The concept of the common good is that all members in a given community share the benefits of being part of that community. This does not mean the monastic or communal type of arrangements. The simple meaning is that within a community (nation, state, and neighborhood) that individuals work towards a common purpose of improving the welfare of all members of that community. It is not wealth redistribution; it is not loss of freedom to pursue individual goals and objectives. It stands to reason that the effort of the variety of skills and enterprises benefit everyone. The common good does not eliminate individual or subgroup disadvantages. The simple and pure understanding of this idea is that individual efforts and purposes include building and growing everyone within its domain.
Jim Wallis has a healthy insight into this idea in the Time article (April 4, 2013). He stresses this ancient idea where the communities survive and progress thru this idea of a moral compass. The proven concept that team work and diversity of ideas is the basis of sound and sustainable progress. Focusing on the betterment of our neighbors is the reason the human species were able to leave the caves for ordered social structures. It is not something that happens by magic, but by the decisions and changes the majority make on a daily basis.
The major threat to the common good is fear. Fear that intensifies when people feel alone and isolated. Disconnection from the social order is the basis of fear and anxiety with all of the dynamics of flight-or-fight responses. Fear is most prominent during a changing cultural evolution. While time is the basis of change, the pace of change breeds disorder. The ultimate challenge to each individual and society in general is the ability to overcome the need for self-protection. The group is always stronger than the individuals are. Changing chaos to order requires the collective effort of the entire community.