Olive oil is the proper and ordinary matter, established by apostolic and ecclesiastical authority, but it does not belong to the unchangeable substance instituted by Christ. As +Pius XII teaches, “the Church has no power over the substance of the sacraments… but the Church does have power over those things which it has established” (Sacramentum Ordinis, 42). Thus, in necessity another vegetable oil suffices, since the Church can dispense from her own determinations but never from what Christ Himself instituted.
Both you and Boru are conflating terms. You say olive oil is from Apostolic AND ecclesiastical authority. ?? It cannot be both. Apostolic authority = from Christ, which cannot change. Ecclesiastical authority = Church decision, which can change.
Boru says that Paul6 admitted that olive oil is from Scripture (ie Divine origin) but then says Paul6 is allowed to change it because the Church decided it. ??
Either olive oil is:
1. From Scripture (which it is)
2. From Scripture/Apostles (yes)
or
3) the church decided on Her own.
If you say 1 or 2, then this means it is DIVINELY CREATED, which means it cannot be changed.
If Scripture is involved, it’s unchangeable. If Apostolic authority is involved, this is part of Divine Revelation, and is unchangeable.
The Church can “declare, teach, decide” that something is Scriptural or Apostolic, but that doesn’t mean She can change it. She can only change things which are of human origin (ie canon law, some feast days, etc).