Soul Magic
Soul magic is a generalised term for a collection of study, abilities, and known phenomenon that often intersect or relate to each other. It is a very hard thing to study, as it involves interaction with the non-physical elements of the world and studying a soul within the body poses a risk to life, and so the majority of knowledge on soul magic is simply documentation and theories without practical tests.
Because of how little study has been fully completed on soul magic, it is difficult to categorise the different kinds of soul magic accurately. This means that information about it has come to be lumped together under one compendium, even if they should, perhaps, be their own fields of study.
Ghost-Seeing Abilities
The most commonly recognised form of soul magic is the ability to see and/or hear ghosts. Some people are born with this ability, while others may have to find a way to channel their inner-magic or use other sources of magic to make communication with spirits easier.
Some individuals will witness spirits in their own unique ways, though the most common for those born with the ability is to see them as if they were walking the physical word as people. Sometimes, depending on the power of the person seeing the spirits and whether or not the spirits are wanting to be seen or remain hidden, these visions may be hazy or somewhat transparent; seemingly only partially there.
It is well-known and documented that grief acts as a block for seeing spirits, though it is not known why this occurs. Even for those with strong spirit-seeing abilities, the more a person grieves, the more difficult it becomes for them to communicate with the spirit of the person they wish to see.
It can be difficult for some people to tell spirits apart from physical reality, and because of the complications this causes it is not uncommon for those who see ghosts to be misdiagnosed with neurological disorders that cause hallucinations or those with a disorder to be misdiagnosed with the ability to see spirits.
Soul-binding
Soul-binding is a theory that has not yet been proven real, but many claims of soul-binding have been documented over the years and the general public tends to lean positively on the belief of it being a true phenomenon.
It is best described as the tangling of two souls; when people spend so much time together and care so deeply for one-another, that they are able to feel each other’s presence and mood even while apart. Even those without known telepathic powers are often able to sense each other’s thoughts and emotions as if they were speaking them aloud.
Research on cases of soul-binding seem to indicate it could be a trauma response, as a large amount of documented cases of people who claim to be soul-bound involve people who went through extended periods of trauma together and relied on each other for support during this strenuous time.
The connection found between soul-bound people is accepted to be, more often than not, platonic and not romantic. Though it is not unheard of for adults to become soul-bound, it is more common in children and the vast majority of cases involve siblings, especially twins, or friends whose families spent a large amount of time together. This bond created in childhood lasts throughout adulthood.
PDCS Theory
PDCS (Possession, Destruction, and Creation of Souls) theory is a touchy subject in many academic spaces, with many conflicting opinions on the specifics of how souls function.
However, the most commonly accepted and up-to-date theory is as simple as: The soul and the body are separate entities that exist together in symbiosis. While it is possible for one to exist without the other, it is a very unhealthy state for either to be in.
Viewing the body and soul as different-but-connected entities is the basis of PDCS research, and it is an important thing to consider when discussing topics such as permanent memory loss, dissociative identity disorders, and the undead.
It is believed that severe and permanent memory loss, especially caused by physical trauma, is a symptom of the soul being expelled from its body as it would have been upon death. The body, however, is left alive with trace amounts of the soul it used to have remaining within it. These trace amounts of soul are able to grow into a new soul, creating a similar-but-different person. This process is believed to be closely related to how the soulless undead are created; though, for soulless undead, it is thought that the soul of a person must be completely removed with no remaining pieces to grow back from; an irreversible form of damage.
Likewise, it is possible for souls to remain trapped in a body upon the body’s death; creating undead such as zombies. The soul trapped within the rotting body will begin to rot and decay just like its flesh, eventually being completely destroyed. Though some scholars have attempted to study the decay of souls, public outcry about the ethics of allowing a soul to rot has lead to difficulties doing so.
The study of soul destruction is heavily regulated, as it is very difficult to study without the risk of becoming unethical; discoveries related to soul destruction are opportunistic, rarely set up but heavily documented when witnessed.
There is also the belief that it is possible for a body to house more than one soul at a time. Originally, this course of study focused on spiritual possession by the undead; but over time it expanded to include other non-supernatural causes of bodies containing traces of multiple souls, such as the absorption of twins in the womb and dissociative identity disorders.
There is also evidence that possession is not always caused by the undead; there are some cases of people being possessed by other living people, or of souls switching bodies, though the details are extremely vague and not much is understood about these rare events.