No. 328 · Fixing problems · Mathematics
Inversion
To find the way to success, first work out what would guarantee failure, then avoid it.
In the Almanac
“Jacobi turns it round”, 1829 · “Atlassian”, 2010s
Both stories in full, three ways to use it and where it misleads.
Get the AlmanacQuestions
What is Inversion?
Inversion is a problem-solving technique that flips the question. Instead of asking how to succeed, you ask what would guarantee failure, then avoid it. The mathematician Carl Jacobi advised that one must always invert, and Atlassian's pre-mortem asks teams to imagine a project has already failed.
How do you use Inversion?
To use it, run a pre-mortem before big launches, list the habits that would ruin your finances, and ask what would make loved ones feel ignored. Then avoid those things. Use it alongside regular planning.
When does Inversion matter?
Inversion is one of the 40 mental models for fixing problems, the situations where you ask: Why does this keep going wrong, and how do I fix it for good? Within that, it belongs to “Finding the real cause”, alongside Black Box, First Principles Thinking and Lateral Thinking.
What is an example of Inversion?
Two stories show it at work: Jacobi turns it round (1829) and Atlassian (2010s). Both are told in full in The Mental Models Daily Almanac, which has two stories for each of its 365 models.
Which mental models are related to Inversion?
Murphy’s Law, Margin of Safety and Devil’s Advocate Position. Inversion itself comes from mathematics.