Within the School of Yin–Yang, what is often called “energy” is understood as qi, a subtle, vital force that underlies and animates all existence. Qi is not merely physical power; it is the basic stuff of reality from which Heaven, Earth, and the myriad things arise. It is envisioned as a primordial life force that is constantly in motion and transformation, flowing in cyclical patterns and never truly created or destroyed, only changing form. In this view, the cosmos is not a collection of inert objects but a field of ceaseless energetic activity.

Yin and yang are regarded as the primary modes or polar aspects of this qi. Yin is associated with what is receptive, cool, dark, and contractive, while yang corresponds to what is active, warm, bright, and expansive. These are not fixed substances but relational qualities that define how qi manifests and behaves. Their interaction is dynamic rather than static: each depends on the other, generates the other, and together they drive all natural processes and transformations. All change is thus interpreted as the alternation, balance, and mutual transformation of yin and yang within the continuum of qi.

This energetic vision extends to cosmology, where celestial, seasonal, and earthly phenomena are seen as patterned movements of qi governed by yin–yang alternation. Day and night, summer and winter, growth and decline are understood as cyclical expressions of this underlying energy. The Five Phases (wood, fire, earth, metal, water) are treated as further modalities or phases of qi, shaped by and expressing the interplay of yin and yang. Through these phases, qi acquires specific qualities and patterns of interaction, giving structure to the myriad forms and processes observed in the world.

Human life, in this framework, is a localized condensation of the same cosmic qi. The body and mind are not separate from the larger cosmos but continuous with it, participating in the same energetic rhythms and transformations. Health, character, and the course of a life are seen as functions of how yin–yang qi flows and balances within a person in relation to broader cosmic cycles. Harmony arises when this flow is attuned to natural rhythms; disharmony appears when the balance of yin and yang qi is disturbed, giving a metaphysical grounding to both personal well-being and the wider order of the world.