Ok, I asked this on the ask an apologist thing Fr Serpa gave me a great reply, tho I think it’ll go over the head of the traditionalist I’m working on. So how can we as Catholics, explain to traditionalists that Vatican II orders are valid. Not just valid but also licit, as they changed the obvious word “ordain” to “assign” can anyone think of a good reason. BTW just to clarify I do believe Vatican II orders are valid, else I’ve committed idolatry too many times (mass with new priests).
The church is the one who authors the rites under her authority. Therefore if she introduces a rite, or a revision to a rite, and says that the rite is valid, it is valid.
I think the OP’s question has an added dimension in light of Pope Leo XIII’s encyclical declaring Anglican orders to be null and void.
This encyclical is often remembered for condemning a defective Anglican form (for omitting the words “for the office of bishop/priest/deacon”), so some might accuse the Catholic Church of being hypocritical, as we have also deviated from the form that Leo was so insistent upon (and, FWIW, I have recently seen the Ordination of my brother to the Deaconate and then the Priesthood (Diocese of Savannah, GA), and the Bishop does not say ANYTHING (at least not out loud) when laying hands).
But the real heart of the Leo’s declaration focused on lack of proper intent (because the Anglican Church had adopted Calvinist ideas about a non-hierarchical ministry).
As long as the intent and meaning of the form is clear, we can’t get too worked up over which particular words are used. Otherwise, a Sacrament starts to resemble a magical incantation.