Try not to do anything against etiquette

Etiquette to society is what apparel is to the individual. Without apparel men would go in shameful nudity which would surely lead to the corruption of morals; and without etiquette society would be in a pitiable state and the necessary intercourse between its members would be interfered with by needless offences and troubles. If society were a train, the etiquette would be the rails along which only the train could rumble forth; if society were a state coach, the etiquette would be the wheels and axis, on which only the coach could roll forward. The lack of proprieties would make the most intimate friends turn to be the most decided enemies and the friendly or allied countries declare war against each other. We can find many examples in the history of mankind. Therefore I advise you to stand on ceremony before anyone else and to take pains not to do anything against etiquette lest you give offences or make enemies. 
禮儀之于社會猶如衣著之于個人。人若不穿衣服，就會一絲不掛，令人恥笑，必然導致道德敗壞，社會要是沒有禮儀，就會陷入可悲的境地，而社會成員之間所必需 的交往就會被無謂的沖突和糾紛所干擾。假定社會是一列火車，禮儀就好比軌道，火車只能沿著它隆隆前進。假定社會是一輛貴賓車，禮儀就好比輪子與軸，馬車只有靠它們才能滾滾前進。缺了禮節，最親密的朋友會變成死敵，友好或結盟的國家會兵戎相見。我們可以從人類歷史上找到許多這種例子。因此我勸你對于任何人都要講究禮儀，并且盡力不做違背禮儀的事，以免冒犯他人或者樹敵。