"First principles thinking is the act of boiling a process down to the fundamental parts that you know are true and building up from there. Let's discuss how you can utilize first principles thinking in your life and work.

Defining First Principles Thinking

A first principle is a basic assumption that cannot be deduced any further. Over two thousand years ago, Aristotle defined a first principle as “the first basis from which a thing is known.”

First principles thinking is a fancy way of saying “think like a scientist.” Scientists don’t assume anything. They start with questions like, What are we absolutely sure is true? What has been proven?

In theory, first principles thinking requires you to dig deeper and deeper until you are left with only the foundational truths of a situation. Rene Descartes, the French philosopher and scientist, embraced this approach with a method now called Cartesian Doubt in which he would “systematically doubt everything he could possibly doubt until he was left with what he saw as purely indubitable truths.”

This is a good strategy for critical thinking. Although most of James' examples are physical I suggest the concept has a wider application, even into spiritual practice.

First Principles: Elon Musk on the Power of Thinking for Yourself — by James Clear

https://jamesclear.com/first-principles