All societies recognize certain rules to be so crucial that they define those rules as duties, such as rules restricting violence and those requiring the keeping of agreements.
Background
All societies have certain rules that are so crucial they're called "duties".
The idea of "duty" is that it's so important that you have to do it even if doing it would be harmful to your self-interest.
Evaluate
The phrase "this shows that" tells us that we're trying to draw a conclusion. This is typically what we're doing on Logical Completion, and we want to use our Inference brain to think about what a safely worded conclusion would sound like.
We also want to use our Inference brain in the sense that the correct answer will feel like it's synthesizing two or more claims. This argument only has two claims. Is there any overlapping information?
Yes, "duty" is talked about in each claim.
All societies have duties. Duties are so important to a properly functioning society that you have to do them even if they're harmful to your self interest.
So we could fuse those together and say something like, .
Goal
It's hard to get a great feel for where this would be headed, but we want to think like we do on Most Supported questions: pick whichever answer feels most provable based on what we read. Beware strong language or out of scope ideas.