刚柔相济[ gāng róu xiāng jì ]

⒈ 刚烈与柔顺相互弥补，柔硬兼施，恩威并用。例凡为将者，当以刚柔相济，不可徒恃其勇。——罗贯中《三国演义》英temper force with grace; the strong and weak mutually assist each other;