First-Principles Thinking, Without the Buzzword

First-principles thinking has become a slogan, which is a shame, because the underlying practice is genuinely powerful. It means breaking a problem down to the things you know are true and reasoning back up from there — instead of copying the shape of existing solutions.

Assumptions are borrowed conclusions

Most of what we 'know' about how to build something is inherited. That is usually efficient — until the inherited assumption is the very thing standing between you and a better design.

Good engineering is mostly the courage to ask why a constraint exists, and the patience to check.

— Tomás Vega

The method, concretely

• Name the goal in terms of outcomes, not existing solutions.
• List the constraints, then separate physics from convention.
• Rebuild the simplest thing that could possibly work.

The output is not always a radical redesign. Often it is simply confidence — you now understand why the conventional answer is the right one.