Governing a nation, state, or other political unit requires the establishment of rules to control the behavior of its citizens. Governments create and enforce these rules, protect its citizens against internal and external threats, provide public services, and raise revenue. Different types of governments differ in their methods of rule, but all have the same basic responsibilities.
Among the most important functions of government are maintaining military and local police forces to preserve life, property, and liberty against attacks by foreign despots and domestic criminals. To do this, they must also conduct intelligence activities, limit the entry of aliens who may be spies or terrorists, imprison or expel the agents of foreign powers, and embargo the exportation of materials that might aid potential enemies.
Most governments have an additional function of preserving their people against the effects of economic depressions. To do this, they must conduct economic planning, regulate business, and promote social welfare programs. Some nations maintain universal medical insurance, provide food stamps, and operate educational systems. Others, like the United States, have unemployment compensation and welfare payments to help citizens get back on their feet after losing a job.
To do this, they must collect taxes, control prices, and distribute the fruits of its industrial and agricultural labors to all citizens. This is one of the most difficult jobs that a government has to do. It is not easy to maintain a balance between these competing interests and make sure that a sufficient level of freedom insures the integrity of a free economy.
Many different ideas have been proposed about the purpose of government. David Hume, a British philosopher of the 1700s, suggested that the primary reason for any government is to provide its citizens with “public goods.” He defined a public good as something that possesses two particular characteristics. First, a public good is a non-rivalrous commodity, meaning that it cannot be consumed without diminishing its supply.
While the definition of a public good is debatable, most would agree that governments need to set some sort of standards for behavior, to collect taxes to pay for their systems and programs, and to provide protection against internal and external threats. Whether or not a particular form of government accomplishes these goals effectively is another matter altogether.
Modern classifications of government usually include the three major categories of democracies, totalitarian regimes, and authoritarian regimes with a wide range of hybrid forms. They usually depend upon who is in control: a single person (an autocracy), a small group of people, such as military officers, landowners, or wealthy families (an oligarchy) or the people at large (a democracy). The most popular modern forms of government are a republic, a democracy, and a monarchy. In general, the more a nation or society follows democratic principles, the closer it is to a pure democracy. A republic has a parliamentary system with elected officials and checks and balances on power, and the constitution is written to keep the federal government limited in scope. A monarchy is ruled by a hereditary monarch.