A current question is whether the criminal sanctions system can and must (and if so, how) contribute to protecting society against individuals deemed dangerous. The debate about this in the Netherlands is fairly theoretical. The discussion has become strongly intertwined with the dogmatic distinction between punishment and measure. We tend to assess the nature of sanctions according to where they are housed within the sanctions system (on the punishment or the measure track); that assessment then often determines our judgement of which guarantees we consider necessary. This gives rise to two related questions. The first is whether our view has in this way become too narrow; within the choice for a particular theoretical model lurks a certain preselection of arguments and solutions. The second question is whether the discussion about the sanctions system is a purely theoretical affair. Many of the choices made are based, after all, on very practical considerations, such as an acute shortage of cells, lack of resources, political ambitions or a need to react to issues of the day. The question is then whether or not this non-theoretical reality (that I call ‘pragmatic’) deserves more recognition in the discussion. The aim of this book is to contribute to the deliberations about our sanctions system. The question to be addressed is not about what the most appropriate system is and how it should ideally be organised, but rather how the debate about the organisation of the sanctions system should be conducted. Based on this question, a reconnaissance of the law is carried out with regard to the sanctions system in England and Wales, and the significant developments that the system has undergone during the second half of the twentieth century.