Numerous books describe the rules of etiquette.
Conclusion (so)
It is absurd to label any one set of behaviors as correct and others as incorrect.
Evidence
Some books describing the rules of etiquette codify some behaviors as polite (correct) and other behaviors as rude (correct).
This suggests that there is one single, objective standard of politeness, but standards of politeness vary from culture to culture.
Evaluate
We might actually consider this argument having three conclusions, "this suggests / clearly / so". When arguments have multiple conclusions, we want to think about objections we could make at each level of the argument.
The final move to the conclusion is saying, .
That seems flawed. We can't say, After all, maybe one of them was obviously way better than all the others.
Similarly, we need to allow for the possibility that even though different cultures have different standards, one set of standards just happens to be better than all the others.
The author made a move from saying, .
Do they suggest that? We could push back here and say,
Goal
Look for an answer defending the idea that you can codify a set of behaviors without it suggesting that the set you're describing is the one, correct set.
Or look for an answer saying that,
We might also see an answer pointing out the language drift from "polite" to "correct" and from "rude" to "incorrect".