Origin of the Enchiridion?

[Berethos]

The bare facts would certainly be sufficient for the short term, and might have even been sufficient in the long run...

But why deal with a might when some propaganda can further cloud the truth, extending the length of the ruse?

Also, changing how the government worked - from King to Church guiding four houses - would be a transition made easier by such propaganda.

So it wasn't a necessary act, but creating that compelling narrative made their long term goals easier to achieve.

Even with the ruse of a "just cause" fueling their society the people grew weary of the long years of war and needed a strict system of punishments to keep the populace toeing the line. A thousand years of just fighting a mad dragon for no other reason than they keep attacking could have led to questions long ago...questions that may have never stopped the war but possibly destabilized the government and weakened its power...

And this was a system put in place by those who broke a two century peace for power. That they'd do whatever they could to keep themselves in power makes sense.

On a different note specific to the Enchiridon - the Scholisticate quest line does seem to imply that the text is not at all immutable, and some parts of it are clearly treated as secondary to other parts even in present day Ishgard. While it may have changed little in a thousand years, that parts of it are held in lower regard and the duplicity of the founders of the system of government they used strongly suggests to me a clear timeframe for it to have been altered, possibly significantly.