Definition
A domain of applicability is the range of conditions where a model, theory, or vocabulary gives reliable explanations and predictions.
Why It Matters
Intellectual catastrophes often happen not because a theory is “wrong,” but because it is used outside its safe zone. Understanding the Domain of Applicability matters because it prevents “category errors”—like using the laws of physics to judge a poem, or using the logic of a small family to run a global economy. Identifying these boundaries is the only way to build a “latticework of mental models” that actually works, ensuring you don’t crash your system by trying to fly a car like a plane.
Core Concepts
- A theory can be excellent locally without being final globally.
- Failures outside a domain do not invalidate success inside it.
- Confusion often comes from applying a vocabulary at the wrong scale.