Ghosts
 
Artist rendition of a ghost climbing a staircase.Main article: Ghosts
For believers, ghosts are generally seen to be the spirit or soul of a deceased person. Alternative theories expand on that idea and include belief in the ghosts of deceased animals. Sometimes the term "ghost" is used synonymously with any spirit or demon[, however in popular usage the term typically refers to a deceased person.

The belief in ghosts as souls of the departed is closely tied to the concept of animism, an ancient belief which attributed souls to everything in nature. As the nineteenth-century anthropologist James Frazer explained in his classic work, The Golden Bough, souls were seen as the creature within that animated the body.Although the human soul was sometimes symbolically or literally depicted in ancient cultures as a bird or other animal, it was widely held that the soul was an exact reproduction of the body in every feature, even down to clothing the person wore. This is depicted in artwork from various ancient cultures, including such works as the Egyptian Book of the Dead, which shows deceased people in the afterlife appearing much as they did before death, including the style of dress.

A widespread belief concerning ghosts is that they are composed of a misty, airy, or subtle material. Anthropologists speculate that this may also stem from early beliefs that ghosts were the person within the person, most noticeable in ancient cultures as a person's breath, which upon exhaling in colder climates appears visibly as a white mist This belief may have also fostered the metaphorical meaning of "breath" in certain languages, such as the Latin spiritus and the Greek pneuma, which by analogy became extended to mean the soul. In the Bible, God is depicted as animating Adam with a breath.

Numerous theories have been proposed by skeptics to provide non-paranormal explanations for ghosts sightings.Although the evidence for ghosts is largely anecdotal, the belief in ghosts throughout history has remained widespread and persistent.