“True friendship is caring for others without calculating how much you have given and received.”

BarcelonaWhy do we make friends with some people and not others? Can a friendship survive time and distance? Can we live without friends? Since ancient times, the concept of friendship has occupied a central place in people's lives.Epic of Gilgamesh is already the main topic, while in theNicomachean EthicsAristotle devotes two entire books to defining the different forms of friendship. And before him, Plato and Xenophon, in their Symposiums, portray many of the feelings that friendship evokes in us.

It is precisely these banquets that have inspired neuroscientist Mariano Sigman and writer Jacobo Bergareche to write Friendship (Debate, 2025). This is a shared essay with which these two friends and neighbors have overcome one of the many tests that, as Aristotle said, builds a friendship throughout life. "When we first started, we used to say ironically that we might end up arguing while writing a book about friendship," they say, laughing. Far from it, the essay has strengthened their bond.

In its pages, emulating one of the banquets of antiquity, they meet with all kinds of people, from doctors, military personnel, comics, and actors, to teenagers and octogenarians, to reflect on their idea of friendship, in addition to investigating what thinkers like Montaigne and Pluta had to say. "Each one had a very different concept of what a friendship is like and how it's built," Bergareche asserts. Quite a few people have explained to them how friendship is born as love at first sight, while some claim that, at first, they didn't like the other person. "There's no one way to define how you make a good friend," he continues. What is clear is that chemistry plays an important role. "We mustn't forget that, at heart, we are mammals," Sigman adds.

There are friendships that only exist in certain settings and times, such as coworkers or friends you only meet to do an activity, such as cycling. These are friendships that, beyond the bond and environment that unites them, don't last long when interacting in other settings and times. This doesn't mean they're any less valid. "Almost all friendships require shared activities, even if it's just sitting in a bar and talking," Bergareche clarifies.

Various friendships

One of the questions raised at the book banquet is whether you can be a friend of a family member. Is it the same type of relationship? "Family ties entail a series of obligations and hierarchies that don't apply to friends," the author reflects. However, many people claim to be friends with their parents, children, or even their partner. Others, however, believe that, precisely because of this underlying responsibility, it can't be considered a friendship. per se.

"There's an ideal of purity in friendship, but the reality is that it's fraught with interference, and learning to manage it is one of the key lessons," Sigman explains.

There are friendships that last seconds, some are asymmetrical, or that save lives. "We've heard stories of women who met in a nightclub bathroom and who, for a few minutes, gave each other refuge and companionship, even if they never saw each other again," explains Sigman. These are people who, over time, you still remember fondly and are grateful that they gave you a hand to overcome a difficult time. And sometimes, it's even necessary that you didn't know them before, to avoid overconfidence and prejudice. "Just as we eat fruits, vegetables, and legumes, we also need long-term friendships that know you very well, but also short-term friendships that have their purpose," she continues.

All friendships are equally necessary, and no two are quite like each other. "We want to care for others without having to pull out a calculator to see how much we've given and how much we've received. We want to care for others simply for the sake of making them feel good," Sigman continues.

Aristotle said that no one would want to live without friends, even if they had all the goods in the world. There are times, such as during adolescence or old age, when the company of others is more vital than ever. But what is clear is that a life worth living is one in which friends are never lacking.