Identify the deepest assumption in each decision domain…

For each major domain where you make decisions, explicitly write down the single deepest assumption everything else depends on, then list 5-10 decisions that would change if that root were different to verify you've found an actual root.

When This Fires

During deep self-reflection about major life or career domains
When multiple decisions in the same domain keep producing unsatisfying results
During strategic reviews when questioning foundational premises
When you suspect a systematic error in a decision domain but can't identify the source

Common Failure Mode

Identifying a mid-level assumption as the root: "My deepest career assumption is that I should work at startups." But why startups? "Because I value autonomy." Why is autonomy the priority? "Because I believe the best work comes from self-directed people." That last statement is closer to the root — and changing it would cascade through career decisions, management style, collaboration preferences, and work environment design.

The Protocol

For each major decision domain: (1) Write: "The single deepest assumption underlying my decisions in [domain] is: [one sentence]." (2) Verify: list 5-10 specific decisions that would change if this assumption were different. (3) If fewer than 5 decisions would change → you haven't found the root. Ask "why do I believe this?" and go deeper. (4) If 5-10+ decisions would change → you've found a genuine root assumption. Now evaluate it: is this assumption well-supported? Has it been tested? When was it last examined? Root assumptions that cascade through many decisions deserve the most rigorous scrutiny.