Friendship is as old as humanity itself. Roman orator Marcus Tullius Cicero once wrote, “Nature has no love for solitude, and always leans on some support; and the sweetest support is found in the most intimate friendship.”

Some of the ancient world’s greatest minds pondered the qualities of a good friendship. Modern society has also trained its empirical minds upon the question and found that friendship not only makes life more enjoyable, it also leads to greater health and longevity. 

One study found that walking up a hill with a friend makes it feel less steep. A meta-analysis of about 150 studies found that people with no friendships, or poor quality friendships, are twice as likely to die prematurely. 

The ancient philosophers of both East and West spoke of the ideal friendship as a journey toward self-perfection. 

The ultimate goal is to improve one’s character, and the deepest friendships exist between two good people striving toward this goal. “Iron sharpens iron,” the Bible tells us, and this is the effect one friend should have on another. 

The Chinese sage Confucius expressed similar ideas, according to Analects, a collection of teachings attributed to him. He named three characteristics of a good friend and three characteristics of a bad friend. A good friend is upright, sincere, and learned. A bad friend is devious, insincere, and superficial.

Friendship starts as a natural affinity for one another, but it is sustained by choice. 

You can’t choose your family, but you can choose your friends. That choice not only reflects who you are, it also influences who you become. A friend is “another self,” Aristotle said in “Nicomachean Ethics.”

Of course, friendship isn’t only about serious personal growth. It’s also about dancing to the same tune, being able to talk freely together, and sharing in the many joys of life.  

The following is a guide to friendship—qualities to seek in a friend, and qualities to embody as a good friend. 

Walking up a hill with a friend makes it feel less steep. (PeopleImages/Shutterstock)

Build a Friendship on Solid Ground

Some friends have fun together, but the ground quickly shifts when people or circumstances change. For example, you may enjoy playing tennis with a friend, but if that friend is injured and no longer plays, will the friendship last? 

Many ancient sages and modern scientists would agree that the tennis friend still has value. In sociology-speak, this would be called a “weak-tie” friendship. But when seeking deeper, lasting friendships, mere pleasure in transient pursuits does not form the most solid foundation. 

Friendships may also be weak when built on harmful pleasures. Perhaps two people enjoy gossiping together or drinking together in excess. If one of the friends stops this behavior, the friendship likely dissolves.

Friendships based on material benefits—such as helping each other acquire clients—are also “weak ties” and may fall apart quickly.

Aristotle called such friendships incidental. 

“Those who love for the sake of pleasure do so for the sake of what is pleasant to themselves, and not in so far as the other is the person loved but in so far as he is useful or pleasant. And thus these friendships are only incidental,” he said. 

Friendship must spring from the love and appreciation of a friend’s lasting, fundamental character.

Be Virtuous, Seek Virtue

Virtue is the most solid ground upon which to build a friendship, according to many ancients. 

“[Virtue] is the parent and preserver of friendship, and without it friendship cannot possibly exist,” Cicero said in “On Friendship.” “Friendship can only exist between good men.” 

Of course, there are many people who lack virtue and share friendship in vice, but as previously mentioned, those could be considered incidental friendships. 

“Wicked men have no steadfastness (for they do not remain even like to themselves), but become friends for a short time because they delight in each other’s wickedness,” Aristotle wrote. 

Plato discussed the kind of friendship found in a band of thieves: They work together toward a common end, and thus there’s a certain justice among them. They don’t wrong each other up to a certain point—but they’re more likely to wrong each other. 

“Nothing inspires love, nothing conciliates affection, like virtue,” Cicero wrote. 

Confucius also urged people to find friends of “superior character.”

“Friendship can only exist between good men,” Cicero said in “On Friendship.” (Rawpixel.com/Shutterstock)

Be Loyal

Three famous friends from China’s Three Kingdoms period (2nd–3rd century CE) exemplify the quality of loyalty. The friends—Guan Yu, Liu Bei, and Zhang Fei—swore an oath of friendship and stayed true to it through thick and thin.

The warlord Cao Cao showered Guan Yu with gifts and titles, trying to win his loyalty. But Guan Yu eschewed the favors and returned to Liu Bei’s side as soon as he could. Guan Yu even fought through five army checkpoints to get to him.

Zhang Fei similarly stuck by Liu Bei through many challenges, and his deep grief after Guan Yu’s death showed his great loyalty to him.

We see a similar oath of friendship upheld in the Bible, between Jonathan and David. Jonathan was a prince, and David a shepherd—the young shepherd who famously killed the giant Goliath with his slingshot by putting his faith in God. 

David outshadowed Jonathan in many ways, and even took his place as heir to the throne. Jonathan could have become jealous and malicious, but even when his father, King Saul, turned on David, Jonathan stayed true to his friend.

Even children as young as 3 use loyalty as an indicator of who their friends are, according to research published in the Journal of Experimental Child Psychology. For example, they expect their friends to share with them more than with non-friends. When presented with vignettes, they can identify characters who are friends based on loyal actions. 

The study cited a body of previous research showing three important characteristics of friendship: propinquity (close proximity), similarity, and loyalty. 

The study noted that loyalty may be the most important of the three. You can have long-distance friendships or friends who are dissimilar to you, “but if a person’s friend is consistently disloyal, the friendship would likely dissolve.” 

Don’t Ask Friends to Do Wrong

Loyalty may have its limits, however. Cicero and others warned against friends who ask you to do wrong in the name of friendship.

“We may lay down this rule of friendship: neither ask nor consent to do what is wrong. For the plea ‘for friendship’s sake’ is a discreditable one,” Cicero wrote in his treatise “On Friendship and Old Age.” 

He gave the ancient Roman equivalent of, “If your friend jumps off a bridge, will you do it too?” 

Gains Blossius said that he was so loyal to his friend Tiberius Gracchus that Gracchus’s word was like law to him, and he must follow it. 

“Even if he had wished you to set fire to the Capitol?” Cicero’s narrator, Laelius, asks.

Aristotle expressed a similar view in “Nicomachean Ethics.” 

“Neither ask nor give base services, but (one may say) even prevent them; for it is characteristic of good men neither to go wrong themselves nor to let their friends do so.”

Friends may not be equals in social status, but they meet as equals in what matters more than outward fortune. (New Africa/Shutterstock)

See Your Friends as Equal, Don’t Keep Score

“Friendship is equality; equality is friendship,” said Pythagoras, according to Iamblichus’s “Life of Pythagoras,” written in the 4th century CE.

Iamblichus noted that Pythagoras—a Greek philosopher and polymath for whom “all things accord in number”—often spoke to his followers about this equality in friendship. 

The Bible’s David and Jonathan were not equals in social status, but were equal in virtue and characteristics more fundamental than outward fortunes. 

“Equality and likeness are friendship, and especially the likeness of those who are like in virtue,” Aristotle wrote.

Cicero warned, however, against the tendency to expect exact equality between friends in terms of how much they love each other or how they show their love. 

Some people act as though “the object were to have an exact balance in a debtor and creditor account. True friendship appears to me to be something richer and more generous … not to be so narrowly on its guard against giving more than it receives.”

Be Selective

You may have 500 Facebook friends, but you’ll likely only have two or three close friendships. 

Aristotle wrote, “One cannot be a friend to many people in the sense of having friendship of the perfect type with them, just as one cannot be in love with many people at once. … One must, too, acquire some experience of the other person and become familiar with him, and that is very hard.”

It takes time to establish deep roots of friendship and find each other lovable and trustworthy. 

“Men cannot know each other till they have ‘eaten salt together,’” Aristotle wrote, meaning they must share many meals over the course of time. 

Cicero likewise said, “Affection is ever shared by two persons only, or at most by a few.” Deep affection between friends is “concentrated and confined to so narrow a sphere.”

Research from Frontiers in Psychology also finds that individuals report an average of three close friends. 

The British anthropological biologist Robin Dunbar famously identified the number of stable social relationships one may have. The so-called “Dunbar’s Number” is 150. He broke that down into different classes of relationship, with your inner circle limited to five, including family and your closest friends. You may have 15 in the second tier of friendship.

“It is natural that such friendships should be infrequent; for such men are rare,” Aristotle said. “A wish for friendship may arise quickly, but friendship does not.”

“Men cannot know each other till they have ‘eaten salt together,’” Aristotle wrote, meaning they must share many meals over the course of time. (Jelena Zelen/Shutterstock)

Be Generally Pleasant, But You May Share Sorrows

Aristotle said “sour” people are not likely to have friends, as it is painful to be with them. 

“No one can spend his days with one whose company is painful, or not pleasant, since nature seems above all to avoid the painful and to aim at the pleasant.”

Friends must, however, be willing to endure some unpleasantness. Cicero admonished the Sophists who say one should avoid friendship so as to avoid taking on the anxieties of others.

He argued that some anxiety comes with virtue—the brave are distressed by cowardly action, the just distressed by injustice, the temperate distressed by depravity.

“We conclude then that mental pain which we must often encounter on a friend’s account is not of sufficient consequence to banish friendship from our life, any more than it is true that the cardinal virtues are to be dispensed with because they involve certain anxieties and distresses,” wrote Cicero. 

Be a Good Confidante and Adviser

The Roman Stoic philosopher Lucius Annaeus Seneca said friends should be able to speak with each other as with themselves.

“Ponder for a long time whether you shall admit a given person to your friendship; but when you have decided to admit him, welcome him with all your heart and soul. Speak as boldly with him as with yourself,” Seneca wrote in his Moral Epistle “On True and False Friendship.”

In this epistle, Seneca expressed shock at hearing a man call another a “friend” and yet not speaking freely with him, seeking to hide his thoughts.

Being able to speak freely, and in confidence, with a sympathetic listener is tied to many core functions of friendship, according to a 2023 paper published in the journal Frontiers of Psychology.

A good confidante provides emotional support and security, intimacy, and self-validation. Regarding “self-validation,” friends provide “encouragement and confirmation, thus helping … [one] maintain a positive self-image.” 

Most people don’t like to open their hearts to another only to face scorn and criticism. “Don’t criticize, condemn, or complain,” is principle No. 1 in Dale Carnegie’s 1936 book “How to Win Friends and Influence People.”

But he doesn’t suggest being an unconditional yes-man either. The only way to influence a friend’s thinking is to listen with interest and curiosity, then speak with tact. He cites ancient wisdom of the East and West. Socrates didn’t tell people they were wrong, Carnegie said. Socrates instead asked them questions to which they would answer “yes,” and thus he drew them toward a conclusion.

Carnegie also quoted a Chinese proverb: “He who treads softly goes far.”

On the other hand, Cicero said advice may need to be forceful at times for a friend’s own good.

“Let us have the courage to give advice with candor,” he said. “In friendship, let the influence of friends who give good advice be paramount; and let this influence be used to enforce advice not only in plain-spoken terms, but sometimes, if the case demands it, with sharpness; and when so used, let it be obeyed.”

Plutarch, a Greek philosopher of the 1st–2nd centuries CE, also advised that a genuine friend sometimes must cause discomfort, but friendship isn’t about constantly finding fault. You shouldn’t be delighted to find your friend’s shortcomings. 

In his essay “How to Tell a Flatterer from a Friend,” Plutarch said that one must neither seek to please nor to displease a friend, but rather to say what will benefit that friend. 

Being able to speak freely, and in confidence, with a sympathetic listener is tied to many core functions of friendship. (Ulza/Shutterstock)

Make Music and Soup Together

Friendship isn’t all serious pursuit of spiritual perfection or leaning on each other for emotional support. It’s also about sharing life’s many joys. 

Confucius used analogies of cooking and music to describe friendship. The harmony of two friends is like two strings plucked on an erhu. It’s also like the blending of complementary ingredients into a good soup. And friendship brings the same kind of pleasure as a beautiful tune or a delicious dish.

In the Liezi—a 5th century Daoist text attributed to Lie Yukou—a story of two friends and the musical instrument, the zither, illustrates this harmony. 

A blind zither player named Yu Boya refuses to ever play again after the death of his friend Zhong Ziqi. He believed only Zhong could fully appreciate his music.

Birds of a Feather or Opposites Attract?

It seems the jury is out on whether friends should be similar or different from each other. 

Aristotle pondered the question in “Nicomachean Ethics” and cited several sayings of his time along the lines of “opposites attract,” such as “parched earth loves the rain,” and “from different tones come the fairest tune.”

In “Phaedrus,” Plato wrote, “Similarity begets friendship.”

Several modern studies have also found that people prefer friends who are similar to themselves, according to a review in the Journal of Experimental Child Psychology.

Confucius said, according to Analects, that one should seek harmony, allowing for differences that complement each other. One should not necessarily seek uniformity or sameness. 

Confucius said that one should seek harmony, allowing for differences that complement each other. (Inside Creative House/Shutterstock)

Friendship Adds to Quality of Life

There is much more to be said about friendship and the age-old questions of how to seek and provide it. What about friendship between husband and wife, or mother and daughter, or brothers? 

These are friendships as well, to be sure, and an understanding of friendship in general may apply to other relationships in one’s life. Familiar dynamics add other dimensions to these friendships. 

After reading a good book, you may feel its characters are your friends. The Confucian philosopher Mencius famously talked about “making friends with history.” Meaning, you may befriend worthy people from antiquity.

British author C.S. Lewis included a chapter titled Friendship in his book “The Four Loves.” He said friendships help us “not to live, but to live well.”

“Friendship is unnecessary, like philosophy, like art, like the universe itself. ... It has no survival value; rather it is one of those things which give value to survival,” he wrote.