One of the concepts at the heart of this enterprise is a conception of the common good. It is unfortunate that some economists have tried to create distinctions intended to dismiss the idea that we share a life together, one that is intrinsically tied both to who we are and to other people from whom we derive our identity and our place in the world. The common good is something we share, but it not always inclusive, common, or good.
To be free to express ourselves means that we do not have to worry about being injured by people, but there are limits to what we can do, what we can say, and what we can claim as our own. What we say or do does not happen in a vacuum in which we are the only inhabitants. We share our lives, whether we choose to or not, with other people and with the legacies of those who came before us, with the decisions they made about the world we entered when we were born. In our relationships, transactions, and interactions there is something of our ancestors. The fact that we survived infancy is a testament to the fact that we are dependent on other people for our survival. Our inheritance is not always something that we appreciate or accept when we have the opportunity to reflect upon as adults. Some of us were born to people who provided nurturing environments and experiences that helped us develop into strong, capable people. Others were less fortunate in their condition, but we often find ourselves in need of assistance from others in ways that we could never anticipate.
In a society where there are many people who are willing and capable to provide help when needed, one could be confident in the comfort of good neighbors, member of our religious communities, our families and friends. The community that is created by the mutual understanding of our responsibilities toward each other is what we depend upon for ourselves. Even if one does not accept such obligations as a divine stricture, it is still reasonable to argue that societies cannot exist without an implicit understanding that mutual aid is a factor in our collective success.
In all successful societies, where people generally live long, happy, and productive lives, there is also a high degree of trust and confidence in the institutions of society. We need to remember that these conditions require effort and are not magically established with no further need for maintenance. Without the maintenance of these conditions, we are all poorer and less able to live as well as we might if we make it our business to keep faith with one another. To think about this more deeply, it's worth considering the work of game theorists who have simulated how cooperation can be modeled. Hint: Keep an eye on the payoff structure.