Sleep architecture research has a puzzle it hasn't fully solved: why do older adults — even cognitively healthy ones — lose slow-wave sleep decades before they lose anything else, and why does that loss track so precisely with next-day fluid reasoning? The neurologist and sleep researcher Matthew Walker has documented this in detail, but the interesting philosophical question it raises is one that the Jain doctrine of anekāntavāda — the principle that any phenomenon has irreducibly multiple valid aspects — handles better than most Western frameworks. Anekāntavāda holds that describing something from only one standpoint produces a partial truth that masquerades as a complete one. We treat brain health almost entirely through the lens of what we add: supplements, stimulation, learning challenges, novel inputs. But the Jain framework insists on accounting for the aspect of abhāva — absence, negation, the fact that what a system is not doing is as constitutive as what it is doing. Slow-wave sleep is the brain's great abhāva: a period of reduced metabolic noise during which the glymphatic system clears amyloid and tau proteins, synaptic weights are downscaled, and the cortex consolidates structure rather than accumulating it. The Jain logician Hemacandra argued in the twelfth century that any complete account of a thing must include a description of its dormant or withheld potential — what it is capable of that it is currently not expressing. A brain that never fully withdraws is not resting its capacity; it is slowly spending it. The practical implication is sharper than it sounds: your effort to protect cognitive longevity through active engagement is probably incomplete without an equally deliberate architecture of withdrawal — not just sleep duration, but the conditions that let deep sleep actually occur.

In the last month, have you changed anything about the conditions of your sleep — temperature, light, timing, substances — or only about the content of your waking hours?

Drawing from Jain philosophy (anekāntavāda / doctrine of many-sidedness) synthesized with sleep neuroscience — Hemacandra (Yogaśāstra, ~1175 CE) synthesized with Matthew Walker (Why We Sleep, 2017; Alzheimer's Disease, sleep, and the glymphatic system research)