Cognitive Commons in the Age of Generative Intelligence: A Heterodox Appraisal of the Knowledge Erosion Hypothesis

The proposition that agentic artificial intelligence may precipitate a depletion of collective cognitive capital has circulated with unusual velocity in both scholarly and public discourse. The present paper offers a deliberately heterodox reading of the dynamic model advanced by Acemoglu, Kong and Ozdaglar (2026). Rather than reconstructing the formal apparatus or replicating its notation, we reposition the argument within three underutilized scholarly streams: the cognitive ergonomics of human-machine collaboration, the institutional ecology of knowledge stewardship, and the developmental psychology of novice expertise formation. We introduce a phase-space taxonomy that maps commons trajectories as functions of effort elasticity and knowledge complementarity, and we advance a governance typology calibrated to distinct cognitive levels - declarative, procedural, causal, and metacognitive. Drawing upon recent experimental evidence on neural offloading (Kosmyna et al., 2025), educational neuroscience (Lodge and Loble, 2026), and critical-thinking erosion under AI assistance, we argue that the collapse narrative, while theoretically coherent, overstates uniformity and understates adaptive capacity. The paper supplies a governance matrix organized by cognitive level and institutional lever. We conclude that the salient policy challenge is not the prevention of an inevitable collapse but the design of polycentric stewardship regimes that render the commons robust to heterogeneity in human responsiveness.