A retributive theory of punishment must at least say that it is a necessary condition for the justification of a punishment that the person punished should be guilty. But “guilty” here may be taken in two different senses, giving two very different kinds of justification. In the first sense, to be guilty is to have wilfully disobeyed a law or order of some authority, and it is the defiance of this authority which justifies punishment. Mr. Mabbott has put up a good case for a view of this kind. It is clear that we regularly do justify the punishment of offenders on the ground that they have broken rules, and therefore deserve to be punished. And there are some moral situations (those of officials charged with the administration of regulations) in which this is the only fact to be considered in deciding whether or not to punish. As to the view that this constitutes the only valid justification of punishment, I wish to make two comments.