[Book Review] The Great Mental Models
By Shane Parrish
Charlie Munger once said he firmly believed in the discipline of mastering the best of what other people already figured out. So much can happen in life, that life itself is far too short to experience it all yourself. Let alone digest it all, learn from it and try to shape your own train of thought. It’s impossible. At The Agile Mindset, we believe Charlie was right. We read, listen, watch, experience and let us be guided by the success and failure of others. Today, we’d like to share insights with you from a book by Shane Parrish, Founder of Farnam Street. He wrote ‘The Great Mental Models: General Thinking Concepts’. Let’s dive in.
On the cover of the book which has a beautiful finish -you know those older books with a cloth-like cover and nicely embossed letters- we see a wooden toolbox. Just like the one my grandpa had in his old shed in the garden. It is filled with all sorts of things: a map, a razor, a laboratory bottle and so on. When a plumber is called to your home to fix a broken shower, he doesn’t know what tools he will need upfront, so he brings a toolbox full. Each tool has a specific application. Through experience, the plumber knows when to use which tool.
In his book ‘The Great Mental Models: General Thinking Concepts’, Shane Parrish describes 9 mental models that are useful to have in our own mental toolbox, our brain:
The map is not our territory
Circle of competence
First Principles Thinking
Thought Experiment
Second-Order Thinking
Probabilistic Thinking
Inversion
Occam’s Razor
Hanlon’s Razor
These mental models help us to analyse complex situations, to influence our own thinking, to shape us into who we are. And the great thing is that many people before us have written many of them down. Shane Parrish’s goal is to share as much of this knowledge as possible Each of them is clearly explained and he gives us examples of how the model could be applied, as well as some history on how it came to be.
“For a man with only a hammer, every problem looks like a nail.” Abraham Maslow
And sometimes it’s hard to find the origin. One of my favourite mental models he describes is Hanlon’s Razor. As Parish describes: ‘Hard to trace in its origin, Hanlon’s razor states that we should not attribute to malice that which is more easily explained by stupidity.’
It is almost poetry, but everyone knows the feeling of shouting behind your steering wheel to the person who cut you off right in front of you. The odds that they did it on purpose are so small, that the much more simple explanation is that the person just did not see you. It was a mistake. Sometimes these mental models are not the big philosophical topics, but can mean a big difference if you use them thoughtfully.
For people using the Zettelkasten method this book is filled with good references to other books, people, quotes, resources and much more. I often had to pause reading the book, to update my own digital brain. For those who are interested: we use Obsidian as our digital Zettelkast1, more on that in a future post.
The book is riddled with small bits of knowledge, but beware, those looking for a complete guide on how to use these models practically or full comprehensive guidelines might be underwhelmed. The book will stimulate your brain and give you a good foundation for further thought: cross reference these models with what you already know. Charlie Munger, him again, tells us that we need to hang experiences onto a big latticework of mental models in our heads. The power of combined knowledge and experience is not to be underestimated.
One mental model which is briefly quoted in the book: ‘For a man with only a hammer, every problem looks like a nail.’ This is also known as Maslow’s Hammer. A mental model named after Abraham Maslow. To get where they want to go people tend to use what they already know, even if it is not the best way to get there. By expanding your mental latticework of mental models, you can improve your thinking and avoid being the man or woman with only a hammer. Combined with eg. the Cynefin framework we’ve talked about in the previous posts, these mental models will help and support you in making the right decision at the right time.
The Great Mental Models: General Thinking Concepts is a great start in your journey to do exactly that!
Zettelkasten is the German word for ‘card file’.