lifeforce

Lifeforce is a term used to describe the essential energy or vitality that characterizes living beings. It appears across scientific, philosophical, spiritual, and popular cultural contexts, where its meaning varies with the domain of discourse.

In historical biology, lifeforce is associated with vitalism, a doctrine that living organisms are governed by a non-physical force distinct from inanimate matter. Vitalist ideas declined as experimental biology demonstrated that life processes can be explained by chemistry and physics.

In contemporary science, there is no empirical entity known as lifeforce. Biological life is explained through cellular metabolism, genetics, energy transduction, and environmental interactions. The phrase is most often used metaphorically to signify vigor or the qualitative persistence of an organism.

In popular culture, lifeforce is a common trope representing energy that can be stored, transferred, or drained. It appears in fantasy, science fiction, and video games as a renewable resource, a soul-like essence, or a mystical life energy linked to health or immortality.

Related concepts include vitalism, chi/ki/prana, aura, and bioenergetics. The term lifeforce should be distinguished from scientifically defined energy forms such as chemical energy and metabolic energy, and from religious or spiritual notions of a life essence or soul.