Malignant narcissists and psychopaths are dangerous. They are predators. They are deceitful. It is to our advantage to know that they exist among us. We need to learn more about narcissists and psychopaths, so that we stop suffering at their hands. We need to be able to identify these individuals so that our workplaces can be happy fulfilling places and vulnerable populations such as those with special needs do not suffer at their hands.
Sometimes a person without empathy is called a psychopath, sociopath, or narcissist. A psychopath and a sociopath are basically the same thing. All psychopaths are narcissists, but not all narcissists are psychopaths.