After broadly defining the basic function of the police as dealing with all those problems which may require the use of coercive force, the author explores several systems of avocational policing and demonstrates why they are not a viable alternative to a professional force. The next chapters trace the evolution of the patrol officer and the detective in British and American police systems. The text emphasizes that democratic societies give the police the right to use morally dangerous, dirty, and illegal means to achieve good ends because in most cases, noble institutions do not contain the means to ensure their survival. The analysis of how police enforce the law considers factors that influence police discretion and proposals to control discretionary enforcement. The final chapter discusses Ken Muir's theories of good police and good policing, using examples from the television program 'Hill Street Blues' to illustrate police organizational styles and four police types -- the professional, the reciprocator, the enforcer, and the avoider. Each chapter includes discussion questions. References and an index are supplied.