Let Man use this cosmic order as a model for the structure of human society and let him make it the principle of his each and every action. This is what is called reigi-zaho. By abiding by this rule, Man can rise. Pope, patriarch, cardinal, bishop. All of those relations apply concurrently.
Proper etiquette means to find a proper balance, case by case.
To preserve order, one must observe politeness towards the master, correct attitude towards the sempais, proper etiquette towards kohais and dohais. The observance of those rules is, I believe, the equilibrium and survival condition of the societies we just talked about. However if those instincts escape proper control, every act becomes violent and we thus start picking on the weak or despising them. Or, conversely, we crawl in front of the strongest while hating them at the same time. When actions are directed by etiquette, a space is created which allows one to easily control emotions.