First Principles Thinking
Start from the basic facts of your problem, not from what competitors are doing — otherwise you inherit their constraints as if they were yours.
Why PMs should care
Most product arguments in a roadmap review are comparisons: 'Revolut does it this way', 'Stripe's docs look like that', 'our competitor just shipped X'. Comparing is cheap and usually close enough, but it breaks in regulated or genuinely new problems — because the comparison brings along constraints that don't apply to you, and hides ones that do.
First principles asks: what does the user actually need to do here? What does regulation, physics, or the user's real day actually require? What's the smallest set of steps you can't remove without breaking the job? Build the flow from there, and only compare with the competitor's version at the end.
The reward: every so often you'll find an entire step the industry has been doing for no reason, just because the first company to do it did it that way.
Example in product work
Roadmap review: 'Our KYC needs to take under three minutes because N26 and Revolut are both around four and Monzo claims two-fifty.' That's reasoning by analogy, and it sets a target that has nothing to do with your users.
First principles: the mandatory data fields are {name, DOB, address, tax ID, ID document, selfie match}. At 95th-percentile typing speed on mobile with good autofill, that's ~110 seconds.
Drop-off data shows the failure isn't time — it's the tax ID step in France specifically, where users don't know their number and need to leave the app to find it. The right project is 'help French users find their tax ID inside the flow', not 'shave 30 seconds off the whole thing'.
The analogy would never have produced that.
What to do when you see it
- Most product arguments are comparisons: 'Revolut does it this way'. That's cheap reasoning, and it breaks in new or regulated spaces.
- Ask what the user actually needs to do, what regulation actually requires, and what the minimum steps are — then rebuild from there.
- Compare your result against the competitor's version afterwards, not before.
- Every so often, first-principles thinking reveals a step the whole industry has been doing for no reason.
Sources & further reading
- First Principles — Farnam StreetShane Parrish's comprehensive treatment of reasoning from first principles, with examples from Aristotle to Musk.
- Elon Musk on First Principles — TEDMusk's own explanation of how he uses first-principles reasoning in product and engineering decisions.