What exactly is stopping Erik from strangling himself on his chains, especially when Alexi is asleep and Joseph is out of the room?

Also, I might want to work with you on some of the history of this alternate world we've made up. I kind of already decided that technological advancement happened the same way. But what about the various wars? Most notably, what about human on human slavery? Was there a need to enslave other humans in the last 500 years after magicals were available as free labor?

I'm asking because I want to use a Frederick Douglas quote, but I need to know how it would have originated in this world.