A brief note on my understanding of the relationship between politeness and etiquette.

When I was in school, I often wondered: what are rites? What is politeness? Do rites serve politeness, and does politeness mean observing rites? What are the characteristics of being polite? Must being polite come at the expense of one's own dignity?
I have always had the habit of thinking about things during meals.
At noon today, a word suddenly surfaced in my mind—"politeness"—and I followed that word in my thoughts.
What is the core of what we call being polite?
In the end I reached a conclusion—mutual respect.
Being polite must be premised on mutual respect. Respecting oneself or respecting the other party are merely the yin and yang sides of being polite. As the saying goes, solitary yin does not grow, and lone yang does not thrive.
If one respects only oneself, that can never be called being polite in social interactions. For example, loudly chatting on the phone for hours in a dormitory may seem to be respecting one's basic rights as a resident of the dorm, but in reality, while disrespecting others' rights, one is respecting one's own rights—this is by no means a manifestation of politeness, and I think this should be a social consensus.
Then, can respecting only others—even when such respect comes at the expense of one's own dignity—be counted as a manifestation of being polite? The answer I arrive at is no. This question is highly leading; based on instinctive intuition about language, most people can reach the same result, yet when the question is hidden within real-life examples, the answers become uneven.
The saying "repay resentment with virtue," once revered by people of old and later distorted by scholars of subsequent generations, is a good example. Under this distorted view, it seems that even when others do not respect me or even harm my interests, if I continue to respect them and safeguard their interests, that is a manifestation of maintaining a gentleman's cultivation and of being polite.
In fact, the Analects says:

Repay resentment with virtue—then with what shall virtue be repaid? Repay resentment with uprightness, and repay virtue with virtue.
Confucius believed that one should respond to resentment with uprightness and to kindness with kindness; one should not blur the boundaries of morality, and should follow the feelings in one's heart when responding to resentment.
For example, a colleague gossips about you behind your back, making other colleagues harbor reservations about you. At this point you have two choices.

One, you know you have been wronged, yet you still continue to treat him as a good friend, even though your colleague will continue to gossip behind your back and call you hypocritical.

Two, you feel wronged, gradually distance yourself from that colleague, and draw boundaries to protect yourself.

Three, you feel wronged and want to make the gossiping colleague pay a heavy price.
I believe that from the perspective of one's own interests, no one wants conflict with colleagues, and everyone chooses to take a step back for a brighter future. (Option one)

If one repays resentment with uprightness, then I believe most people would certainly choose to make the gossiping colleague pay a heavy price. (Option three)
Based on this, we can draw a conclusion: being polite must be premised on mutual respect. If the other party has clearly disrespected me, then I need not respect them either.
As for the relationship between rites and politeness, in my view, rites are a tool in social interactions that embodies politeness and a person's cultivation, and are the most direct manifestation of mutual respect. However, rites originally carried class distinctions. When the Duke of Zhou compiled the Book of Etiquette and Ceremonial, the term "rites" became a tool for distinguishing class characteristics. Nobles used whether one understood ritual rules as the core criterion for judging whether one understood politeness. This meant that rustic villagers who did not understand rites were, in the eyes of nobles, crude and impolite.
For example, "no talking while eating, no talking while in bed"—from the perspective of mutual respect, this is to avoid disturbing others' meals and rest. But if it is solidified into a rule, and once someone fails to observe it—even if that person never learned it—they are considered impolite, then in my view, that is putting the cart before the horse.
Another example: if no talking while eating became a mandatory rite, then when my friends and I all enjoy chatting while eating, does that mean we do not respect each other? Does it mean both parties are impolite? I think everyone has the answer in their heart, and that is exactly what I want to say.