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Updated Mar 15, 2026

Chapter 4: Reasoning From First Principles

AI reasons by pattern. It tells you what has worked before. First principles reasoning tells you what will work when nothing has been tried before.

Most advice -- from humans and AI alike -- is reasoning by analogy: "this worked for Company X, so it will work for you." First principles reasoning strips a problem to its base truths and rebuilds from there. This is the skill that produces original solutions instead of borrowed ones.

Teaching Aid

Core Skill

First Principles Reasoning -- the ability to identify base constraints, separate them from assumptions, and derive solutions through logical chains rather than borrowed patterns.

What You Will Learn

  • How to derive a contrarian argument from base constraints without AI
  • How to solve a novel problem with no established solution using first principles
  • How to uncover hidden assumptions through an Assumption Autopsy
  • How to rebuild a solution when foundational constraints change
  • The difference between reasoning from principles and reasoning from examples

Exercises

ExerciseWhat You DoLayers Used
1. Defend the Opposite (No AI)Write a 500-word contrarian argument without AI, identifying failure conditionsLayer 1
2. First Principles vs. AISolve a novel problem from constraints alone, then compare against AI's approachLayer 1, Layer 5
3. Assumption AutopsyUncover hidden assumptions by merging your list with AI-identified assumptionsLayer 2, Layer 4
4. Rebuild Under New ConstraintsRebuild your solution when a constraint changes, auditing which principles surviveLayer 4, Layer 6

Chapter Deliverable

A First Principles Portfolio containing your contrarian argument (written without AI), First Principles Worksheet with AI comparison, merged assumption map, rebuilt solution with principle audit, and all AI feedback with reflections.

What You Need

  • A web browser with access to claude.ai and chatgpt.com
  • 45 minutes of uninterrupted time without internet for Exercise 2
  • No other tools or references -- this chapter tests what you can derive independently