Within the framework of Qi philosophy, vital energy is regarded as the fundamental life force that both constitutes and animates living beings. It is not merely an abstract power added to an already-formed body; rather, it is the very principle that distinguishes life from death and sustains all physiological, emotional, and mental functions. This energy permeates the entire being, linking body, mind, and spirit into a single, integrated system, and at the same time connecting each living entity with the wider environment and cosmos.

Qi is understood as inherently dynamic, constantly flowing, transforming, and circulating rather than remaining static. In human beings, this movement is described as occurring through specific pathways or meridians, as well as through the organs and various forms of functional Qi. The quality of this flow—its smoothness, balance, and sufficiency—determines the state of health or illness. When Qi is harmonious and unobstructed, there is vitality, resilience, and emotional equilibrium; when it is blocked, deficient, excessive, or otherwise disturbed, weakness, disease, and psychological imbalance are said to arise.

This vital energy is also seen as existing in multiple forms and levels, some inherited and some acquired through breathing, nourishment, and ongoing interaction with the environment. Different manifestations of Qi govern different aspects of bodily and mental activity, yet all remain expressions of the same underlying life force. Living beings are therefore not isolated units but participants in a continuous exchange of Qi with nature, other beings, and the subtle forces that surround them. From this perspective, to understand a living being is to understand the patterns, qualities, and harmonies of Qi that animate and sustain its existence.