Book 8 opens Aristotle's long treatment of friendship by insisting that no one would choose to live without friends, even with every other good. Wealth, office, and power still leave a person exposed without trusted allies to help, guard prosperity, and give beneficence its natural field. Friends guide the young away from error, support the old when strength fails, and help adults in their prime think and act more nobly together. Aristotle also notes how friendship appears in nature, among parents and offspring, fellow citizens, and even travelers who discover how near every human being is to every other. Lawgivers care intensely about friendship because it produces something like civic unanimity; where friends are just, they still need friendship, and the truest justice has a friendly quality. His method is to preserve common opinions while sorting which claims about likeness, opposition, and degrees of affection actually hold up.
The analysis begins with what people love. We love the lovable, and what seems good, pleasant, or useful counts as lovable to the one who loves it. Mere goodwill is not yet friendship; friends must wish one another well for the other's sake and recognize that wish reciprocally. Aristotle then distinguishes three kinds of friendship according to what is loved in the friend: utility, pleasure, and the good. Friendships of utility are common among the commercially minded; friendships of pleasure are common among the young, who delight in each other's company. Both are real friendships in a qualified sense, but they are less complete and less stable because they depend on incidental benefits that can vanish when circumstances change. Perfect friendship exists between good people who are alike in virtue and wish good to one another for the other's sake. Such friends live together in the practical sense, sharing discussion and thought, and their bond endures because character is comparatively stable.
Aristotle stresses that friendship depends more on loving than on being loved. We praise those who love their friends reliably, and only friendships rooted in due measure of love endure. Complete friendship is rare because one cannot maintain many perfect friendships at once, any more than one can be passionately in love with many people simultaneously. Virtue friendship requires time, familiarity, and mutual recognition of goodness. Lesser friendships can be more numerous because utility and pleasure are easier to supply in small doses. Sour and elderly people make friends slowly because they enjoy companionship less, though they may still bear goodwill and help in need. Wicked people may enjoy each other's vice briefly, but they have no steadfastness. Even happy people need pleasant companions, though ideally those companions should also be good. People in authority often split their circle between useful allies and amusing companions, rarely finding both virtues in one person unless the subordinate also excels in character.
Friendship and justice run on parallel tracks. Every community has its form of justice and its form of friendship, from fellow voyagers to fellow citizens, and the extent of shared life determines the depth of both. Brothers and comrades hold more in common than casual associates, and injustice toward a closer friend is more terrible than injustice toward a stranger. Aristotle maps political constitutions onto friendship types: kingship and paternal rule involve superior benefit, aristocratic marriage resembles virtue friendship among unequals, and timocracy resembles brotherly equality. In corrupt regimes, especially tyranny, friendship barely exists because ruler and subject share no common good. Even a slave can be a friend qua human being, though not qua slave, because some justice remains between persons capable of law and agreement. Kinship friendship grows from parental love, shared upbringing, and the sense that children are another self; man and wife form a household bond that is more necessary than the city itself because human life requires divided labor and common purposes beyond reproduction.
The chapter closes on inequality and complaint. In equal friendships, partners should wish the same good for one another; in unequal friendships, each must render what is proportionate to merit, as between parent and child, ruler and subject, husband and wife. Utility friendships generate the most reproaches because each side tries to get the better bargain and feels shortchanged. Legal utility friendships operate on fixed terms; moral utility friendships give as to a friend but still expect return, which breeds resentment when the relation dissolves badly. In superior friendships, the better or more useful party wants more honor, while the inferior party wants more material benefit; friendship survives when honor goes up and gain goes down in due proportion, as in civic life where public honor substitutes for private wealth. Parents confer benefits no son can fully repay, yet a good son serves to the limit of his power. Aristotle leaves Book 9 to press harder cases: proportional return among unequals, broken friendships, and whether noble self love can ground loyalty rather than undermine it.
