"Closed friendships are upsetting initially because they do not offer friendliness to outsiders, but open friendships are far more disruptive because they invite outsiders in. Life at work, in the neighborhood, at home, in the schoolyard, or among our best companions and allies might go on smoothly and in a friendly way without the intrusion of friendships. Friendliness is safe and stable, and therefore more common and acceptable than captivating friendships. Lively friendships form when two or three in the neighborhood or workplace start thinking and seeing things together. They start talking and become captivated by an idea or vision of what they can do and where they can go together. They will begin to form a place in the world together that is deeper and richer than it is when each goes about his or her business alone.
Friends start to do more than just spend time or cooperate at work. They start to live, struggle, and move forward side by side with the same way of envisioning the future. Friends conspire. They plan. They want to make a difference. They seek a goal that is beyond each and attainable only together. Together, they are able to imagine a different kind of world, and together they are able to act in it. Such friendship can be closed in upon itself or open to any who are captivated by the same journey. Friendship brings either withdrawal or an offer that will change us. When friendship brings an offer of hospitality, it is an intrusion upon our safe and smooth-running world."
David Matzko McCarthy in The Good Life, pages 36-37.