"Today it seems to me that love and friendship play a central role and that without them even the noblest achievements and the most fundamental principles remain pale, empty, and dangerous.
And when speaking of love, I don't mean an abstract commitment such as "love of truth" or a "love of humanity," which, taken by themselves, have often encouraged narrow-mindedness and cruelty. Nor do I mean emotional fireworks that soon exhaust themselves. I can't really say what I mean, for that would delimit a phenomenon that is a constantly changing mixture of concern and illumination.
Love lures people out of the limited "individuality," it expands horizons, and it changes every object in their way. Yet there is no merit in this kind of love. It is subjected neither to the intellect nor to the will; it is the result of a fortunate constellation of circumstances. It is a gift, not an achievement."
Update : Here are some thoughts by Rawls on "Fraternity" but i'm not sure it can be seriously applied society-wide for the obvious reason of man's fallenness.