To cure the bad, sometimes to treat the bad with the bad, to deal with the big bad with the small bad, and to deal with the real bad with the fake bad, the bad person will also do good things, but as long as good people have done bad things, they will become bad people. From this we can infer:. ['good people cannot rule bad people.', 'there can be no good people in the world.', 'people who have done good things may not be good people.', 'people who have done bad things are not necessarily bad people.']