Friendship as Love and Brotherhood and Friendship as Play, Complicity and Shared Joy

We like to place friendship in its highest stage. «Nobody would choose to live without friends even if he had all the other good things of life», says Aristotle, illustrating our penchant to drive friendship to its top and most demanding expressions, where it mimics love.

Friendship may indeed be a form of love and fraternity in the deepest sense of the words. There are many definitions of friendship in these very terms:
 

A faithful friend is the medicine of life

Bible, Ecclesiastes
Friends cannot lend or give anything to each other. (…)  Everything should belong to each of them. 
(…)

The union of two such friends being truly perfect, it causes them to lose the sense of such duties, and to detest and banish as between themselves those words implying separation and difference – benefit, obligation, gratitude, entreaty, thanks, and their like.Montaigne, 1533-1592, French writer, Essays

And yet friendship may also not involve love. Currently, friendship stands at a less demanding stage: the one of conviviality, of social interactivity, of shared joy. 

This second view of friendship doesn’t truly diminish it. We need our spaces of conviviality, of play, of joy, of social interaction, as much as we need love. Our nature doesn’t dispense it.

Friendship feeds on communication.
Montaigne, 1533-1592, French writer, Essays

Human beings also live of music, contemplation, flowers, smiles.

E. Morin, French philosopher and sociologist, Método V

To like and dislike the same things, that is indeed true friendship.Sallust, 86-35 b.C., Roman historian, Jughurta

To share the happy and sad moments, to confess secrets and intimate projects, all these is a major part of friendship.A. Rievaulx, 1109-1167, French religious, L'Amitié spirituelle

But that doesn’t alter much our way of seeing things. We persevere seeing friendship as having high standards of brotherhood, complicity and help. And when these last dimensions – very close to love, or mingled with it – fail, we regret it, and consider the very fact as treason:

What is commonly called friendship isn’t but a society, a combination of interests, a change of good intentions; a commerce, where self-interest wants to win something.Rochefoucauld, 1613-1680, French writer, Maxims

My dear friends, there is no such thing as a friend.E. Kant, 1724-1804, German philosopher, Fundamentos da Filosofia dos costumes

Extreme and delicate friendship can be wounded by a thorn of a rose.S. Chamfort, 1740-1794, French writer, Maximes et pensées

As love, friendship also involves jealously and susceptibilities.

Eric Blondel,  French writer, L'Amour   
A true friendship is as rare as a black swan.E. Kant, 1724-1804, German philosopher, Fundamentos da Filosofia dos costumes