couple hardness with softness; temper force with mercy (/toughness with gentleness) ❍ 凡为将者，当以～，不可徒恃其勇。(《三国演义》615) Every leader must exercise a combination of inflexibility and yeilding. Boldness is not the only thing that counts.
刚柔相济gang rou xiang ji
combine firmness and flexibility
刚柔相济
combine firmness and flexibility;temper toughness with gentleness
刚柔相济ɡānɡ róu xiānɡ jì
刚强的与柔和的二者互相制约、补充。temper force with mercy, temper toughness with gentleness, temper severity with mercy