Why do some things hold together while others fall apart? A human being. A marriage. An organisation. A society. Even a civilisation. Each faces the same fundamental challenge: how to remain whole while responding to a world that is continually changing. In The Coherence Principle, Richard Barrett proposes that everything that endures depends upon three conditions: Differentiation — Integration — Openness to Correction The parts must be sufficiently different to contribute their distinct capabilities. They must be sufficiently integrated to function as a whole. And the whole must remain open to correction by realities it does not control. When these conditions are present, people, organisations and societies can adapt and flourish. When integration is lost, they fragment. When openness is lost, something more deceptive can occur: a system may appear strong and united while becoming increasingly disconnected from reality. Drawing on more than forty years of work with individuals, leaders and organisations, Barrett explores how coherence is created, how it is lost, and what is required to restore it. At a time when people, organisations and societies are experiencing increasing fragmentation, The Coherence Principle offers a different way of understanding what is happening — and a practical framework for what we might do about it. Perhaps the most important question is not why things fall apart. It is why anything remains whole.