Arther Koestler coined the word "holon". It means "whole" in Greek. He then built a theory around this concept.
He observed that nature is architected with a series of parts that were both whole unto themselves and part of a larger whole.
He calls a holonic structure a "holarchy".
Holons are formed when they hold a series of smaller holons that have formed a relationship pattern that is self-sustaining and resilient. They then go on to form relationship patterns with other holons to form larger wholes larger than themselves. A holon exists in a dynamic tension between its sub-patterns and its meta-patterns forming complex self-regenerative Autopoietic Systems.
Holonic patterns lie at the heart of complex system theory and are essential for us to understand the nature of Pattern Languages.
If any part of the system breaks down and no longer supports the behavior of other parts of the system, the entire system breaks down. Cancer is an example of a systems destructive dysfunction.