Police are often regarded as the thin blue line between anarchy and order - and there is some truth to that notion.

Whenever police services have been removed from a city - as when police strike - crime has risen, although not always by as much as expected. Still, it has risen enough to make most citizens uncomfortable. There is no question that police perform an essential public service. Yet the first formal police department in the Anglo-American countries was not instituted until 1829, in London.

England had sorely needed a major police force for three-quarters of a century. The industrial revolution had encouraged migration to the cities.

Unemployment and economic hardships following the Napoleonic wars led to widespread riots and protests over the climbing price of food. And the rise in urban crime reduced safety in streets and homes. "Society," wrote one historian of the period, "was in violent transition."

Still, most Englishmen - from Tories through Radicals - expressed greater fear of a police force than of crime and riots. Parliamentary commissions considered and rejected the police idea in 1770, 1793, 1812, 1818, 1822, and 1828. At the time, police on the European continent were often oppressive, corrupt, and arbitrary - seemed the relevant model for England.

The problem, was, as it always is for a society that values political freedom, how to reconcile governmental power with individual freedom.

Sir Robert Peel, the home secretary, addressed the dillemma in several ways: First he spent several years reforming the criminal law before introducing his Police Act in 1829. He realized that the new police would not be successful if required to enforce inconsistent, irrational, or exceedingly punitive laws.

Peel and his associates also distinguished the police from the army - feared and mistrusted by the populace - in two respects: Scotland Yard would not accept applications from senior military men for ranking positions in the new police force. Moreover, the Bobbies," as they came to be affectionately known after Sir Robert, were not to carry firearms. Deadly weapons were for the external enemies encountered by the army. The police regulated citizens, and so required guns only for emergencies.

Still, the new police were trained to be and to book authoritive. Unifored police were carefully instructed to be fair and imperturbable. Force, when used, was to be measured, limited, and minimal.

Finally, and most importantly, Peel established the linked ideas of police accountability and public support. Just as police ranks were to be drawn from the class of working people to insure citizen support, police were to be accountable for their actions to Parliament and the courts.

These linked ideas - legal accountability and public support - were the tools to resolve the dilemma between freedom and order.

Although the United States was also a "free society" with laws and institutions modeled on England's, no American police department was so carefully planned and organized as Scotland Yard. The firs full-time United States police force was formed in Boston in 1837, after roving bands of Protestant rioters destroyed nearly every Irish home on Broad Street.

Unlike the English police prior to the 1960s, American police, from the 1830s to the 1970s, have been involved with often tragic ethnic and racial conflict. This has generated special problems for American policing. New York City, for example, experienced a riot in 1900 that grew out of competition between Irish and blacks for jobs and living space. The police did not stop the white rioters who were beating the blacks, they joined them.

In a country with a history of immigration, rapid territorial and economic expansion, and slavery, the quality of law enforcement has often depended upon the question "whose law, whose order?."

Nor has the function of the police ever been clear in the United States, either to the police themselves or to the general public. Most police like to think of themselves as crime fighters.

Studies have shown, however, that about 80 per cent of a police officer's time is spent providing a wide variety of community services and peacekeeping functions such as giving directions, handling traffic accidents, and resolving family disputes. Less than 20 per cent of an average patrolman's time is spent on crime-related activities.

Police enforce the criminal law gyarresting violaters and providing prosecutors with evidence, so as to lead to a conviction - no easy assignment. But police are not usually able to catch criminals in the act. That is why the recent "sting" tactics, where police pretended to "fence" stolen goods but actually photographed the seller and tagged his or her wares, have been so successful. These records show exactly who committed what crime, where, and when.

Ordinarily, police must rely on street informants - themselves involved in crime - for information about crime. In return, police can offer the informant immunity from arrest or some other "break" in the administration of justice.

This practice creates serious problems about the equity and efficiency of police procedures. I once conducted a study of vice detectives and burglary detectives in a respected urban police department. The vice detectives used burglars as informers and did not inquire about their burglaries, while burglary detectives used addicts as informers and ignored their drug offenses.

Because police departments have limited resources, police must employ considerable discretion in carrying out responsibilities. Police chiefs set priorities, employing personal values and departmental standards to govern conduct. Every student of police agrees that this police "culture" heavily influences how police conduct themselves on the job.

Often, police employ discretion sensibly and responsibly. At other times, discretion can deteriorate into police malpractice. Malpractice refers to a broader spectrum of behavior than police corruption. Corruption normally suggests the sale of official authority for personal gain, whereas malpractice includes not only corruption but also mistreatment of prisoners, discrimination, illegal searches, perjury, planting evidence, and other misconduct committed under the authority of law enforcement.

Police culture - especially unwritten codes of conduct and solidarity - is of critical importance here. New York's Knapp Commission found in 1972, that contrary to public thinking, New York police corruption - no worse than in many other city police departments - was not attributable solely to "rotten apples." Where malpractice exists, it usually spans entire police departments.

Policemen everywhere experience feelings of isolation, public rejection, and hostility in a job characterized by danger, authority, and the pressure to produce. Consequently, policemen build up intense feeling of group loyalty, coupled with deep suspicion of outside inteference.

In most American police departments there is a stubborn refusal at all levels to acknowledge that malpractice problems exist, especially corruption.

In the long run, the police themselves, the community, and victims of crime will best be served by police accountability for the quality of their policies and work. Television programs notwithstanding, the U.S. Constitution does not envision police as asphalt cowboys, riding herd on crime and disorder in the central cities.

Police are government officials, armed by law, whose monopoly on force is a public trust in a free and democratic society. They fail when they are transformed into distant and mobile authorities, encased in vehicles, remote from the communities they serve.

Sir Robert Peel understood that when he created the first Western democratic police organization. His ideas about how to reconcile policing and freedom - in periods of rising crime and social turbulence -scarcely seem dated.

The author is professor of law (jusisprudence and social policy) and director of the Center for the Study of Law and Society at the University of California, Berkeley, where he was also a professor of criminology from 1970 to 1977. He previously taught at Yale University, the University of Chicago, and the University of California, San Diego. In 1968-69 he served as director of the Task Force on Violent Aspects of Protest and Confrontation for the National Commission on Causes and Prevention of Violence, and he is author of its report, "This Politics of Protest." His other books include a prize-winning volume on detectives, "Justice Withoug Trail: Law Enforcement in Democratic Society," "Crises in American Institutions," with Elliott Currie, and "Society and the Legal Order," co-edited with Richard Schwartz.

This is the 10th in a series of 15 articles exploring "Crime and Justice in America." This series was written for Courses by Newspaper, a program developed by University Extension, University of California, San Diego, and funded by a grant from the National Endownent for Humanities. Supplemental funding for this course was provided by the Center for Studies of Crime and Delinquency, National Institute of Mental Health.