Regulator: It is important to keep in mind, in case you didn’t know, that whenever the Church “defines” a teaching it doesn’t mean that it wasn’t always held or taught. The “new” definition is to bring about clarity and oftentimes it happens because others have challenged the teaching. It does not mean that it suddenly became teaching. I think this is something that non-Catholics misunderstand.
“whenever the Church “defines” a teaching it doesn’t mean that it wasn’t always held or taught.
Historically, it is because there are competing views. Often considered a threat to the Papacy.