Donella H. Meadows's Thinking in Systems is a primer on systems thinking, drawing on various disciplines and offering accessible explanations of complex systems. The book uses examples and diagrams to illustrate core concepts like feedback loops (reinforcing and balancing), stocks and flows, and delays. Meadows explores how these elements interact to produce surprising system behaviours and discusses common system traps, such as the tragedy of the commons and escalation. Finally, it suggests leverage points for intervening in systems to achieve desired outcomes, emphasizing the importance of understanding system structure and resisting the illusion of control.