First Principles Strip assumed constraints to independently supported primitives, then rebuild. Escape analogy when convention fails or looks artificially expensive. When to Use - A constraint is treated as fixed ("too expensive," "impossible," "always done this way") without independent support. - Convention or analogy has failed, stalled, or only yields weak incremental variants. - Greenfield design where industry defaults may smuggle false requirements. - Cost or feasibility claims rest on pricing, precedent, or authority rather than physics, math, or measured need. When NOT to Use - The c…