(THE CONVERSATION) While most love songs are inspired by the joys and heartaches of romantic relationships, love between friends can be just as intense and complicated. Many people struggle to make and maintain friendships, and a falling-out with a close friend can be as painful as a breakup with a partner.

Despite these potential pitfalls, human beings have always prized friendship. As the 4th century B.C.E. philosopher Aristotle wrote: “no one would choose to live without friends,” even if they could have all other good things instead.

Aristotle is mostly known for his influence on science, politics and aesthetics; he is less well known for his writing on friendship. I am a scholar of ancient Greek philosophy, and when I cover this material with my undergraduates, they are astonished that an ancient Greek thinker sheds so much light on their own relationships. But maybe this should not be surprising: There have been human friendships as long as there have been human beings.

Here, then, are three lessons about friendship that Aristotle can still teach us.

1. Friendship is reciprocal and recognized

The first lesson comes from Aristotle’s definition of friendship: reciprocal, recognized goodwill. In contrast to parenthood or siblinghood, friendship exists only if it is acknowledged by both parties. It is not enough to wish someone well; they have to wish you well in return, and you must both recognize this mutual goodwill. As Aristotle puts it:”To be friends … [the parties] must feel goodwill for each other, that is, wish each other’s good, and be aware of each other’s goodwill.”

Aristotle illustrates this point with an early example of a parasocial relationship – a one-sided kind of relationship in which someone develops friendly feelings for, and even feels that they know, a public figure they have never met. Aristotle offers this example: A fan may wish an athlete well and feel emotionally invested in his success. But because the athlete does not reciprocate or recognize this goodwill, they are not friends.

This is as true today as it was in Aristotle’s time. Consider that you cannot even be Facebook friends with someone unless they accept your friend request. By contrast, you can be someone’s social media follower without their acknowledgment.

Still, it is perhaps more difficult today to distinguish friendships from parasocial relationships. When content creators share details about their personal lives, their followers may develop a one-sided sense of intimacy. They know things about the creator that, before the arrival of social media, would have been known by only a close friend.

The creator may feel goodwill toward her followers, but that is not friendship. Goodwill is not genuinely reciprocal if one party feels it toward an individual while the other feels it toward a group. In this way, Aristotle’s definition of friendship lends clarity to a uniquely modern situation.

2. Three kinds of friendship

Consider next Aristotle’s distinction between three kinds of friendship: utility-based, pleasure-based and character-based friendships. Each arises from what is valued in the friend: their usefulness, the pleasure of their company or their good character.

While character-based friendship is the highest form, you can have only a few such intimate friends. It takes a long time to get to know someone’s character, and you have to spend a lot of time together to maintain such a friendship. Since time is a limited resource, most friendships will be based on pleasure or utility.

Sometimes my students protest that utility relationships are not really friendships. How can two people be friends if they are using one another? However, when both parties understand their utility friendship in the same way, they are not exploiting but rather mutually benefiting one another. As Aristotle explains: “Differences between friends most frequently arise when the nature of their friendship is not what they think it is.”

If your study partner believes you hang out because you enjoy her company, while you actually hang out because she is good at explaining calculus, hurt feelings can follow. But if you both understand that you are hanging out so that you may improve your calculus grade and she her writing grade, you can develop mutual goodwill and respect for each other’s strengths.

Indeed, the limited nature of a utility friendship can be just what makes it beneficial. Consider a contemporary form of utility friendship: the peer support group. Since you can have only a small number of character-based friends, many people dealing with trauma or struggling with chronic illness do not have close friends working through these experiences.

Support group members are uniquely positioned to help one another, even if they have very different personal values and beliefs. These differences may mean that the friendships never become character-based; yet the group members may feel deep goodwill toward one another.

In short, Aristotle’s second lesson is that there is a place for each kind of friendship, and that a friendship works when there is a shared understanding of its basis.

3. Friendship is like fitness

Finally, Aristotle has something valuable to say about what makes friendships last. He claims that a friendship, like fitness, is a state or disposition that must be maintained by activity: As fitness is maintained by regular exercise, so friendship is maintained by doing things together. What happens, then, when you and your friend cannot engage in friendship activities? Aristotle writes:

“Friends who are … parted are not actively friendly, yet have the disposition to be so. For separation does not destroy friendship absolutely, though it prevents its active exercise. If however the absence be prolonged, it seems to cause the friendly feeling itself to be forgotten.”

Contemporary research backs this up: The state of friendship can persist even without friendship activities, but if this goes on long enough, the friendship will fade. It might seem that Aristotle’s point has become less relevant, as communication technologies – from postal service to FaceTime – have made it possible to maintain friendships across great distances.

But while physical separation no longer spells the end of a friendship, Aristotle’s lesson remains true. Research shows that, despite having access to communication technologies, people who decreased their friendship activities during the first year of the COVID-19 pandemic experienced a corresponding decrease in the quality of their friendships.

Today, as in ancient Athens, friendships have to be maintained by engaging in friendship activities.

Aristotle could not have imagined today’s communication technologies, the advent of online support groups or the kinds of parasocial relationships made possible by social media. Yet for all the ways in which the world has changed, Aristotle’s writing on friendship continues to resonate.

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