Transferred the oath from a written Constitution to a mental idea ideas change yes Constitution doesn't change gears change they change over time that you change based on the cultural norms of the society so what he is telling those young officers is that you took an oath to defend and fight for the ideas that we today say are in effect yet so if they declare a socialist and communist take atheistic value system to be the ruling mindset of the country that you have taken an oath to those ideas, United States against all enemies foreign and domestic but I will bear true faith and allegiance to the same day I take this obligation freely without any mental reservation or purpose of evasion and that I will well and Faithfully discharge the duties of the office on which I'm about to enter so GOD!