Neurodegenerative diseases are conventionally conceptualized as molecular pathologies of protein aggregation. Yet this framework fails to explain the temporal disconnect between pathological load and clinical deterioration, the presence of significant amyloid burden in cognitively normal individuals, and the repeated failure of therapies targeting protein clearance alone. We propose the Multilevel Recursive Coherence (MRC) framework: healthy neural function emerges from sustained oscillatory coherence across organizational levels (molecular, cellular, network, systemic) that recursively validate each other. Neurodegeneration represents coherence breakdown—molecularly correct signals occurring in temporally desynchronized contexts. A critical finding strengthens this view: the therapeutic efficacy of 40~Hz gamma stimulation reflects the natural resonance frequency of cortical circuits, emerging from biophysical constraints including GABA\textsubscript{A} receptor kinetics and parvalbumin interneuron myelination. Human trials show reduced brain atrophy and preserved function over 6-month treatment. Independent autoimmunity research documents quantitatively parallel patterns—cellular heterogeneity, subpopulation-specific markers, desynchronization preceding pathology. Bayesian analysis indicates coincidental convergence probability $<10^{-5}$, validating MRC as domain-general principle. The framework generates falsifiable predictions and proposes a therapeutic shift: from molecular suppression to active re-synchronization of systemic coherence. Note on nomenclature: This framework was initially developed as "Multilevel Recursive Authentication" (MRA) in the context of autoimmune disease, where the metaphor of the immune system ``authenticating'' self versus non-self was natural. However, what we actually describe is a system of harmonic coordination within the organism, where different levels continuously sustain synchronization with each other; different modes of failure in this coordination may manifest as different pathological categories. The term \emph{coherence} captures this better: a relational, emergent property without arbiter. We therefore adopt ``Multilevel Recursive Coherence'' (MRC) as the framework's name, reflecting this broader ontological commitment.