Abstract
This study examines the theoretical framework underlying the establishment of acupuncture-moxibustion and herbal medicine as core therapeutic modalities in Korean medicine, focusing on the structural logic of the Hado (River Diagram) and the concept of exterior-interior regulation. Rather than treating the Hado as a historical cause, this study employs it as an interpretive model to elucidate how the human body was conceptually organized into functionally distinct regulatory layers: a somatic regulatory system that responds to external stimuli and a visceral regulatory system that sustains internal physiological processes. Within this framework, acupuncture and moxibustion are understood as exterior regulatory techniques that modulate bodily responsiveness through somatic pathways involving the body surface, meridians, muscles, and neural networks. In contrast, herbal decoctions are interpreted as internal regulatory therapies that operate primarily through visceral processes mediated by digestion, metabolism, and systemic regulatory networks. This distinction reflects a functional differentiation of regulatory hierarchy rather than a material correspondence between therapeutic tools and the Five Phases. Analysis of classical medical texts further suggests that acupuncture-moxibustion and herbal medicine were applied in a coordinated yet non-overlapping manner, often structured according to a principal-assistant (master-guest) relationship depending on pathological conditions. By reframing their combined use as a structured regulatory strategy rather than an arbitrary combination, this study provides a theoretical foundation for the structured integrative application of therapeutic modalities in contemporary Korean medicine.