---
name: first-principles-thinking
description: >
  Use this skill when the user asks for first-principles thinking or wants to
  reason from bedrock—stripping borrowed analogies and convention, surfacing
  fundamentals, then rebuilding the reasoning chain and implications. Use when
  they want to reason from scratch, challenge industry defaults, want physics-style
  business breakdowns, or sanity-check whether copying incumbents still makes
  sense, even if they never say first principles. Skip when they want a quick
  convention-following checklist with no rebuild of assumptions, or purely
  social coordination with no modeling ask.
license: MIT
metadata:
  author: ysskrishna
  version: "2026.5.17"
---

# First Principles Thinking

Question inherited baggage. Rebuild only from **bedrock** you can defend.

---

## When to Use

Use when analogies may mislead: new markets, hard tech, cost structure invention, personal strategy against social scripts. Less useful when best practice is truly optimal and context-free.

---

## Setup (run before starting)

In one short block:

1. **Reconstruction target** — belief, cost, design, or strategy to ground
2. **Default pass** — Surface → Question → Bedrock → Rebuild → Implications (state this line)

Up to 3 questions on immutable constraints (physics, law, budget); mark unknowns `[UNKNOWN]`.

---

## The Steps

### Surface

State the **conventional answer** or analogy people rely on. List **loaded words** or hidden comparisons ("like Uber for…").

### Question

For each major assumption: **Assumption:** … — **Why believed?** (authority, analogy, experience) — **What if false?**

### Bedrock

List **fundamental truths** that survive scrutiny — physics, logic identities, legal musts, documented preferences of real users, arithmetic. Label each `[FUNDAMENTAL]` vs `[STILL ASSUMPTION]`.

Aim for **at least 3** bedrock items; if fewer are honest, explain why.

### Rebuild

From **only** `[FUNDAMENTAL]` items, derive conclusions in numbered steps. No smuggled analogies; if you need a new premise, add it to **Bedrock** first with a tag.

### Implications

**So what** for decisions: what changes vs the conventional path? **Cost of being wrong** if a tagged assumption fails.

Add a short **vs convention** contrast (a few bullets or a two-column mini-summary) if it clarifies the decision.

---

## Execution Rules

1. **Rebuild** cannot cite "industry standard" as a premise unless translated into a fundamental (e.g. "buyers require SLA X because regulation Y").
2. If bedrock is too thin to rebuild, say **insufficient grounding** and list what evidence would fix it.
3. Avoid faux profundity; keep steps short and checkable.

---

## Checklist (verify before responding)

- [ ] Setup: reconstruction target + default pass
- [ ] Surface names convention or analogy explicitly
- [ ] Question step ties assumptions to why held
- [ ] Bedrock uses `[FUNDAMENTAL]` / `[STILL ASSUMPTION]`
- [ ] Rebuild chain only uses fundamentals
- [ ] Implications name what changes vs convention (and vs-contrast if helpful)