As society, we csay that although the act is bad, because you do it in self-defense it is justified. You are doing it in response to something else. Excuse: has less to do with the act. We are not saying the act is okay. With excuse, we are saying that there is no justification for the act, but we are going to excuse the actor because he doesn"t have the moral blameworthiness required to hold him criminally liable. There is a focus on me in mpc, as opposed to what the bad guy is doing in common law. With mpc, the language is that the actors believes that he must respond. There is more of a focus on the person who feels he is being attacked. Mpc also does not include the word reasonable. United states v. peterson: facts: the victim drove to an alley behind the defendant"s house to obtain windshield wipers off of the defendant"s junked car.