ESSAY · COMPLEXITY & HUMAN SYSTEMS Medicine has always been better at fixing broken parts than understanding living systems. After thirty years as a GP, I have come to believe there is a richer way to understand what is happening when people get stuck — and it comes from complexity science. Imagine two people sitting in a GP’s waiting room. Both feel exhausted, sleep poorly, and struggle with low mood. Both will be asked roughly the same questions. Both may leave with broadly similar advice....