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Regarding a recent letter to the editor, "Long live new friends" (Feb. 11) and the Star Tribune series "The Loneliness Cure," to which it was responding:

Our family too found the experience of moving to Minnesota in 1995 a bit daunting making friends. Like the letter writer, we attributed this condition to people having their own social group. We shouldn't take this personally because small, tight social groups are simply human nature.

Friendship is one of those puzzling nuances of human nature consuming philosophers, sages, academics all the way back to the ancients. One of the earliest to contemplate the nature of friendship was Aristotle, who around 340 B.C. wrote "Nicomachean Ethics." In this work, he set out to examine the nature of happiness and the virtues that form the basis of what he describes as the three types of friends, to wit: Friendships of Utility, which are of mutual benefit or usefulness; Friendships of Pleasure, which exist between you and those whose company you enjoy, and Friendships of the Good, which are based on a mutual appreciation of the virtues that the other party holds dear.

Friendships of the Good are the highest form of friendship, perfectly based on virtue and good, and are possible only between "good people similar in virtue." Rather than being short-lived, these relationships endure over time, and they take time and trust to build. According to Aristotle, there is a small number of people with whom one can sustain this type of relationship — less than a handful.

What's interesting about the nature of friendship is that psychologists tell us that today we have some three to five people that are our truest, closest friends; the same number of such friends Aristotle claimed we had 2,364 years ago. It may well be a universal law of human nature that we have a capacity limit when it comes friendships. This phenomenon was borne out by British anthropologist Robin Dunbar, who created the idea of "Dunbar layers," in which individuals could have no more than about 150 people in their social universe, layered according to the strength of emotional ties. Individuals, he says, generally have up to five people in the closest layer. The next closest layer contains an additional 10, the one beyond that an extra 35, and the final group another 100. So cumulatively, the layers contain five, 15, 50, and 150 people.

Applying the Aristotelian model to the Dunbar model would indicate three to five Friends of the Good, and 145 or so Friends of Utility and Friends of Pleasure. The former are those who can be considered the perfect, steadfast friends, while the latter two are those transitory friends who come and go throughout one's life.

So to for those moving to Minnesota, hang in there. It'll take some time to break into the circle of Friendship of the Good. In the meantime enjoy the companionship of the Friendship of Utility and Pleasure.

Joseph Tilli, of Wayzata, is a marketing consultant.