Before proceeding to a detailed account of the powers of the police and the means to justify their exercise, this chapter describes key political features of the police role. Ultimately, the role is to impartially produce a unique form of practical, substantive justice among citizens, one that they are owed by the state as they encounter physical hazards, interpersonal conflicts, or are subject to behaviors that the law empowers the government to regulate. The role is derived here by a form of bootstrapping, in that it takes a broad survey of what we observe the police do when aspiring to its positivist ideals, distills it into categories, and then describes the political nature of each grouping. In doing so, it concludes policing’s practical, substantive justice consists of protection and rescue from physical harm, the collection of people and evidence for presentation to a magistrate in matters of criminal law, and the brokerage and enforcement of the fair terms of social cooperation in public spaces.