I have been studying complexity theory a lot recently (as part of my own research) and read dozens of books about it and all kinds of vaguely related subjects. As such, there wasn’t much in this book that was completely new to me. In spite of this, *Thinking in Systems* felt like an eye-opener that brought many things together very neatly. It also put some things I’ve known for an even longer time — from reading about sociology, say — into a neat general framework. So many things are systems that operate under their own laws, but we may imagine them to be much simpler to change than that, or to be directly based on individual choices in case of social systems. So this book perfectly plausibly brings thermostats and social inequalities under the same general framework.

Part one, which explains the basics of how to model systems, is written in a refreshingly clear way that hides the essential mathematics but doesn’t remove it. As a reader, you don’t have to so much as look at off-puttingly complicated-looking equations. You just need to roughly understand diagrams of connections of individually simple things like inflow, outflow, stock, and feedback, while other diagrams show the development of the example systems under different conditions. The text verbally explains why this happens, and basically you need to understand only as much of the detail as you’re interested in knowing. Yet the behaviour-over-time graphs are apparently generated by real mathematical modelling, and the appendix contains model equations for those interested. As someone who understands the importance of mathematics in such a context but to whom complex mathematics doesn’t come naturally, I thought this a very good way to popularly introduce models involving mathematics. I might emulate it myself in my future writings.

While the first part is necessary for the uninitiated, the other two parts of the book are where the real meat is. First, important concepts of complexity theory such as self-organisation are introduced quickly and effectively and within the context of the systems perspective. Next chapter 4 explains why systems can act in ways that are at odds with out overly simple assumptions and intuitions. Chapter 5 gets even more interesting in explaining various types of real-life problems in terms of system functioning, from the Tragedy of the Commons to addiction. What’s more, it explains in a general abstract sense how such traps can be avoided. More in this practical vein follows in the next chapters as the author lists and discusses numerous leverage points for changing a system and then how to adopt and apply a systems perspective in general.

Several things about this book impressed me. One is simply the clarity. Another is how it brings such disparate fields of inquiry and experience under a general framework. I’m already used to that in complexity studies, but this was still a particularly good example. A third is the amount of insight, and the sheer number of good insights packed naturally into such a small space. *Thinking in Systems* gives its own perspective on important observations in other books I’ve been impressed by, particularly *Antifragile* by Nassim Nicholas Taleb and *From Knowledge to Wisdom* by Nicholas Maxwell.

The final point that impressed me is the connection to practice. While I love brilliant theories that are like mirage castles built in the air, I would also like to be able to apply what I study to practice. There are so many problems in the world that require new tools to solve. This book isn’t about giving a concrete solution to every problem. That would be impossible simply because of the sheer indefinitely large number of problems that could be tackled as system problems. The models of system behaviour given here are very general and abstract by necessity. It’s more like learning a new way to think about the problems, and that’s in fact precisely what it is about. If more people even just got rid of the simpler but sometimes inappropriate ways of thinking that don’t work when dealing with complex systems, that alone would be helpful for solving their problems. Learning these new ways to think instead would be even better.

A lot of what happens in the world demands a different way of thinking than we’re used to, the skill of thinking in systems. And that’s why I think this book, which presents it so accessibly, is a must-read for basically everyone.

**Rating: 4.5/5**

*Thinking in Systems: A Primer.* Donella H. Meadows, edited by Diana Wright. Chelsea Green Publishing, 2008.