Friendship, as understood here, is a distinctively personal relationship that is grounded in a concern on the part of each friend for the welfare of the other, for the other’s sake, and that involves some degree of intimacy. As such, friendship is undoubtedly central to our lives, in part because the special concern we have for our friends must have a place within a broader set of concerns, including moral concerns, and in part because our friends can help shape who we are as persons. Given this centrality, important questions arise concerning the justification of friendship and, in this context, whether it is permissible to “trade up” when someone new comes along, as well as concerning the possibility of reconciling the demands of friendship with the demands of morality in cases in which the two seem to conflict.
Friendship essentially involves a distinctive kind of concern for your friend, a concern which might reasonably be understood as a kind of love. Philosophers from the ancient Greeks on have traditionally distinguished three notions that can properly be called love: agape, eros, and philia. Agape is a kind of love that does not respond to the antecedent value of its object but instead is thought to create value in the beloved; it has come through the Christian tradition to mean the sort of love God has for us persons as well as, by extension, our love for God and our love for humankind in general. By contrast, eros and philia are generally understood to be responsive to the merits of their objects—to the beloved’s properties, especially his goodness or beauty. The difference is that eros is a kind of passionate desire for an object, typically sexual in nature, whereas ‘philia’ originally meant a kind of affectionate regard or friendly feeling towards not just one’s friends but also possibly towards family members, business partners, and one’s country at large (Liddell et al., 1940; Cooper, 1977a). Given this classification of kinds of love, philia seems to be that which is most clearly relevant to friendship (though just what philia amounts to needs to be clarified in more detail).
For this reason, love and friendship often get lumped together as a single topic; nonetheless, there are significant differences between them. As understood here, love is an evaluative attitude directed at particular persons as such, an attitude which we might take towards someone whether or not that love is reciprocated and whether or not we have an established relationship with her. Friendship, by contrast, is essentially a kind of relationship grounded in a particular kind of special concern each has for the other as the person she is; and whereas we must make conceptual room for the idea of unrequited love, unrequited friendship is senseless. Consequently, accounts of friendship tend to understand it not merely as a case of reciprocal love of some form (together with mutual acknowledgment of this love), but as essentially involving significant interactions between the friends—as being in this sense a certain kind of relationship.
Nonetheless, questions can be raised about precisely how to distinguish romantic relationships, grounded in eros, from relationships of friendship, grounded in philia, insofar as each involves significant interactions between the involved parties that stem from a kind of reciprocal love that is responsive to merit. Clearly the two differ insofar as romantic love normally has a kind of sexual involvement that friendship lacks; yet, as Thomas (1989) asks, is that enough to explain the real differences between them? Badhwar (2003, 65–66) seems to think so, claiming that the sexual involvement enters into romantic love in part through a passion and yearning for physical union, whereas friendship involves instead a desire for a more psychological identification. Yet it is not clear exactly how to understand this: precisely what kind of “psychological identification” or intimacy is characteristic of friendship? (For further discussion, see Section 1.2.)
In philosophical discussions of friendship, it is common to follow Aristotle (Nicomachean Ethics, Book VIII) in distinguishing three kinds of friendship: friendships of pleasure, of utility, and of virtue. Although it is a bit unclear how to understand these distinctions, the basic idea seems to be that pleasure, utility, and virtue are the reasons we have in these various kinds of relationships for loving our friend. That is, I may love my friend because of the pleasure I get out of her, or because of the ways in which she is useful to me, or because I find her to have a virtuous character. Given the involvement of love in each case, all three kinds of friendship seem to involve a concern for your friend for his sake and not for your own.
There is an apparent tension here between the idea that friendship essentially involves being concerned for your friend for his sake and the idea of pleasure and utility friendships: how can you be concerned for him for his sake if you do that only because of the pleasure or utility you get out of it? If you benefit your friend because, ultimately, of the benefits you receive, it would seem that you do not properly love your friend for his sake, and so your relationship is not fully one of friendship after all. So it looks like pleasure and utility friendships are at best deficient modes of friendship; by contrast, virtue friendships, because they are motivated by the excellences of your friend’s character, are genuine, non-deficient friendships. For this reason, most contemporary accounts, by focusing their attention on the non-deficient forms of friendship, ignore pleasure and utility friendships.
As mentioned in the first paragraph of this section, philia seems to be the kind of concern for other persons that is most relevant to friendship, and the word, ‘philia,’ sometimes gets translated as friendship; yet philia is in some ways importantly different from what we ordinarily think of as friendship. Thus, ‘philia’ extends not just to friends but also to family members, business associates, and one’s country at large. Contemporary accounts of friendship differ on whether family members, in particular one’s children before they become adults, can be friends. Most philosophers think not, understanding friendship to be essentially a relationship among equals; yet some philosophers (such as Friedman 1989; Rorty 1986/1993; Badhwar 1987) explicitly intend their accounts of friendship to include parent-child relationships, perhaps through the influence of the historical notion of philia. Nonetheless, there do seem to be significant differences between, on the one hand, parental love and the relationships it generates and, on the other hand, the love of one’s friends and the relationships it generates; the focus here will be on friendship more narrowly construed.
In philosophical accounts of friendship, several themes recur consistently, although various accounts differ in precisely how they spell these out. These themes are: mutual caring (or love), intimacy, and shared activity; these will be considered in turn.