Life Force

The Life Force (alternatively named Life Energy, Vital Force, Chi, Azoth, Prana, or simply Energy) is an occult substance tied to the state of being alive, generally considered to be a subject of mysticism instead of science in modern times. It is commonly treated as a synonym for the soul. Some theories describe multiple types of soul that handle successively higher forms of existence; corresponding to modern ideas of a life/sentience/sapience hierarchy, so the soul inherent to every living creature can fit the definition of a life force. If possession of any soul requires all souls of a lower type, this would explain the idea that artificial intelligences lack a soul, being deprived of the most basic measure of life force, although the modern conception of AI is much newer than stories where life forces are directly used to create artificial intelligence. That said, life force often exists independently of living beings, following an ecological cycle like life's other materials where it is released and concentrates in different parts of the world, benefitting those that are better at accumulating it. An abundance of life force can be the source of other supernatural properties, but many supernatural beings will still have power over it if this isn't the case.

Transferring Life Force
The concept of life essence, life force or life energy is often present in science fiction and fantasy. It usually consists of something which is inherently present in all life (or at least all organic life) and which can be transferred from one being to another by some means, typically weakening (or even killing) the donor and healing (or even reviving) the receiver.

The following species possess the natural ability to transfer their own life force to heal other creatures.
 * Anjurwans
 * Antareans
 * Asogians
 * Betelgeusians
 * Cimmerians / Solarians
 * First Born
 * Mothers

Conversely, some species have evolved to feed directly on life force.

A diminished life force can appear as lethargy, sickness, or aging. When lost entirely, the process can be simply described as the cessation of life, whether that means the loss of higher activity, biological function, or the body itself. It might be reversible by imbuing the victim with their lost energy, if their fate hasn't been an unnaturally thorough form of death.

Specific Depictions of a Life Force

 * Way Station Universe: Enoch Wallace has speculated that the mysterious golden haze emanated by the Hazers might actually be their life force, suggesting that they might "wear that life force on the outside of them", whereas other life forms "[wear] it on the inside".


 * Doctor Who Universe: In the late 19th century, time-traveler Magnus Greel used a machine to drain young women of their life essences in an attempt to heal his body after his metabolism was altered by zigma energy. The process kills the victims and leaves their bodies dry and brittle. The Fendahl is a creature that feeds on "the energy wavelengths of life itself", which the Doctor has also described as "what some people call a life force or soul". The Cimmerians heal the bodies of the sick and injured at the expense of their own life force.


 * Lost in Space Universe: The quintessence of all life is a substance known as cosmonium, which can be naturally found in its raw state on some planets, although very rarely. In this state, it can be extracted from the ground and stored like any common substance. Exposure to it can give life to an inanimate object such as a statue.


 * The Dark Crystal Universe: The Skeksis have developed a way to drain the life essence of other life forms, such as Gelflings and Podlings, in order to rejuvenate themselves. The drained victims remain alive in a zombified state.


 * Babylon 5 Universe: A mysterious machine created by an unknown alien civilization was designed to transfer life force from one individual to another, restoring the health of the receiver at the severe expense of the donor, to the point that it can easily result in death for the latter. The First Born seem to have the natural ability to do the same, using their own life essence to heal and even revive others from death, although there are limits. When Lorien revived John Sheridan, he was able to give Sheridan twenty more years, explaining that Sheridan would still die at the end of this period.


 * Ascendancy Universe: The Hanshak race is conscious of a reincarnating life force, which determines their political and religious leadership. The Shevar also know about the supernatural energies of life, but don't reserve any spiritual significance for living beings or their life force, they only see it as food.


 * Ben 10 Universe: Magic is the discipline of provoking supernatural events with the energy of life; mana. The ability to use magical powers is a hereditary oddity in the Human and Geochelone Aerio races, and universal within the race of pure mana lifeforms called Anodites. It is an extraordinary power, some energy manipulators like a Crystalsapien can do the most simple form of mana manipulation, but even the nearly omnipotent Celestialsapiens would have to fundamentally redesign the universe to let themselves control magic.