The Wrecking Of Names

If he ever got power (which he never did) Confucius said his first priority would be the ‘rectification of names’. Like a boor, I never quite understood this. As The Analects said:
13.3 Zilu asked, “If the Duke of Wei were to employ you to serve in the government of his state, what would be your first priority?” The Master answered, “It would, of course, be the rectification of names (zhengming ).” Zilu said, “Could you, Master, really be so far off the mark? Why worry about rectifying names?” The Master replied, “How boorish you are, Zilu! When it comes to matters that he does not understand, the gentleman should remain silent.
I felt like Zilu (Master Kong’s usual rhetorical punching bag) because I simply didn’t understand the point. Even when the master explained: