When we as the laity decide how to interpret various Church documents, it is helpful to maintain a sense of humility, allowing for the possibility that we do not have it quite right. In such cases common sense would ask for what position is most consistent with the totality of what we are told by our Church.
It’s not clear what you’re objecting to here: my claim as to what the church taught for 2000 years, what she taught from 1997 until 2018, or what she teaches now. What totality do you refer to?
… it makes sense to ask if a supposed position we have deduced from an older, more obscure source is consistent with the Catechism.
Do you dismiss Augustine, Aquinas, all the Doctors and Fathers, and all the previous councils, catechisms, and popes as “obscure”? Besides, a teaching does not gain authority from being included in the catechism; its authority derives from its original source, regarding which the 2018 change seems to be a bit light in substance.
But again, just as with (name removed by moderator), you assume that your interpretation of the catechism is correct when this is the very point being debated.
Looking through the Catechism for every possible reference to capital punishment, one does not see support for exactly the position you stated, which was: “ It is justice that obliges capital punishment, not protection. ”
Why should we be limited to the catechism? Protection is clearly not the primary objective of punishment so it didn’t seem necessary to enlarge on that point. Here is the USCCB from 1980:
We grant that the need for retribution does indeed justify punishment
Sin deserves punishment; it is in fact the only thing that does.
God does not delight in punishments for their own sake; but He does delight in the order of His justice, which requires them. (Yeah, that’s Aquinas. Sorry for the old reference, but he just clarifies things so well.)
Justice demands punishment, and the degree of punishment must be commensurate with the severity of the crime (CCC 2266). If, therefore, anything at all can justify capital punishment, it can only be a crime that deserves such a severe penalty. Nothing else would permit its use, and certainly not protection. We don’t get to execute someone who doesn’t deserve to die simply because it makes us safer.
So preferring one Catechism over another, or one Encyclical over today’s Catechism does become a matter of cherry-picking
I don’t have to choose between catechisms; they can all co-exist under my position. It is only your position that requires one to choose between them, that has them saying different things.