Threshold-Based Argument for Six Discrete Human Senses

Abstract

This paper proposes a revised taxonomy of the human senses grounded in perceptual‑threshold analysis. Building on the classical distinction between immediate (contact‑dependent) and mediate (distance‑dependent) faculties, I argue that (i) tactile perception fractionates naturally into two functionally distinct modalities – feeling (low‑threshold, passive reception) and touching (higher‑threshold, active exploration); and (ii) olfaction and gustation, though both chemoreceptive, diverge sharply in their minimum effective stimulus, with smell operating at a substantially smaller molecular‑count threshold than taste. Psychophysical, neurophysiological, and phenomenological evidence is synthesized to demonstrate that threshold magnitude – not merely anatomical locus or attentional state – warrants treating feeling, touching, smelling, and tasting as four discrete senses. The analysis yields a six‑member sensory set: feeling, touching, smelling, tasting, seeing, and hearing. Epistemological implications for theories of embodied knowledge are explored, and experimental protocols capable of empirically validating the proposed thresholds are outlined.