Management & Thinking
ProFirst Principles Thinking
第一原理思考 · Source: Aristotle / Elon Musk
Breaking "we've always done it this way" inertia — rebuilding solutions from the ground up
Core Concept
Decompose the problem to its most fundamental truths — facts that cannot be broken down further — and rebuild the answer from there. Most people reason by analogy. First principles forces you out of that frame.
✓ When to use this
When "everyone does it this way" starts looking suspicious, or the cost/constraints of existing solutions feel unjustified. Break the problem to its irreducible facts and rebuild from there — often skipping industry blind spots.
✗ When not to use this
Skip when execution is severely time-constrained — decomposition is slow. Also unnecessary for market-validated, well-functioning standard practices; rederiving them wastes cognition.
Questions you will be asked
Using this framework, you will work through —
- 1.What problem or decision are you facing?
- 2.What are your current assumptions? (What do you take for granted?)
- 3.Examine each assumption: which are real constraints, and which are just convention?
- …and 3 more
Worked example
Expand to see what a filled-in run looks like
›
Worked example
Expand to see what a filled-in run looks like
Situation
經營一家小餐廳 5 年，每次想擴張就被「必須請更多廚師、租更大店面、開分店」的業界共識嚇退。但這個假設真的成立嗎？
1. What problem or decision are you facing?
想增加營收 50%，但不想被「請廚師 + 大店面」的傳統路徑綁住。
2. What are your current assumptions? (What do you take for granted?)
假設：擴張一定要實體店、廚師人力與營收成正比、客人會為新分店再來、品牌力來自店面而非產品本身。
3. Examine each assumption: which are real constraints, and which are just convention?
不可分割事實：客人付錢買的是「食物 + 體驗」；食物可以打包外帶或預製；體驗可以線上化（食譜、訂閱箱）；現有客人喜歡你的菜本身，不必依賴「新的店」。
4. If you start only from the irreducible facts, how would you redesign the solution?
從基礎重建：用既有廚房做高單價預製/冷凍商品線上販售，配合食譜訂閱+單次外送服務，營收可加 60% 而完全不需新店面。
5. How does your first-principles answer differ from your original plan?
反思：原本的擴張路徑是業界類比思考——「擴張 = 開分店」；第一原理是「擴張 = 觸及更多人吃到我的菜」。觸及方式可以非常不同。
6. Which direction will you take? Why?
不開分店。先試 6 個月電商 + 訂閱模式，3 個月內驗證單位經濟模型；若可行，年底再決定是否擴實體。
Use it inside ChatGPT / Claude
Paste the prompt below and the AI will walk you through this framework, one question at a time.
你現在是引導使用者做「第一原理思考」的教練（Aristotle / Musk）。 依序問： 1) 你正在解決的問題或決策是什麼？ 2) 你目前的假設與既有解法是什麼？（業界共識、預設選項） 3) 把這些假設拆到「不能再分割的事實」——什麼是物理、數學、或人性層面的真理？ 4) 從這些事實重新組裝答案——不參考類比、不依賴傳統。 5) 重新組裝後的方案，跟既有方案差在哪？這個差異有道理嗎？ 6) 你的修正版決策是什麼？ 特別追問：當使用者說「業界都這樣」、「沒人這樣做過」，逼他回到「事實層」回答。 互動規則： 1. 一次只問一題，等使用者回答後再進入下一題。 2. 使用者答完所有題目前，不要做總結或下結論。 3. 若答案太抽象、太籠統，請追問一次具體例子或數字後再繼續。 4. 全部答完後，輸出三段：(a) 摘要使用者的關鍵判斷；(b) 你看到的盲點或張力；(c) 一個具體下一步行動建議。 5. 不要替使用者做決定，只把判斷攤開讓他自己決定。
Related Frameworks
Management & Thinking
Second-Order Thinking
Complex decisions with cascading effects, strategic choices, any "obvious" decision — because first-order outcomes everyone sees are often already priced in
Management & Thinking
Inversion
Finding "how to guarantee failure" in order to reverse-engineer "how to guarantee success"
Investment & Finance
Munger's Decision Checklist
Running a major decision through Munger's multi-mental-model filter before committing
FAQ
How do I know I've actually reached first principles?
Test: are the things you're standing on "physical, mathematical, or independently verifiable facts" — or are they "industry convention," "common knowledge," "common sense"? When Musk attacked rocket cost, "rockets are expensive" wasn't a primitive — but "raw material costs (Al, Ti, Cu, carbon fiber) are 2% of rocket sticker price" was. You're at first principles when every premise traces to a quantifiable, verifiable source.
How is first principles different from 5 Whys?
Opposite directions. 5 Whys walks the causal chain upward — what caused this? What caused that? — to find the root cause. First principles walks the composition downward — what are this thing's irreducible parts? — to recompose. Fix what's broken with 5 Whys; design something new with first principles.
Do everyday decisions actually warrant first principles?
No — most daily decisions are fine on analogical reasoning ("how others do it") because consensus is usually 80% right. First principles earns its energy cost when: (1) you're stuck and every "reasonable" option feels wrong; (2) the decision will shape your life for 5+ years; (3) you suspect "everyone does it this way" is itself wrong. Outside those, analogy is cheaper and good enough.
Related studies