Originally posted on Medium.

Inversion is a cheat code for life. You can use inversion in finance, relationships, health, product development and so much more. Charlie Munger and many other world leaders use it to look brilliant by avoiding stupidity.

It is not enough to think about difficult problems one way. You need to think about them forwards and backward. — Charlie Munger

Inversion is the process of addressing problems backwards. Inversion helps you uncover your hidden beliefs about problems and allows you to avoid what you ultimately don’t want. It’s much easier to avoid what you don’t want than to get what you do want.

Forward: How do I get X?
Backwards: How do I not get X?


Premeditatio malorum — Stoics (AD 63–65) Stoic philosophers practiced the premeditatio malorum or premeditation of evils to envision the worst things that could happen in every situation.

Man muss immer umkehren — Carl Jacobi (1820) German mathematicianCarl Jacobi expressed that hard problems can be clarified by inverting them with his maxim ‘Invert, always invert’ (‘man muss immer umkehren’). Bershire Hathaway partner, Charlie Munger, has popularized Jacobi’s maxim over the past 20 years.

Prospective hindsight (1989) Deborah J. Mitchell, of the Wharton School; Jay Russo, of Cornell; and Nancy Pennington, of the University of Colorado, discovered that event imagination increases the ability to identify reasons for potential outcomes.

Premortem — Gary Klein (2004) Psychologist and best selling author, Gary Klein, offers a premortem guide to prospective hindsight in his book The Power of Intuition and HBR article on performing a project premortem.

Fear-setting — Tim Ferris (2017) Tim Ferris gives premeditatio malorum a more accessible name and guide in his 2017 TED talk. (1. Identify fears → 2. Benefits of risks → 3. Loss of inaction)

How to Use Inversion

Here’s a 3-step guide for using inversion and several examples on how the mental model can be applied to different situations.

  1. Define the problem you’re trying to solve.

  2. Invert the problem to clarify what you don’t want to happen.

  3. Avoid what you don’t want to happen.

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