Public health seeks to advance the common health as the common good, standing for policies that improve health status, reduce health disparities, lower rates or early or premature death. This community as democratic purpose.
The community as differing views, as opening up different ways of thinking about problems. Because of William Haddon, Jr., and Ralph Nader, we think about highway traffic safety differently, as problems not with bad drivers, accidents, and so forth but as 'preventing damaging injury exchanges'.
Community offers more points of intervention: agent, hosts, and environment. Safer cars prevent damaging energy exchanges (agents); protect hosts with passive and active design (seat belt laws, safer highways, fewer road hazards like rigid, sharp structures, and so forth.
We enlarged the circle of responsibility, creating more people and options for prevention: car manufacturers, highway designers, passengers, ambulance personnel, emergency medicine skills, and so forth. Collective action often requires democratically imposed rules for us.