Many philosophers think that if you're morally responsible for a state of affairs, you must be a cause of it. Ingmar Persson argues that this strand of common sense morality is asymmetrical, in that it features the act-omission doctrine, according to which there are stronger reasons against performing some harmful actions than in favour of performing any beneficial actions. He analyses the act-omission doctrine as consisting in a theory of negative rights, according to which there are rights not to have one's life, body, and property interfered with, and a conception of responsibility as being based on causality.