A while back I read an essay that contrasted communities of duty against those of choice. It was interesting, and from a liberal perspective made the first argument against gay marriage that made any sense to me (not that it was convincing, but at least it made sense), but in trying to understand, it missed the point.
The point is not that some people have communities and relationships formed by duty and some that are created by choice, but that some people are responsible and some people appear to be ruled by caprice and whim.
There may be some issue of duty in terms of family members caring for family members, but it is more about being responsible. There may be some duty in members of the church caring for each other, but it is more about love and responsibility. The same is true of those who participate in the children's medical clinic we have locally. I guess some one who volunteers feels a duty, but mostly they are just responsible and they chose compassion.
The network of relationships that forms any community has a great deal of choice, but it is founded on responsibility, not duty. It is not as if there is some lifeless, drudge filled "red" state of mind driven my grudging duty that should be juxtaposed against the glorious freedom of choice and the blue light of freedom.
Rather, many people see it as a choice between being responsible and being ruled by caprice and whim. Aesop got it. Bruce Hafen understood it (see his "love is not blind" speech). But until someone understands that what is going on is perceived as a clash between responsibility and arbitrary caprice rather than a clash between duty and choice, they will not understand and will only insult instead of engage.