The Separation Principle
Planning, state, memory, and evaluation should live outside the model. Models reason; systems remember, plan, and verify.
The Separation Principle formalizes System-Centric AI as an architectural requirement. When the model is responsible for planning (deciding what to do next), state management (remembering what's been done), memory (retaining knowledge across sessions), and evaluation (assessing its own work), each responsibility degrades the others. The model spends reasoning tokens on bookkeeping instead of on the actual task. Separating these concerns allows each layer to be optimized independently: the planning layer can be deterministic, the memory layer can be persistent, the evaluation layer can be rigorous, and the model can focus on what it's best at โ reasoning.