People who believed in the existence of fairies often did not always ascribe to them a definite origin, and explanations
varied culturally, regionally and temporally.
One popular belief was that they were the dead, or some subclass of the dead. The banshee, with an Irish or Gaelic name
that means simply, "fairy woman", is sometimes described as a ghost or as a harbinger of death. The Cauld Lad of Hylton,
though described as a murdered boy, is also described as a household sprite, like a brownie. One tale recounted a man caught
by the fairies, who found that whenever he looked steadily at one, the fairy was a dead neighbor of his. This was among the
commonest view expressed by those who believed in fairies, although many of the informants would express the view with some doubts.
Another view held that they were an intelligent species, distinct from humans and angels. In alchemy, in particular,
they were regarded as elementals, such as gnomes and sylphs, as described by Paracelsus. This is uncommon in folklore,
but accounts describing the fairies as creatures of the air have been found popularly.
A third belief held that they were a class of "demoted" angels. One popular story held that when the angels revolted, God
ordered the gates shut; those still in heaven remained angels, those in hell became devils, and those caught in between became
fairies. Others held that they had been thrown out of heaven, not being good enough, but were not evil enough for hell.
This may explain the tradition that they had to pay a "teind" or tithe to Hell; as fallen angels, though not quite devils, they
are subject to the Devil.
A fourth belief was the fairies were devils, entirely. This belief became much more popular with the growth of Puritanism.
The hobgoblin, once a friendly household spirit, became a wicked goblin. Dealing with fairies was in some cases considered a
form of witchcraft and punished as such in this era. Disassociating himself from such evils may be why Oberon, in A Midsummer
Night's Dream, carefully observed that neither he nor his court feared the church bells.
The belief in their angelic nature was less common than that they were the dead, but still found popularity, especially in
Theosophist circles. Informants who described their nature sometimes held aspects of both the third and the fourth view,
or observed that the matter was disputed.
A less-common belief was that the fairies were actually humans; one folktale recounts how a woman had hidden some of her children
from God, and then looked for them in vain, because they had become the hidden people, the fairies. This is parallel to a more
developed tale, of the origin of the Scandinavian huldra.
Sources of beliefs
One theory for the source of fairy beliefs was that a race of diminutive people had once lived in the Celtic nations and British
Isles, but been driven into hiding by invading humans. They came to be seen as another race, or possibly spirits, and were believed
to live in an Otherwold that was variously described as existing underground, in hidden hills (many of which were ancient burial
mounds), or across the Western Sea. Some archaeologists attributed Elfland to small dwellings or underground chambers where
diminutive people might have once lived. In popular folklore, flint arrowheads from the Stone Age were attributed to the
fairies as "elf-shot". The fairies fear of iron was attributed to the invaders having iron weapons, whereas the inhabitants
had only flint and were therefore easily defeated in physical battle. Their green clothing and underground homes were credited to
their need to hide and camouflage themselves from hostile humans, and their use of magic a necessary skill for combating those
with superior weaponry. In Victorian beliefs of evolution, cannibalism among "ogres" was attributed to memories of more savage
races, still practicing it alongside "superior" races that had abandoned it. Selkies, described in fairy tales as shapeshifting
seal people, were attributed to memories of skin-clad "primitive" people traveling in kayaks. African pygmies were put forth
as an example of a race that had previously existed over larger stretches of territory, but come to be scarce and semi-mythical
with the passage of time and prominence of other tribes and races.
Another theory is that the fairies were originally worshiped as gods, but with the coming of Christianity, they lived on, in a
dwindled state of power, in folk belief. Many beings who are described as deities in older tales are described as "fairies" in
more recent writings. Victorian explanations of mythology, which accounted for all gods as metaphors for natural events that
had come to be taken literally, explained them as metaphors for the night sky and stars.
A third theory was that the fairies were a folkloric belief concerning the dead. This noted many common points of belief, such as
the same legends being told of ghosts and fairies, the Sidhe mounds in actuality being burial mounds, it being dangerous to eat
food in both Fairyland and Hades, and both the dead and fairies living underground.