The basic meaning of “rectitude” is uprightness. More specifically, there are two interpretations of “rectitude.” The first interpretation refers to words and deeds that meet the moral standards or the rules of propriety. To be “upright” is to refrain from doing anything immoral or illegal for the sake of personal gain. However, because there are different understandings of morality and propriety, there are also different views, even conflicting ones, of how “rectitude” is manifested. The second interpretation of being “upright” is acting in accordance with facts and not concealing the truth in order to meet the expectations or needs of others.
Treat a person you hold a grudge against with upright behavior. “Repaying a grudge with rectitude” was a principle proposed by Confucius(551-479 BC) for dealing with grudges. He felt that both “repaying a grudge with a grudge” and “repaying a grudge with kindness” were incorrect. Confucius argued that one should not deliberately seek vengeance out of momentary anger, nor should one conceal resentment over a grudge and repay it with kindness. Rather, one should analyze the rights and wrongs of the episode which created the grudge, and respond according to the principles of rectitude.
This term suggests that when there is a good cause to use military force, the troops will be high in morale and valiant in fighting. The word shi (师) here is a general term for all military forces and operations. The word zhi (直) means a just cause. The word zhuang (壮) means powerful troops. The Chinese nation has always been wary of waging wars, believing that a war should be fought only for a just cause and that an army fighting for such a cause will have high morale and win the war.