Let me ask you something: When Elon Musk looked at buying rockets in 2002, everyone told him the price was the price. Rockets cost hundreds of millions — that's just how it is. Instead of accepting that, he asked one question: "What is a rocket made of?"
He broke it down. Aerospace-grade aluminum alloys. Titanium. Copper. Carbon fiber. Then he checked commodity prices. The raw materials? About 2% of a rocket's sticker price. The other 98% was just convention, inefficiency, and "we've always done it this way."
Now ask yourself: What if you applied that same lens to your money?
Most people build wealth the same way they'd build a rocket by copying NASA's old blueprints. They invest in what their coworkers invest in. They budget like their parents did. They chase the same side hustles they saw on TikTok. That's reasoning by analogy — and it's the enemy of real financial freedom.
Let's rebuild wealth from scratch. First principles style.
The idea isn't new. Aristotle called it archai — "the first basis from which a thing is known." Twenty-three centuries later, Elon Musk describes it as "a physics way of looking at the world: boil things down to the most fundamental truths and say, 'What are we sure is true?' — then reason up from there."
Farnam Street uses a brilliant metaphor: imagine someone hands you a Lego house. Most people just move a few blocks around — a slightly better house, but still a house. First principles thinking means breaking the house into individual pieces, at which point you realize you could build a castle. Or a spaceship. Or anything.
Two practical techniques to get there:
Here's the kicker Farnam Street drops: "Everything that is not a law of nature is just a shared belief. Money is a shared belief. So is a border. So is Bitcoin. So is love."
If money is a shared belief, shouldn't we understand what we're actually believing in?
This is where things get wild. Aristotle already figured out what most of us still get wrong about money.
He broke exchange into four stages:
His point wasn't that profit is evil. It was that money without a purpose is meaningless. As he famously wrote: "Being wealthy consists in using things rather than in possessing them; for it is the activity and use of such things that makes up wealth."
Read that again. Wealth isn't your net worth number. It's not your account balance. It's what your money enables you to do.
If you have $5 million but never use it — no travel, no time freedom, no meaningful experiences — Aristotle would say you're not actually wealthy. You just have a large number attached to your name.
This is the first principle that changes everything: money is a tool for living, not a scorecard for winning.
So if we strip money down to its function — what does it actually do? Willem de Beijer's first-principles framework nails it. Money serves exactly three purposes:
Without a buffer, you'd have to spend your entire paycheck the day it lands and somehow predict every expense for the next month. The buffer smooths the gap between income and spending. It should hover around one month's expenses — nearly empty right before payday, full right after.
Life throws curveballs. Car breaks down. Medical bill appears. Three to six months of expenses in a savings account means you never have to sell investments at a bad time — or worse, go into debt — when the unexpected hits. This is your number one priority. Always.
Once your buffer and safety net are solid, every extra dollar goes here. Stocks. ETFs. Real estate. A side business. Anything where $1 today becomes $2 tomorrow, then $4, then $8.
As de Beijer puts it: "Building out your money factory over time gives you freedom. It makes you less reliant on your paycheck, and therefore allows you to start working less or retire earlier."
The priority order is non-negotiable: Safety Net → Buffer → Factory. Skip the safety net to chase returns and one emergency wipes you out. This is first principles, not gambling.
Ready to apply this? Here's the five-step framework:
Write down everything you "know" about money. "I need a 9-to-5 forever." "Investing is for rich people." "I'll never afford a house." Now Socratic-question each one. Why do you think that? Who told you? What evidence exists? What if the opposite were true?
Forget what Instagram says wealth looks like. What do you actually want money to do? Buy time with your kids? Travel? Build things? Create? Answer honestly. This is your financial telos.
Before a single dollar goes into stocks, have 3-6 months of expenses in a boring savings account. This isn't optional. Musk wouldn't launch a rocket without a launch escape system. Don't launch your wealth journey without one either.
Index funds. Dividend stocks. Real estate. A business. The vehicle matters less than the principle: money must work. Elon Musk's investing approach is instructive here — buy what you believe in, ignore market timing, hold long-term. Forbes noted in 2026: "The real edge comes from building portfolios that don't require precision to succeed."
Short-term thinking is reasoning by analogy — everyone's doing it, so you should too. First principles reveals that compound growth is the only free lunch in finance. Time in the market beats timing the market. Every. Single. Time.
First principles thinking is harder. It takes more mental energy than copying someone else's financial life. But the payoff is the difference between building a slightly better Lego house and building something nobody's seen before.
Aristotle figured this out in ancient Athens. Musk proved it with rockets and electric cars. Now it's your turn.
Stop asking "What are other people doing with their money?" and start asking "What is money actually for — in my life, on my terms?"
The answer to that question is your first principle. Everything else is just construction.
Your wealth. Your axioms. Your freedom.
