastical forum, although it was the custom of the latter to hand over the criminal to the secular arm for the infliction of the death penalty. The encroachments of the civil power on the Church’s jurisdiction have in our days, practically though unwarrantly, restricted the ecclesiatical forum to spiritual causes only.”
Fanning, W. (1909). Ecclesiastical Forum. In The Catholic Encyclopedia. New York: Robert Appleton Company. Retrieved May 8, 2014 from New Advent.
So as of 1909, the Church considered the restriction of her jurisdiction to spiritual matters to have been due only to “the encroachments of the civil power”. You gotta love the self-confidence (if you’re Catholic): The Church had been beaten temporally, but wasn’t conceding an inch morally.