Mental model · Reasoning
First principles
First principles: Reasoning up from what must be true, rather than across from how it is currently done. Rebuild using only the laws.
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Reasoning up from what must be true, rather than across from how it is currently done.
Try it now
Take something you do a certain way. List every part of it, and mark each as a law of the situation or a convention someone chose.
What to do with the answer
Rebuild using only the laws. Then compare honestly with the conventional version — sometimes the convention wins, and knowing why is the gain.
Where it misleads
It is slow and expensive, and conventions often encode reasons nobody wrote down. Use it where the standard answer keeps failing, not everywhere.
The module it belongs to
- Problem Solving — Break complex problems into manageable parts
The book behind it
- Think like a rocket scientist — Its big ideas, in our own words.