In The Doors of Perception, 1954, Aldous Huxley, on mescaline, adopted the filter theory he credited to the Cambridge philosopher C.D. Broad endorsing Henri Bergson: the function of the brain and nervous system and sense organs is in the main eliminative and not productive, each person being at each moment capable of remembering all that has ever happened to him and of perceiving everything that is happening everywhere in the universe, the brain shutting out most of it, leaving only that very small and special selection likely to be practically useful. Mind at Large, funneled through the reducing valve, comes out the measly trickle of consciousness which will help us to stay alive. The documented lineage runs deeper: the theory descends from F.W.H. Myers's filtration model of the 1890s, William James's transmission theory, and forward to the current filter-theory literature, Woollacott and the postmaterialist shelf, this wing's other entries, carrying the same model with EEGs.
The folk tradition of the valve is the archive's Chemical Muse file formalized: mescaline opened Huxley's, meditation opens the meditators', the near-death experience opens it by shutting the brain down, the documented 12 percent of cardiac arrest survivors reporting hyper-aware experience during flatline being the modern literature's favorite datum, and the tradition's reading is uniform: whatever reduces the filter reveals the ocean. The tradition's own documented caution: the psychedelic valve-opening can also be read as the brain making errors, the filter theorists' answer being the specificity problem, the visions' recurring architecture, jewels, lights, presences, being too consistent across centuries for static, the archive's Ouija and The Doors files both holding pieces of this one.
The claim: the reducing valve is the archive's master key to its own pleroma and matrix wings, the gnostics' kenoma being the filtered world, the Bardo's clear light being the unfiltered one, the Demiurge's creation being, in filter language, a valve with a throne on it, and every enlightenment vocabulary on record being a description of the filter relaxing, the archive's note being that the oldest heresies and the newest neuroscience use the same plumbing. Verdict: the archive files the convergence without settling it: the valve theory explains the consistency of the mystical record as contact; the production theory explains it as malfunction; and the documented tiebreaker, content that outlives the brain, is precisely what this wing's Stevenson entry spent fifty years collecting. The trickle is measurable. The ocean is reported. The valve, per Huxley, is adjustable. The archive's readers are, per the tradition, the adjustment. Turn carefully, and cite the plumber.
If the brain's function is to shut out reality, what is reality before the shutting, and what opens the valve without breaking it?