The word
君子, jūnzǐ, literally means "a lord's son": at first, an aristocrat, someone of rank. Confucius and his school changed the meaning: the nobility that counts is nobility of conduct. In Cambios we say "the noble person," without gender, because the ideal speaks to anyone. Older translations often say "the superior man" or "the gentleman."
Where it appears
It runs through the whole book, and above all through the image of each hexagram, which almost always ends the same way: "So the noble person…" In Activity: "Heaven moves with strength. So the noble person grows strong and does not rest." The image shows nature; the noble person learns from it how to act.
In the judgments and lines it often appears beside its opposite, the petty person. In Leaving Behind, a timely retreat brings good fortune to the noble person, but not to the petty one. The same situation turns out differently depending on who's living it.
What it isn't
It isn't a saint or a hero. It's someone who reads the moment, corrects course and isn't swayed by quick gain. Above it, in rank and reach, stands the great person.
In a reading
When a text mentions the noble person, it's offering you a model: how someone with integrity would act in your place. It's not a verdict on you but an invitation.