The world, or at least the parts of it the Health Guardian is trying to understand, is organized in subsystems aggregated into larger subsystems, aggregated into still larger subsystems. This is the environment we find ourselves in. A cell in your liver is a subsystem of an organ, which is a subsystem of you as an organism, and you are a subsystem of a family, an athletic team, a musical group, and so forth. These groups are subsystems of a town or city, and then a nation, and then the whole global socioeconomic system that dwells within the biosphere system. This arrangement of systems and subsystems is called a hierarchy. Each level of that hierarchy consists of internal and external environments. It’s the Health Guardian’s challenge to understand, help maintain, and even control the holistic system and all the subsystems as well.

 In hierarchical systems, relationships within each subsystem are denser and stronger than relationships between subsystems. Everything is still connected to everything else, but not equally strong. The cells that constitute the liver are in closer communication with each other than they are with the cells of the heart.