Every person is responsible for themselves and their actions or their failure to act. However, in a society, every person also has a duty, an obligation, to act (or not act) in a way which is responsible for others. This is why we as a society have laws. The Laws are the Rules to live by; if you break or disobey those rules, you can hurt yourself and others around you. For example, we stop at red lights. We punish those who do not. If a red light "runner" causes a crash or hits a pedestrian, we can hold that "runner" responsible for the harm that results from his lack of responsibility - his carelessness and negligence - in a courtroom.