The Mysterious Manuscripts

[Darkness Ascendant he/him]

Hello everyone, I literally just finished the first Rithmatist book and I have a few questions.....

During the read, at the end of every Chapter(or start) there is a page explaining an aspect in Rithmatism like say a type of Defence or how you duel.

Who wrote them?

At first I thought it was Joel's father considering the scene where Joel enters his father's workshop after all this time to discover the new line. Surrounding the piece of paper with the new line there were sheets explaining defences and techniques used by Rithmatists around the world. 

 

But  then in the battle between Fitch and the Forgotten there was a page that was titled "Joel's sketch of the Rithmatic Dorms Second Floor that night"

 

So was it Joel who wrote the manuscripts or his father?

[king of nowhere]

I don't think it matters. Rithmatist is not cosmere, so there isn't some worldhopper going around collecting data. I always assumed those sketches of rithmatic defences came out of textbooks or something.

[Modal Seoul he/him]

Brandon Sanderson wrote those of course. Only a genius like him could.