In the five Confucian relationships, friendship is the odd one out. Why is it there?
Its coordinates: 6.19 Philosophy of Love and Friendship
My students memorise Mencius's list of the five relationships for exams: affection between father and son, rightness between ruler and minister, distinction between husband and wife, proper order between elder and younger, and trust (xin) between friends. They memorise it and never ask the obvious question. Four of the five are hierarchical and largely unchosen. Friendship is the only one you choose, and the only one between people who may be equals. What is it doing in the list?
I have two guesses.
One is that friendship is where you practise virtue without the support of a fixed role. With your father you know your part. With a friend you have to work out what trust requires each time. The Analects opens with the joy of friends arriving from afar, and later Zengzi examines himself daily on whether he has been trustworthy to his friends. Friendship seems to be a test of character in a way roles are not.
The other is that friendship is how a scholar's moral life extends beyond the family, the bridge between the household and the wider world.
Both remind me of Aristotle's friendship of virtue, where friends wish each other well for their own sake and improve each other. But I'm wary of collapsing the two. Aristotle's friends are equals in the polis; Confucian friends may still be older and younger, and that matters.
How do others read friendship's place in the list? And are there traditions where friendship is more central, or less?