Mental Models for Better Decisions

Mental models are frameworks for thinking. They help you see problems from different angles and make better decisions by giving you a structured way to approach complexity.

Here are a few I keep coming back to.

First Principles Thinking

Break a problem down to its fundamental truths, then reason up from there.

Instead of asking “how do others solve this?”, ask “what do I actually know to be true?” and build from there.

When to use it: When you’re stuck, when conventional wisdom isn’t working, when you need to innovate.

Inversion

Instead of asking “how do I achieve X?”, ask “what would guarantee failure?” then avoid those things.

Charlie Munger’s favorite: “Tell me where I’m going to die, and I’ll never go there.”

When to use it: When planning, when risk assessment matters, when you’re not sure what success looks like.

Second-Order Thinking

First-order thinking: “If I do X, Y will happen.” Second-order thinking: “If I do X, Y will happen, which means Z will happen, which means…”

Most people stop at first-order. The real consequences are often in the second or third order.

When to use it: When decisions have long-term consequences, when you’re dealing with complex systems.

Hanlon’s Razor

“Never attribute to malice that which can be adequately explained by stupidity (or negligence).”

In practice: assume good intent until proven otherwise. Most problems are coordination failures, not character flaws.

When to use it: When someone screws up, when you’re frustrated with others, when assigning blame.

Map Is Not the Territory

Your mental model of something is not the thing itself. Maps are useful but always incomplete.

The map is not the territory. The menu is not the meal.

When to use it: When you’re confident about something, when your model isn’t matching reality, when planning.

What I’m Still Figuring Out

• How to know which model to apply when
• When models conflict, how to decide
• Whether thinking in models is itself a trap

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These are my notes, not a comprehensive guide. For deeper reading, check out “Poor Charlie’s Almanack” or Farnam Street’s mental models series.