The Model Is Not the Mind: External Cognitive Substrates and the Two Experiments That Show Why

Models are powerful reasoning engines, but they are poor places to locate persistent decisions, constraints, provenance, identity, and governance state. Those things need to survive session boundaries, model swaps, restarts, audits, and deployment environments where “the model usually follows the instruction” is not good enough.

PCS relocates durable cognitive authority into an external substrate. The model becomes a bounded reasoning engine operating over state it does not own.