Ground truths

Skill chrisdavidson/first-principles-skill/first-principles/skills/ground-truths

Claude Code plugin for systematic first-principles thinking — a 5-phase methodology (identify essence, challenge assumptions, establish ground truths, reason upward, validate) plus 13 companion skills. Installable via the Claude Code plugin marketplace; every conclusion traces back to a verified ground truth, not to analogy or convention.

Install

npx -y skills add chrisdavidson/first-principles-skill --skill ground-truths

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Slash-only Phase 3 stub — compile GT-ID-anchored verified facts for derivation chains.

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SKILL.md

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Focused Ground Truths Mode

You are running in focused-ground-truths mode. Execute only the procedure below and produce only its canonical output sections — do not run the full 5-phase first-principles analysis. Skip Step 0 technique selection; the user has already chosen this technique by invoking the slash command directly.

When to reach for this

Use this phase once the Classified Assumptions Table from Phase 2 is finalized. Assumptions classified as physical law are ready to be promoted to ground truths; others have been challenged and their verdicts recorded. Reasoning from assumptions treats contested claims as solid foundations. Ground truths — facts that survive the scrutiny applied in Phase 2 — are the only reliable anchors for derivation chains. Without an explicit list of verified ground truths, the analysis cannot distinguish a conclusion built on solid facts from one built on well-packaged conjecture.

Procedure

Compile the verified ground truths from the Phase 2 analysis. A ground truth must pass the irreducibility test: it is a fact, not a belief; it can be traced to a verifiable source; and it cannot be simplified further without losing its essential claim. Assign each ground truth a stable identifier (GT-1, GT-2, etc.) that does not change for the life of the analysis. Unverified facts that must be used may be included but get the GT-N? suffix and inherit the confidence caveat rules from D-07. Do not include assumptions that failed Phase 2 scrutiny — discarded assumptions belong in the Abandoned Reasoning section of the output document (section 5), not here.

Named artifact: Ground Truths list — a numbered list of verified facts with stable GT-IDs and source citations. Unverified entries are marked with the ? suffix.

Exit criterion: All ground truths have stable IDs, source citations or explicit unverified flags, and have passed the irreducibility test. No assumption that was discarded in Phase 2 appears in this list. The list is complete enough that Phase 4 can reason upward without needing to return to Phase 2 for new facts.

If a fuller analysis is needed afterward, invoke the main first-principles agent with this output as Known ground truths.