To administer reproof to anyone in the presence of others is very impolite. To scold at any time is unwise.
Never undertake a commission for a friend and neglect to perform it.
Never play a practical joke upon anyone, or answer a serious remark by a flippant one.
Never lend a borrowed book, and never keep such a book a single day after you are done with it.
Never pass between two persons who are talking together; and never pass before persons when it is possible to pass behind them. When such an act is absolutely necessary, always apologize for so doing.
"Never speak of a man's virtues before his face, or his faults behind his back," is a maxim to be remembered.
Another maxim is, "In private watch your thoughts; in your family watch your temper; in society watch your tongue."
Never address a mere acquaintance by his or her Christian name. It is a presumption at which the acquaintance may take offense.
Haughtiness and contempt are among the habits to be avoided. The best way is to deal courteously with the rude as well as with the courteous.
In the presence of others, talk as little of yourself as possible, or of the business or profession in which you are engaged.