Not sure a whole book is needed, it seems fairly straightforward to show that society is based on threats of violence.

If you don't pay someone, that someone can go to a judge. If you indeed did something illegal (e.g. if you did a double spend, money forgery, whatever) you should be declared guilty and ordered to pay the damages plus perhaps a fine. If you don't do that, the amount due will increase and eventually you get ordered to jail. If you don't go voluntarily, they will make you. Of course everything comes down to force and eventually violence in the end. Why else would you comply with things that don't please you? (Because you're an honest party, okay, and the vast majority of people are, but not everyone is in the privileged position where they have what they want without applying dishonesty.)

Even if you think to solve it with technology, preventing a crime is indeed better than detecting and punishing one, but let's say it's impossible to detect the double spend ahead of time and your technological solution only finds out that there was a double spend after the fact. What's it going to do, block your card from now on? In the end, it will still have real world consequences for you. Taking away someone's card, through physical or technological means, it's all more or less the same thing.

One reason I am interested in Bitcoin is that it doesn't rely on violence to enforce it's rules.

It doesn't prevent from physical torturing that can be used to steal your coins. I've already seen a bunch of news about missing or killed people in this field. The creator is also probably dead.

If someone can round up 51% of Bitcoin's miners and hold them at gunpoint, then they have full control over Bitcoin's rules.

Well over 51% of bitcoin mining happens in China, so Xi Jinping can probably change Bitcoin's rules tomorrow if he desires.

> if someone can round up 51% of Bitcoin's miners and hold them at gunpoint, then they have full control over Bitcoin's rules.

This is not true. Most of the rules are maintained using cryptography and game theory.

For someone to break bitcoin, they need to be irrational. i.e spend more than they will benefit from an attack.

And even if such an attack happens, it's very trivial to roll back & undo the damages.

It's not a democracy, it's a game.

It still acts as a token for debt, and the underlying force of that is violent retribution for default

No. contemporary economies have figured out that everyone is better of doing "wealth exchange" instead of coercing people for their wealth.

I think you missed the last paragraph.