First-principles thinking is overrated

Reasoning from first principles every time is exhausting and slow.

You don't have to derive everything from scratch. You're not Aristotle. You're trying to ship a thing.

First-principles thinking is useful when:

Tradition has clearly failed and you need a new approach.

The cost of being wrong is low and you can iterate quickly.

You're entering a domain where the inherited assumptions look broken.

It is not useful when:

The thing has been working for centuries and you want to try a new way for novelty's sake.

The cost of being wrong is high and you don't have the skill to evaluate the consequences.

You don't yet understand why the existing convention exists.

Most "first principles" reasoning in operating contexts is actually "I haven't bothered to learn why this convention exists, so I'll reason from scratch and discover, slowly, what previous people learned." That's not first-principles. That's reinvention with extra steps.

Three reframes:

Before you discard a convention, learn why it exists. Most conventions exist because the alternatives failed. Reading the history is faster than recreating the failures.

First-principles reasoning works best on top of competence, not as a substitute for it. The expert reasoning from first principles produces insight. The novice produces confusion.

Save first-principles thinking for the questions where the inherited answer is clearly wrong. Use tradition for everything else.

Most of operating is correctly applying the existing playbook. A small percentage is rewriting it. Don't confuse which mode you're in.

The first-principles brand is glamorous. Most of the work is not.