 Fourth, the act or omission ought to be wrongful. One can make sense of punishing another for an act that is not wrong (see Tadros 2016: ch. 17; Cornford 2017). But as a normative matter, if not a conceptual matter, such punishment is to be avoided if possible. (For arguments that it is possible for a well-developed legal system to generally or always avoid knowingly punishing acts that are not wrongful, see Duff 2018: chs. 2 and 7; Walen forthcoming).