You may have perhaps wondered why certain systems, like well-running machines or the world's ecosystems, function so seamlessly? Well, resilience is a major factor in a system's capability to conform to changing conditions.

That is because resilience is a system's flexibility, or how well it recovers from a transition. The resilience of any given system is the result of its structure as well as its feedbacks, which work in multiple ways, directions, and even varying time scales. Let's look at the human body as an example. It can defend itself from invading forces, tolerate a range of temperatures, adapt to changes in the food supply, reassign blood, and even repair bones.

But people often do not value the importance of resilience, sacrificing it to things like productivity or comfort to the point where the system collapses. As an example, the mining industry utilize natural resources for profit but as a result of irresponsible mining, the environment has started to become irreparably damaged.

However, resilience is not the only defense available to systems; some of them can also self-organize. This means that they can diversify, learn, evolve, and build on their own structure: a single, fertilized ovum has the ability to become a fully grown human being.

So, as systems create new, increasingly more complex structures, they naturally organize themselves based on a logical hierarchy. In fact, everything on earth can be divided into subsystems that form larger subsystems, which produce larger ones still. A cell in your liver is a subsystem of the organi itself, which is a subsystem of you, and you're a subsystem of a family, which is a subsystem of a nation, and so on and so forth.

But why hierarchies?

Because they reduce the level of information any given section of the system has to handle. As an example, since liver cells know how to decompose toxins, heart cells don't need to.