The Great Mental Models

It’s the kind of book you don’t consume; you install. The Great Mental Models gives you a richer toolkit for thinking. Think of it as adding software modules to your brain. I’ve read many books that promise to “change how you think.” This one actually delivers.

“You can’t make good decisions without good thinking. You can’t think well without the right models.”

What Parrish and Beaubien offer here is not a list of hacks. It’s a well-curated starting set of frameworks — a kind of mental operating system. Inversion, second-order thinking, probabilistic reasoning, first principles — if you’re in business, tech, policy, or just trying to avoid your own blind spots, these are not optional skills. They're required literacy.

Personal Takeaways:
Inversion: Useful when stakes are high and mistakes are expensive. When I ask “How could this go horribly wrong?” I suddenly see all the weak spots I missed when I was optimistic.
Circle of Competence: A gentle but firm reminder that confidence without clarity is just noise. I’ve since started labeling areas in my life as “proven,” “developing,” or “unknown.” Helps me avoid unforced errors.
First Principles: I find this most useful when others are copy-pasting solutions. It slows me down — but in a good way.

Bottom Line:
Reading this reminded me of what Charlie Munger once said: “Developing the habit of mastering the multiple models which underlie reality is the best thing you can do.” This book gets you started. But remember — knowing the models isn’t enough. The power is in applying them… repeatedly… until they’re second nature.