Steven Stosny makes an analogy, distinguishing the functions of anger and resentment, as: anger being a fire-extinguisher meant to 'put-out' and prevent immediately harmful situations, from becoming more harmful, while resentment is more like a smoke-alarm: something that is always 'on' (and requires energy and emotions to sustain this alarm-system), and is meant to protect us if, just in case, someone or something harmful from past experience shows up. Resentment and anger differ primarily in the way they are externally expressed. Anger results in aggressive behavior, used to avert or deal with a threat, while resentment occurs once the injury has been dealt and is not expressed as aggressively or as openly.