Invert, always invert - Carl Jacobi and Charlie Munger

Today something different not a business analysis but a mental model which is underused by many people in daily decissions not just in evaluating businesses.

Yesterday I read some section of Charlies Almanack again and thought that others might beneftit from this too and like it.

Carl Gustav Jacobi was a 19th-century German mathematician, would often say “Invert, always invert” (“man muss immer umkehren”). He meant that if you can’t solve a problem directly, try flipping it around: instead of asking “How can I succeed?”, ask “How can I avoid failure—and then avoid that path.”

Charlie Munger adopted this maxim into the investment and business world. For him, inversion is a mental model: by looking at problems backward, you strip away illusions and spot hidden risks and biases. If you want to be rich, study how people go broke. If you want a great business, ask what would destroy it, then check if management is guarding against that and study failing businesses from history.

Here is my personal twist with additions from other valuable people:

Risk framing instead of return chasing
Investors are often dazzled by growth stories. Inversion forces you to ask: what can permanently impair capital here? Debt, bad management incentives, technological obsolescence—these emerge more clearly when you think backwards.
Moat analysis through failure modes
Instead of asking “what makes this company strong?” invert: what could make it lose pricing power, customer stickiness, or cost advantages? This gets you to the essence of durability faster than hype-filled strategy decks.
Management evaluation by negative filters
Munger often said it’s easier to spot bad behavior than great genius. So, ask: does management overpay for acquisitions, dilute shareholders, manipulate accounting? If yes, you don’t need to know much else—you can move on.
Portfolio construction
Invert the question “How do I pick winners?” into “How do I avoid disasters?” That’s essentially Benjamin Graham’s defensive investor mindset. By eliminating obvious losers, you tilt odds massively in your favor.
Decision hygiene
Kahneman and Sibony (taken from the Book Noise) describe how judgments scatter. Inversion disciplines decision-making by pre-mortems: imagine your decision failed spectacularly—why? That surfaces blind spots before committing
Learning from history
Buffett likes to invert the market euphoria: instead of asking “Why buy tech stocks in 1999?”, ask “What are the reasons these stocks could collapse?” In 2008, the inversion was, “How can leverage destroy firms?” That clarity led Berkshire to deploy capital while others froze.

In practical business analysis, you could apply Jacobi + Munger like this:

Normal: “Will this company grow 15% annually?”
Inverted: “What would prevent this company from compounding? Regulation? A customer concentration risk? A product that can be replaced?”

By cataloging failure modes, you also clarify what has to not happen for success to occur. That builds your margin of safety mindset (Klarman echoes this: avoiding what others do wrong nearly ensures success.

So: “Invert, always invert” isn’t just a clever quote. It’s a Swiss army knife for analysis: it forces clarity, cuts through bias, and highlights the asymmetry between avoiding ruin and seeking gain.

Would you apply this framework in your own investing process?

Let me know if you find that intersting or helpful for improving and give me feedback if you like such posts in the future!