Note: This is the seventh in a second series of essays and reflections about politics and the moral life. The themes of the essays are drawn from Plato’s “Laws,” his last and longest philosophical dialogue written shortly before his death in 347 BCE. “Laws” is a fictional account of a conversation about government involving three old men with long experience in politics: Cleinias, from the Cretan city of Cnossos, Megillus, from Sparta, and an Athenian stranger who is not named, but who may be Plato himself.
The constitution of Magnesia, which the three companions devise is mixed, combines elements of monarchy, democracy and aristocracy. It grants power to individuals and selects groups to govern and fixes their duties. These public officials are chosen by the people or by some significant subset of them. All public offices are dedicated to establishing and maintaining peace, security, public welfare and justice.
Achieving these ends requires a complex system of governmental institutions and offices that divides up power and distributes it so that no one has too much of it or any unregulated use of it. It is a system designed to bring everyone under the dominion of civil power, which, in turn, is under the constraint of law.
Public officials are elected either by preferential vote, or by lot, or by a combination of both. As a rule they are elected at large, but there are notable exceptions; just as bearing arms, voting and holding public office are duties. They are complementary.
The Citizens
Citizens have as great a duty to preserve their city from internal disorder and corruption, for which they must be prudent, temperate and well informed—as they have to protect it from outside aggression, and so they must be brave, disciplined and suitably armed. By these means, a city is defended and preserved in all respects.
Because voting is a civic duty, voters may be held accountable in their performance of it, for they are obliged to choose the best. In some instances they may be required to submit signed ballots and defend their choices. It is assumed that voting is a deliberative act. Failure to vote is a misdemeanor for which there may be a fine.
The assembly or legislature
The assembly is the gathering of all the people from the 12 demes or tribes. They choose the most important magistrates of the city. These are the Guardians of the Law, the Examiners, and the Generals. The constitution prescribes that there be 37 Law Guardians selected at large beginning with a nominating ballot and continuing until the requisite number is selected. Guardians must be at least 50 years old and may serve until they are 70. The Guardians have a variety of duties: legislative, executive, judicial and deliberative. They have access to all other institutions of government, for as their title implies, they are empowered to protect and preserve the rule of law.    
The Examiners or judges
The Body of Examiners has a similar function. It also is selected at large from all who are over 50. Every voter is obliged to nominate three individuals who he or she believes to be of the highest moral integrity, and the balloting proceeds until three are chosen. This is done annually. Examiners serve until they are 75. They are the rulers or superintendents of all other rulers. They are on the lookout for dishonesty and corruption in government, and have power to prosecute perpetrators of it.
The Militia
The constitution prescribes that there be three generals or military commanders. Nominations are made by the Law Guardians to the assembly from the highest property class. Recall that voters are also members of the militia, and it is in this capacity that they gather to elect their generals. Nominations may be added from the assembly, and the vote proceeds, by a show of hands, until three are elected. No mention is made of the length of terms. As militia, the assembly is divided into three groups: cavalry, heavily armed troops, and light armed militia, which given the cost involved in outfitting is another division into property classes. Each group chooses its leader, and so on down the line in the case of subdivisions in each group. The generals maintain the defenses of the city against foreign aggression and oversee the training and discipline of the militia.   
The City Council
The routine business of governing is the responsibility of another corporate institution: the City Council. It consists of 360 members chosen annually by the people. Membership in the Council is apportioned among the property classes. Plato seems to presuppose that the largest property class will be the poorest, that the size of each decreases as we ascend the ladder of wealth. He also supposes that moderate wealth provides more leisure for self-education, and that the wealthier classes will therefore be better fit to govern. The Athenian Stranger justifies this as an example of mixed government, privileging the few while enfranchising all.
Once elected, the Council is divided into 12 groups, one for each month of the year, so that its actual working size is 30. The Council’s main task is to see that the city runs on an even keel. It makes treaties with other cities, enacts emergency measures to meet domestic crises, and enacts laws that are more rules of convenience that expressions of principle.
The city’s routine business involves two kinds executive position: city managers and market regulators. City managers are nominated by the assembly: citizens may nominate from among the wealthiest propertied class individuals whom they believe are of the highest competence and integrity. A series of runoffs follows until there remain only six candidates, from whom three are selected by lot—for Plato, the randomness of a lottery is symbolic of the popular will.
The city is divided into three districts, each manager is assigned a district and oversees its roads, public buildings, and the water supply. City managers are also responsible for public safety. A similar procedure is used to select five market regulators. These officials oversee the city markets. They attend to such matters as weights and measures, coinage, product reliability and fair trade practices. City managers and market regulators have judicial and executive power over their domains.
The Nocturnal Council?
Finally, among bodies of government, there is one curiously named the Nocturnal Council. The name signifies its time of meeting: at the end of night, at the first light of dawn; it sessions last until sunrise. Its membership is not fixed. It includes the twenty most senior Law Guardians. Other individuals are added: priests and magistrates, who have distinguished themselves, and young men of promise. Its function within the government is mainly deliberative; it is an institution of advanced study whose main subject is civil law and policy. It includes among its membership world travelers, who bring them knowledge of the constitutions and laws of other states to which they can compare their own. Their function is not to make policy, but to consider ways of making policy more perfect.
This is only a bare bones account of the government of Magnesia. Note how power is distributed among officials and groups, and also that no provision is made for a chief executive. Note also how deeply embedded in the whole system of government is the deliberative role. And while there is much supervision: especially by the Law Guardians and Examiners, they are supposed to exercise this power not by threats or harsh repressive measures but by persuasion.
Politics for Plato is not supposed to be a vocation driven by ambition, but a set of functions and duties pragmatically conceived. It is similar, in this respect, to our town government.