First Principles Thinking

First Principles Thinking

Core principle: Strip away assumptions, conventions, and analogies. Reduce to fundamental truths you know, then rebuild. Most thinking is by analogy — "we do it this way because that's how it's done." First principles asks: why is it done that way at all?

Core Process

Step 1: Identify the Current Belief

• What's the existing approach?
• What problem is it solving?
• What does everyone in this space assume?

Step 2: Challenge Every Assumption

For each element ask:

• "Is this actually true, or do we believe it because we've always believed it?"
• "Constraint of reality, or constraint of convention?"
• "What would have to be true for this assumption to be wrong?"

Distinguish:

• Physical constraints — laws of nature, math, physics — real
• Resource constraints — time, money, people — real but changeable
• Conventional constraints — "you can't do X" meaning "nobody has yet"
• Inherited assumptions — decisions made for past conditions

Step 3: Identify the Fundamental Truths

Stripped of convention:

• Core need being served?
• Irreducible requirements?
• What if designed from zero, knowing only what's physically true?

Step 4: Rebuild From the Ground Up

• Simplest approach that satisfies the real requirements?
• What if invented today, with today's capabilities?
• What constraints can be eliminated now that you're not inheriting them?

Output Format

Current Belief / Approach

• Existing design, strategy, or assumption
• Why it exists (historical/conventional)
• Problem it was meant to solve

Assumption Deconstruction

Fundamental Truths

• Core need
• Hard constraints (genuinely immovable)
• Validated facts (empirically confirmed)

Rebuilt Solution

• Solution without inherited assumptions
• What changes dramatically?
• What stays the same (and which fundamental truth supports it)?
• What's now possible that wasn't?

Assumption Risks

• If any single assumption proves wrong, what breaks?
• Which to validate before committing?

Thinking Triggers

• "What is this actually trying to accomplish at the most basic level?"
• "If we were building this today with no legacy, what would we do?"
• "Law of nature or law of habit?"
• "Who decided this was the right way, and what were their constraints?"
• "What would a brilliant outsider — who doesn't know our conventions — suggest?"
• "Are we solving the problem, or our version of the problem?"

Analogy vs. First Principles

Most thinking is analogy: "company X does it this way" / "industry standard is Y" / "always been done." Fast and usually adequate, but inherits the constraints and mistakes of the original. For genuinely novel solutions or step-change improvements, only first principles gets you there.

Example Applications

• "Should our agent pipeline be sequential?" → Why sequential? Ordering of dependencies, or convention from waterfall?
• "We need a dedicated QA team" → Necessary function, or historical artifact when testing was slow and manual?
• "Our API needs versioning" → Actual need is backward compatibility — minimum mechanism from scratch?
• "We need standups every day" → Need is coordination — all the ways to achieve it, unconstrained by "meeting" as a format?