First Principles Thinking

Definitions

Breaking down problems to their fundamental truths and reasoning up from there, rather than reasoning by analogy. Popularized in tech by Elon Musk. Powerful when genuine, insufferable when used to justify ignoring domain expertise.
In plain English: Solving problems by starting from basic truths rather than following conventional wisdom — questioning every assumption to find better solutions.
The danger of first-principles thinking is reinventing wheels. Existing solutions exist for good reasons; dismissing them as 'conventional thinking' can waste years solving already-solved problems. The skill is knowing when to apply first principles and when to leverage existing knowledge.
Example: 'He first-principled the database layer and built a custom storage engine. Six months later, he'd reinvented PostgreSQL, poorly. Sometimes conventional wisdom is just wisdom.'
Source: cautionary perspective