Breaking the Rules When Others Do

People often speak as if the behaviour of others is relevant to the question of whether they are justified in violating a rule. This paper explores three lines of argument which might be used to justify rule violation on grounds appealing to what others do. The appeal to self-defence as a justification does not succeed, since it must expand the concept to involve a cumbersome weighing of harms. The argument that complying with a rule may involve too great a sacrifice in some cases needs to be developed by an account of when a sacrifice is morally significant. It is tempting, but problematic, to do this by weighing consequences of individual acts. An alternative approach is to argue that the behaviour of others is sometimes relevant to determining what rule is actually functioning in some context as a part of a particular moral system.