Soul

A soul was a non-corporeal aspect of a person's essence, generally thought to leave the body at the time of death.

The Fourth Doctor explained the soul or life force as "the full spectrum of energy." (TV: Image of the Fendahl)

Nature
According to the Eleventh Doctor, souls were made of stories, not atoms. (TV: The Rings of Akhaten) The soul was sometimes synonymous with a person's mind, their soul being composed of their memories, but even this was not considered accurate. However, the removal of a person's mind to another plane could simulate death, leading to the allusion between a soul and a mind. (PROSE: Timewyrm: Revelation, Falls the Shadow)

The Fendahl absorbed souls and left blisters on the back of its victims' necks, afterwards their bodies would rapidly decompose. Maximillian Stael described it as all the energy being removed: "All the binding force has gone and all that remains is a husk." (TV: Image of the Fendahl)

Due to being "half-dead" in some metaphysical sense, Origin Zero had the ability to see souls. This allowed her to confirm that the Morch'aliach did indeed trap the souls of the dead within itself, rather then creating mere simulacra. The many souls it had trapped were stuck telling the stories of their own deaths on a loop, which sustained Morch'aliach's existence and helped it deter others from attacking it. The souls were released after P.R.O.B.E. and Ganeida destroyed Morch'aliach. (PROSE: A Honeycomb of Souls)

The souls of the dead passed through the Moon's influence on their way to Heaven, where they were sometimes caught by the Lunaries and offered new bodies. Leonardo da Vinci and Roger Bacon were two such persons who accepted, and by 1590 were still living there. (PROSE: Minions of the Moon)

In the 22nd century, some artists used soul extractors to improve their art, literally extracting portions of their souls and inserting them into the canvas. They used it sparingly, as the results of over-use were lethal. One time when an artist became addicted, he created a living being within the canvas. (PROSE: Untitled)

Death attempted to collect thirteen souls in order to fully enter our reality. He was stopped by Owen Harper at twelve. (TV: Dead Man Walking)

The neutron eaters tricked Oliver Harrington into bringing more of them through from their dimension by making him think that angels were souls, returning from Heaven to the mortal world. (AUDIO: Lost Souls)

In 2013, Rosemary Kizlet scavenged the Wi-Fi to upload the souls of humans to feed to her client. (TV: The Bells of Saint John)

Human
The Soulless were a group that arose during the Miracle Day event, which had rendered virtually all humans on Earth incapable of dying. Members of the Soulless believed that because they could not die, they had been robbed of their souls. (TV: Dead of Night)

Gallifreyan
The Time Lords had a rite called Soul Catching, in which a dying Time Lord would transfer his soul to another Time Lord, which would then get assimilated into the Matrix. (PROSE: The Devil Goblins from Neptune)

The early Time Lords under Rassilon`s leadership removed the irrational parts of their souls to create a more rational universe. These removed parts then formed into a gestalt of superstition that eventually became the entity known as the Carnival Queen, the living personification of the Time Lords` irrationality. (PROSE: Christmas on a Rational Planet)

The Eighth Doctor claimed that if he looked into the Eye of Harmony, his soul would be destroyed, and would be able to take over his body. (TV: Doctor Who)

Aplan
The Aplans believed that, after death, their souls ascended through six levels to their version of the afterlife. They dedicated Mortaria to this. (TV: The Time of Angels)

Dalek
According to Rusty, the Daleks didn't have souls. (TV: Into the Dalek)

Davros, however, created a clone body and planned to transfer his history, intelligence, and life, to which the Eighth Doctor considered his "soul.' (AUDIO: Terror Firma)

Rhodian
The Cabinet of Souls contained the souls of the Rhodian people after their deaths. Each soul, compressed into a speck of light, could also be used to kill an individual (TV: For Tonight We Might Die) by burning their soul out of existence, burning themselves out in the process. According to Charlie Smith, in the hands of a hero, the souls would take over bodies instead of just burning them. (TV: Co-Owner of a Lonely Heart) The souls were eventually used to destroy the Shadow Kin. (TV: The Lost)