First principles

First principles are the most basic truths or assumptions underlying a subject — ideas you cannot derive from simpler ideas within that system.

First-principles thinking means solving a problem by:

1. Breaking it down into facts that are justifiable.

2. Separating those facts from convention, analogy, and “how it’s normally done.”

3. Building a solution upward from the fundamentals.

Reason from what must be true, not from what has usually been done.