first-principleslisted

# First Principles ## Overview Most reasoning is reasoning by analogy: *X resembles Y, so do what Y does.* It is fast, usually right, and silently inherits every assumption baked into Y — including the wrong and expensive ones. First-principles reasoning strips a problem to statements that **cannot be reduced any further** — physical law, mathematical identity, a definition, or a cited empirical fact — and rebuilds the answer using only those. This is one of three composable motions in the deciqAI collection: **first-principles** decomposes *downward* to bedrock; [occams-razor](../occams-razor/SKILL.md) chooses *sideways* among competing accounts you could build on top of bedrock; [second-order-thinking](../second-order-thinking/SKILL.md) traces *forward* through time and consequence. Compose: reduce to find the foundations (here), pick the simplest hypothesis that fits the evidence (occams), then trace where that pick actually leads (second-order). ## When to Use **Use when:** decision is justified mainly by "that's how it's done" or authority; conventional answer is expensive/hard to reverse (pricing, architecture, business model); structuring a knowledge artifact from irreducible elements; user says "from first principles," "from scratch," "why do we believe this," "tear this apart." **Skip when:** routine reversible decision where convention is cheap (which linter) — tearing down is theater; facts aren't gathered yet; user asked for speed and the conventional answer