Monday morning, January 19th. You're in a product meeting. Someone proposes using an established framework for the authentication system. Immediately, someone else says: "Wait, let's think about this from first principles. What are we actually trying to achieve here?" Three hours later, you've debated the nature of identity, questioned whether passwords are even necessary, and produced a Miro board that looks like a conspiracy theorist's basement. You've also made zero progress. Meanwhile, your competitor shipped their feature using OAuth2 in twenty minutes. Here's the truth nobody wants to hear: first principles thinking has become intellectual theater—a way to signal depth while avoiding the hard work of learning what's already known.

The Thesis

First principles thinking is powerful when used sparingly by experts who understand what they're deconstructing. In the hands of most people, it's an excuse to ignore accumulated knowledge, reinvent solved problems poorly, and feel intellectually superior while making slower progress.

The tech world has developed a fetish for "reasoning from first principles." Elon Musk does it. Physics people do it. Therefore, we should all do it for everything. Except most people don't understand when it's useful versus when it's just expensive intellectual posturing.

The result: a generation of people who can't build on existing solutions because they're too busy reinventing foundations, and who mistake "thinking really hard about basic questions" for actual innovation.

What First Principles Actually Is

Real first principles thinking:

  • Break down a problem to its fundamental truths
  • Discard assumptions and conventional wisdom
  • Rebuild solutions from those foundations
  • Used when existing solutions are fundamentally inadequate
  • Requires deep domain expertise to know what's actually fundamental
  • Reserved for genuinely novel problems or broken paradigms

Examples of appropriate use:

  • SpaceX questioning why rockets cost so much (identifying material costs vs. organizational costs)
  • Rethinking electric vehicles from battery chemistry up
  • Challenging core assumptions in a stagnant industry
  • When the existing solutions are provably inadequate for your constraints

When Elon Musk uses it: He's not rediscovering physics. He's questioning economic and organizational assumptions about rocket manufacturing because he deeply understands the domain and can identify which "conventional wisdom" is actually just calcified inefficiency.

What First Principles Has Become

The current fetish:

  • Question literally everything about every problem
  • Refuse to use existing solutions without "understanding them from scratch"
  • Rebuild from scratch because "we're thinking from first principles"
  • Applied to every problem regardless of whether it needs it
  • Used by people who lack domain expertise to evaluate what's fundamental
  • Confused with depth of thought

What actually happens:

  • Junior developer: "Before we use React, let's think from first principles about what a UI framework should do"
  • Result: 6 months later, you have a worse version of React from 2015
  • Actual first principles conclusion should have been: "UI frameworks solve X, Y, Z problems, React does this well, use React"

The pattern:

  1. Encounter a problem
  2. Declare you're "thinking from first principles"
  3. Question everything, including things you don't understand
  4. Produce a "novel" solution that ignores decades of accumulated knowledge
  5. Discover your solution has the same problems as the ones everyone moved past in 1997
  6. Either admit defeat or double down on "we're doing something different"

Why People Love It

It feels like depth:

Questioning basic assumptions feels profound. "What even is authentication?" sounds deeper than "Let's use OAuth2."

But depth isn't measured by how far back you go—it's measured by how well you understand the entire landscape, including why things evolved the way they did.

It signals intelligence:

Saying "I'm thinking from first principles" is intellectual peacocking. It says: "I'm not one of those sheep who just uses existing solutions. I think."

It's a way to position yourself as a deep thinker while avoiding the unglamorous work of understanding why existing solutions exist.

It gives permission to ignore expertise:

If you're reasoning from first principles, you don't need to read the literature. You don't need to understand the history. You don't need to learn from people who spent decades in the field.

You can just think really hard and trust your reasoning over accumulated wisdom.

It delays decisions:

Can't decide which database to use? "Let's think from first principles about what we're storing and why." Congratulations, you've turned a 2-hour decision into a 2-week philosophy seminar.

The first principles framing makes the delay feel intellectually rigorous instead of like decision paralysis.

What's Actually Happening

You're reinventing solved problems:

99% of problems you encounter are not novel. They've been solved. The solutions exist. Many of them are good.

"Thinking from first principles" in these cases means ignoring the solutions and their hard-earned lessons, then rediscovering the same solutions through trial and error.

That's not innovation. That's expensive historical reenactment.

You lack the expertise to do it well:

First principles thinking requires knowing what's actually fundamental versus what's contingent. That requires deep domain expertise.

A physicist can reason from first principles about physics because they know which principles are truly first. You can't reason from first principles about authentication systems if you don't deeply understand cryptography, user behavior, attack vectors, and the history of auth failures.

Without that expertise, your "first principles" are just your current assumptions with extra steps.

You're confusing rebuilding with understanding:

Real understanding often comes from studying why things are the way they are. Why did REST APIs emerge? What problems did they solve? What tradeoffs did they make?

That historical and theoretical understanding is deeper than "let me redesign APIs from scratch without knowing that history."

You're falling for the narrative:

The famous first principles success stories all involve domain experts questioning specific assumptions in areas they deeply understood. They weren't starting from zero knowledge.

You're copying the narrative without copying the expertise that made it work.

The Uncomfortable Reality

Most progress comes from learning deeply, not thinking freshly.

The people who make actual breakthroughs typically:

  • Spend years mastering existing knowledge
  • Deeply understand why current solutions exist
  • Identify specific inadequate assumptions
  • Question those specific things, not everything
  • Build on existing solutions, not from scratch

Meanwhile, the "first principles" crowd produces people who:

  • Are suspicious of all existing solutions
  • Spend months on problems with known solutions
  • Create brittle, poorly-understood systems
  • Repeat historical mistakes
  • Feel intellectually superior while making slower progress

The actual skill is knowing when to use it:

First principles thinking is a tool for specific situations:

  • When existing solutions are provably inadequate for your constraints
  • When you have deep enough domain expertise to identify what's fundamental
  • When the problem is genuinely novel or the paradigm is genuinely broken
  • When the cost of rethinking is justified by the inadequacy of existing approaches

For everything else—which is most things—the better approach is:

  • Learn existing solutions deeply
  • Understand their tradeoffs and reasoning
  • Identify specific inadequacies for your use case
  • Make targeted improvements, not wholesale reinvention

What To Do Instead

Learn the landscape first:

Before questioning everything, understand what exists and why. Read the papers. Study the history. Learn from people who've spent decades in the field.

That's not intellectual laziness—it's intellectual efficiency. You're building on accumulated knowledge instead of rediscovering it.

Question specific assumptions, not everything:

Real expertise is knowing which assumptions to question. Not "what is authentication?" but "why does the OAuth flow require this redirect step, and is there a better approach for our use case?"

Targeted questioning based on deep understanding beats wholesale reinvention based on surface-level thinking.

Recognize when the problem is solved:

Most problems you encounter have good-enough solutions. Using them isn't intellectual surrender—it's focusing your creative energy where it actually matters.

Save the first principles thinking for problems where existing solutions are genuinely inadequate, not just unfamiliar to you.

Value accumulated wisdom:

Existing solutions embody lessons from thousands of failures. The boring best practices exist because people tried the "clever" alternatives and they failed in production.

That accumulated wisdom isn't something to dismiss—it's something to leverage.

Build on, don't rebuild:

Real innovation usually looks like: "Here's the existing solution, here are its specific inadequacies for this new context, here's a targeted improvement."

Not: "I'm going to rethink everything from scratch and definitely won't encounter the same problems everyone before me hit."

Takeaways

First principles thinking is powerful when used correctly—by domain experts questioning specific inadequate assumptions in genuinely novel situations. But tech culture has turned it into intellectual theater: a way to signal depth while ignoring accumulated knowledge and reinventing solved problems poorly. Most people using it lack the domain expertise to identify what's truly fundamental versus what's contingent, leading to expensive rediscoveries of existing solutions complete with all their historical mistakes.

Most progress comes from learning deeply, not thinking freshly. Real breakthroughs come from people who mastered existing knowledge, deeply understood why current solutions exist, and then questioned specific inadequacies—not from people starting from scratch without that foundation. The "first principles" fetish produces developers who are suspicious of all existing solutions and spend months on problems with known answers.

The actual skill is knowing when to use it. Apply first principles thinking when existing solutions are provably inadequate for your constraints and you have deep enough domain expertise to identify what's fundamental. For everything else—most things—learn existing solutions deeply, understand their tradeoffs, and make targeted improvements rather than wholesale reinvention.

The path forward: Before declaring you'll "think from first principles," ask: Do I have deep enough domain expertise to know what's fundamental? Is the existing solution genuinely inadequate, or just unfamiliar? Is the problem novel enough to justify rebuilding from scratch? If you can't answer yes to all three, the better path is to learn the landscape, understand why things are the way they are, and build on accumulated wisdom. Save your creative energy for problems where existing solutions are genuinely inadequate—not for performative intellectual depth that produces slower progress and repeated mistakes. The goal is to make things better, not to feel clever.

Today's Sketch

January 19, 2026