Friendship is notoriously difficult to define. For Aristotle, friendship, or philia, is a virtue which is "most necessary with a view to living … for without friends no one would choose to live though he had all other goods." For a person to be friends with another, he says, "it is necessary that [they] bear good will to each other and wish good things for each other, without this escaping their notice."
A person may bear good will to another for one of three reasons: that he is good (that is, rational and virtuous), that he is pleasant, or that he is useful. While Aristotle leaves room for the idea that relationships based on advantage alone or pleasure alone can give rise to friendships, he believes that such relationships have a lesser claim to be called friendships than those that are based partly or wholly on virtue. "Those who wish good things to their friends for the sake of the latter are friends most of all, because they do so because of their friends themselves, not coincidentally."
Friendships that are based partly or wholly on virtue are desirable not only because they are associated with a high degree of mutual benefit, but also because they associated with companionship, dependability, and trust. More important still, to be in such a friendship is to exercise reason and virtue, which is the distinctive function of human beings, and which, in Aristotle’s system, amounts to happiness.
In Plato’s Lysis, Socrates says that he should ‘greatly prefer a real friend to all the gold of Darius’, thereby signifying not only that he places friendship on the same high pedestal as philosophy, to which he has devoted (and will sacrifice) his life, but also that the kind of friendship which he has in mind is so rare and uncommon that even he does not possess it. For Plato, friendship ultimately escapes definition because is more a process than an object. Real friends seek together to live truer, fuller lives by relating to each other authentically and by teaching each other about the limitations of their beliefs and the defects in their character, which are a far greater source of error than mere rational confusion. For Socrates as for Plato, friendship and philosophy are aspects of one and the same impulse, one and the same love: the love that seeks to know.
If friendship is hard to define, love is even more so, not least because there are several types of love. Most present in modern minds is eros, which is sexual or passionate love. In Greek myth, eros is a form of madness brought about by one of Cupid’s arrows. The arrow breaches us and we "fall" in love, as did Paris with Helen, leading to the Trojan War and the downfall of Troy. In modern times, eros has been amalgamated with the broader life force, something akin to Schopenhauer’s will, a fundamentally blind process of striving for survival and reproduction. Eros has also been contrasted with Logos, or Reason, with Cupid depicted as a blindfolded child.
Until perhaps the 19th century, people thought of love more in terms of agape than eros. Agape is universal love, such as the love for strangers, nature, or God. Also called charity by Christian thinkers, it can be said to encompass the modern concept of altruism, defined as unselfish concern for the welfare of others. Agape helps to build and maintain the psychological, social, and, indeed, environmental fabric that shields, sustains, and enriches us. Given the increasing anger and division in our society, and the state of our planet, we could all do with more old-fashioned agape.
There are also other types of love, most notably storge and pragma. Storge, or familial love, is the love between parents and their children. More broadly, it is the fondness born out of familiarity or dependency and, unlike philia or eros, does not depend on our personal qualities. People in the early stages of a romantic relationship often expect unconditional storge, but find only the objectifying eros, and, if they are lucky, a certain degree of philia. Over time, eros often mutates into storge and, if we are lucky, there is some philia as well.
Pragma is a kind of practical love founded on reason or duty and one’s longer-term interests. Sexual attraction takes a back seat in favor of personal qualities and compatibilities, shared goals, and making it work. In the days of arranged marriages, pragma must have been very common. Although unfashionable, it remains widespread, most visibly in certain high-profile celebrity and political pairings.
So where is the boundary between friendship and love? Actually, I think that the higher kind of philia that is based partly or wholly on virtue has a much stronger claim to the name of love than eros, not least because eros is much more selfish and objectifying.
Friendship is not different from love, but the best kind of love.
And if we can be friends with someone we are attracted to, then so much the better—so long as it works for, and not against, the friendship.
Neel Burton is author of For Better For Worse and other books.