Yin and yang, male and female, strong and weak, rigid and tender, heaven and earth, light and darkness, thunder and lightning, cold and warmth, good and evil...the interplay of opposite principles constitutes the universe.
When we see persons of worth, we should think of equaling them; when we see persons of a contrary character, we should turn inwards and examine ourselves.
The man who in view of gain thinks of righteousness; who in the view of danger is prepared to give up his life; and who does not forget an old agreement however far back it extends - such a man may be reckoned a complete man.