o acquire these habits and dispositions, we need settings where they can be practiced, where we can literally see our diversity, where we belong but others belong as well, people who are different from us but with whom we are interdependent precisely because we live together. In other words, we need changes in our rhetorics that will help us practice better public problem-solving, and we need changes in our environments that will bring us closer together so that such problem-solving is unavoidable
This is the whole point of the book in one sentence.