The First-Principles Toolkit
Mental models for thinking from scratch
When the playbook stops working, you don't need a better playbook. You need the moves underneath it. These are the six that get used most often by people who reset entire industries.
- 01Mental Models · Reasoning
First Principles
Strip the problem to irreducible truths and rebuild.
Break a problem down to irreducible truths and rebuild from there.
Open the full definition →Try it · 30 secondsLive · Catch first principlesYou're asked to cut battery cost. Pick the reasoning style.
- 02Mental Models · Reasoning
Inversion
Solve forward by asking how to fail.
Solve forward by asking how to fail.
Open the full definition →Try it · 30 secondsLive · Catch inversionYou're trying to build a 10x team. Pick the more useful question.
- 03Mental Models · Reasoning
Occam's Razor
Prefer the simplest explanation that fits the evidence.
Prefer the simplest explanation consistent with the evidence.
Open the full definition →Try it · 30 secondsLive example · Apply Occam's RazorUse the model. Pick the move.
Prefer the simplest explanation consistent with the evidence. You've just seen this: Sales are down because demand is down. Which lever does the model recommend?
● LivePick a lever. There are no neutral ones — every incentive funds a behavior somewhere.
- 04Mental Models · Decision
Second-Order Thinking
Ask 'and then what?' — twice.
Ask 'and then what?' — twice.
Open the full definition →Try it · 30 secondsLive example · Apply Second-Order ThinkingUse the model. Pick the move.
Ask 'and then what?' — twice. You've just seen this: Quarterly bonuses make this quarter great and erode the next five. Which lever does the model recommend?
● LivePick a lever. There are no neutral ones — every incentive funds a behavior somewhere.
- 05Mental Models · Reasoning
Map vs. Territory
The deck is not the strategy.
Models are simplifications — never the thing itself.
Open the full definition →Try it · 30 secondsLive example · Apply Map vs. TerritoryUse the model. Pick the move.
Models are simplifications — never the thing itself. You've just seen this: GPS is useful until you drive into a river. Which lever does the model recommend?
● LivePick a lever. There are no neutral ones — every incentive funds a behavior somewhere.
- 06Mental Models · Reasoning
Circle of Competence
Know the perimeter of what you actually know.
Know the perimeter of what you actually know.
Open the full definition →Try it · 30 secondsLive · Catch circle of competenceYou're an excellent operator in B2B SaaS. A friend pitches you a biotech investment. The deck is compelling.
Memorize the names. Internalize the moves. Use them in real meetings, not just essays.
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