Turning from the Ethics treatises to their sequel, the Politics, the reader is brought down to earth. “Man is a political animal,” Aristotle observes; human beings are creatures of flesh and blood, rubbing shoulders with each other in cities and communities. Like his work in zoology, Aristotle’s political studies combine observation and theory. He and his students documented the constitutions of 158 states—one of which, The Constitution of Athens, has survived on papyrus. The aim of the Politics, Aristotle says, is to investigate, on the basis of the constitutions collected, what makes for good government and what makes for bad government and to identify the factors favourable or unfavourable to the preservation of a constitution.

Aristotle asserts that all communities aim at some good. The state (polis), by which he means a city-state such as Athens, is the highest kind of community, aiming at the highest of goods. The most primitive communities are families of men and women, masters and slaves. Families combine to make a village, and several villages combine to make a state, which is the first self-sufficient community. The state is no less natural than the family; this is proved by the fact that human beings have the power of speech, the purpose of which is “to set forth the expedient and inexpedient, and therefore likewise the just and the unjust.” The foundation of the state was the greatest of benefactions, because only within a state can human beings fulfill their potential.

Government, Aristotle says, must be in the hands of one, of a few, or of the many; and governments may govern for the general good or for the good of the rulers. Government by a single person for the general good is called “monarchy”; for private benefit, “tyranny.” Government by a minority is “aristocracy” if it aims at the state’s best interest and “oligarchy” if it benefits only the ruling minority. Popular government in the common interest Aristotle calls “polity”; he reserves the word “democracy” for anarchic mob rule.

If a community contains an individual or family of outstanding excellence, then, Aristotle says, monarchy is the best constitution. But such a case is very rare, and the risk of miscarriage is great, for monarchy corrupts into tyranny, which is the worst constitution of all. Aristocracy, in theory, is the next-best constitution after monarchy (because the ruling minority will be the best-qualified to rule), but in practice Aristotle preferred a kind of constitutional democracy, for what he called “polity” is a state in which rich and poor respect each other’s rights and the best-qualified citizens rule with the consent of all.

Two elements of Aristotle’s teaching affected European political institutions for many centuries: his justification of slavery and his condemnation of usury. Some people, Aristotle says, think that the rule of master over slave is contrary to nature and therefore unjust. But they are quite wrong: a slave is someone who is by nature not his own property but someone else’s. Aristotle agrees, however, that in practice much slavery is unjust, and he speculates that, if nonliving machines could be made to carry out menial tasks, there would be no need for slaves as living tools. Nevertheless, some people are so inferior and brutish that it is better for them to be controlled by a master than to be left to their own devices.

Although not himself an aristocrat, Aristotle had an aristocratic disdain for commerce. Our possessions, he says, have two uses, proper and improper. Money too has a proper and an improper use; its proper use is to be exchanged for goods and services, not to be lent out at interest. Of all the methods of making money, “taking a breed from barren metal” is the most unnatural.

Rhetoric and poetics

Rhetoric, for Aristotle, is a topic-neutral discipline that studies the possible means of persuasion. In advising orators on how to exploit the moods of their audience, Aristotle undertakes a systematic and often insightful treatment of human emotion, dealing in turn with anger, hatred, fear, shame, pity, indignation, envy, and jealousy—in each case offering a definition of the emotion and a list of its objects and causes.

The Poetics is much better known than the Rhetoric, though only the first book of the former, a treatment of epic and tragic poetry, survives. The book aims, among other things, to answer Plato’s criticisms of representative art. According to the theory of Forms, material objects are imperfect copies of original, real, Forms; artistic representations of material objects are therefore only copies of copies, at two removes from reality. Moreover, drama has a specially corrupting effect, because it stimulates unworthy emotions in its audience. In response, Aristotle insists that imitation, so far from being the degrading activity that Plato describes, is something natural to humans from childhood and is one of the characteristics that makes humans superior to animals, since it vastly increases the scope of what they may learn.

In order to answer Plato’s complaint that playwrights are only imitators of everyday life, which is itself only an imitation of the real world of Forms, Aristotle draws a contrast between poetry and history. The poet’s job is to describe not something that has actually happened but something that might well happen—that is to say, something that is possible because it is necessary or likely. For this reason, poetry is more philosophical and more important than history, for poetry speaks of the universal, history of only the particular. Much of what happens to people in everyday life is a matter of sheer accident; only in fiction can one witness character and action work themselves out to their natural consequences.

Far from debasing the emotions, as Plato thought, drama has a beneficial effect on them. Tragedy, Aristotle says, must contain episodes arousing pity and fear so as to achieve a “purification” of these emotions. No one is quite sure exactly what Aristotle meant by katharsis, or purification. But perhaps what he meant was that watching tragedy helps people to put their own sorrows and worries in perspective, because in it they observe how catastrophe can overtake even people who are vastly their superiors.