<p>This paper examines the dissolution of the boundary between human and artificial cognition into a single, mutually conditioning epistemic ecosystem. As AI systems train on human-generated knowledge and as humans increasingly reason through AI-mediated outputs the two cognitive streams are no longer separable. What emerges is not collaboration but a closed loop in which independent judgment, at either end, becomes structurally difficult to sustain.</p> <p>The paper traces two parallel epistemic crises: the amplification of human cognitive vulnerability to structured authority, and the progressive weakening of AI grounding as training data becomes increasingly AI-influenced. It maps the resulting trust dynamics, identifies the circularity problem that limits genuine external grounding, and establishes why exit from the ecosystem is not a viable governance strategy.</p> <p>Two practical responses are proposed. The Epistemically Independent Human (EIH) addresses the failure mode of symbolic oversight by identifying the dispositional and institutional conditions under which genuine human judgment can be preserved at critical decision points. The scenario-specific AI framework addresses the deployment philosophy that generates diffuse, ungovernable failure modes, arguing for narrow, honestly calibrated, independently validated systems whose failure modes are known and bounded. Both proposals are implementable within current operational reality. The paper concludes that the window for structural intervention in AI governance is open but narrowing, and that the cost of adequate governance rises with every year it is deferred.</p>