Dom Calmet, a specialist on the subject, explained that he was writing "on the apparitions of angels, demons and souls separated from the body".

[3] The Lalande dictionary follows suit: "God, angels, demons, disembodied souls of people after death are the spirits".

Hesiod was the first to set forth clearly and distinctly four classes of rational beings: gods, demigods, heroes, in this order, and, last of all, men; and as a sequence to this he postulates his transmutation, the golden race passing selectively into many good divinities, and the demigods into heroes.Pythagoras sees souls or spirits everywhere, as detached particles of the ether: The whole air is full of souls which are called genii or heroes.Pythagoras identifies four types of spiritual beings: gods, heroes, demons, and humans.

Honour likewise thy parents, and those most nearly related to thee.A little bit similar to Hesiod, in Timaeus, Plato mentions gods, demons, inhabitants in the Hades, heroes and humans of the past.

The Romans admitted gods, goddesses, masons (souls of the dead), lares (tutelary spirits protecting houses, etc.

[citation needed] The Neoplatonist Porphyry of Tyre (c. 260) carefully asks how to distinguish high-ranking divine beings (gods, archangels, angels, demons, heroes, archons of the cosmos or matter) from mere souls, not to mention malignant spirits (antitheoi):[5] Thou inquirest concerning what reveals the presence of a god, an angel, an archangel, a demon, or some archon [planetary governor] or soul.

In a word, I pronounce that manifestations accord with their essences, powers, and activities… Of a single kind are the appearances of the gods; those of the demons are varied; those of the angels, simpler than those of the demons, but inferior to those of the gods; those of the archangels, closer to divine causes; as for those of the archons, if by that thou meanest the masters of the world who administer the sublunary elements, they are varied, but arranged in order.Pagan angels and archangels have Persian origin.

[citation needed] Saint Augustine equates angels with uncreated light, born of the Word; he believes that demons have celestial bodies; he considers fauns to be monstrous children between women and devils.

[citation needed] In the 5th century, Martianus Capella described a world inhabited by spirits, satyrs, etc: The places inaccessible to men are populated by a crowd of Longaevi who inhabit the forests, woods and sylvan sanctuaries, lakes, springs and rivers.In his Commentary on Timaeus (439), Proclus admits nine levels of reality: One, being, life, mind, reason, animals, plants, animate beings, and prime matter.

[citation needed] Michel Psellos, a great Byzantine scholar of the 12th century, lists six categories of demons in a famous treatise used by Ronsard: Treated by energy dialogue or devil's operation (translated 1511).

In his prose novel Merlin (7th to 8th century), Robert de Boron introduces his heroes as children of a virgin and a devil, who is therefore an incubus, a sexual demon.

These soulless men are first and foremost those of the four families who inhabit the four Elements: the nymphs, nymphae, daughters of the water; the sons of the earth, lemurs, who dwell beneath the mountains; the spirits of the air, gnomi; the genii of fire, vulcani.

They come into the world like insects formed in the mire [by spontaneous generation].The Germans developed an "astonishing proliferation of supernatural creatures:" primordial giants (who personified "the great supernatural forces"), dwarves (who "are the dead"), elves (alves), trölls ("gigantic dead"), landvaettir ("tutelary deities of places"), disir, fylgja ("female figure following or accompanying each human being and embodies his destiny"), hamr ("form that everyone carries and which escapes from its support"), hamingja (form applied to the entire family), hugr ("spirit of the world").

The air is full of an innumerable multitude of peoples [Sylphs] of human figure, a little proud in appearance, but docile indeed: great lovers of the sciences, subtle, officious to the wise, and enemies of the foolish and ignorant.

Their wives and daughters are male beauties, such as the Amazons are depicted... Know that the seas and rivers are inhabited as well as the air; the ancient Sages named Ondins or Nymphs this species of people...

As for the salamanders, fiery inhabitants of the region of fire, they serve the philosophers.Rationalist Descartes uses the physiological term "animal spirits" to refer to corpuscles composed of the "most vivid and subtle" parts of the blood, which move the body as they circulate from brain to muscle (Discours de la méthode, V) (1637).

The link which unites the soul and the body, a principle intermediary between matter and spirit.Edward Tylor, one of the founders of anthropology, introduced the concept of animism in 1871 to provide, according to him, "a rudimentary definition of religion," and he posits "the minimal definition of religion as the belief in spiritual beings, within the framework of evolutionism:"[9] I purpose here, under the name of Animism, to investigate the deep-lying doctrine of Spiritual Beings… Animism characterizes tribes very low in the scale of humanity, and thence ascends (...) into the midst of high modern culture.According to Pierre Alexandre, in Sub-Saharan Africa:[10] the somewhat vague term 'spirit' is used to designate a whole collection of immaterial entities, generally possessing a certain number of the attributes of the human person, but not all, and, first of all, no concrete bodily envelope... First of all, the 'spirits of the dead'... Another widespread category is that of 'bush spirits', frequent personifications of the forces of nature... Sahara, the fried (dangerous).

Alongside them are the Twins, who wield great power, and the 'dead', who demand sacrifices and offerings and exert a direct influence on the fate of the living.Concerning the Amerindians, according to A. Métraux: Some information has been gathered in the tropics about a maize spirit.

Most spirits are represented in human form, with somewhat monstrous features: they may be hairy, or have prominent eyebrows, or two heads; they may have no knee joints, or stick together like Siamese twins.

Shinto mythology distinguishes several kinds of kami, those reputedly "celestial" (amatsu-kami) like Amaterasu Omikami, and those qualified as "terrestrial" (kunitsu-kami) like Okuninushi no Mikoto.

Saint Augustine likened the demons of Greco-Roman paganism to fallen angels, rebelling against divine authority and wishing to lead man into evil.

[19] Auguste Comte's positivism, according to his law of three stages, brings belief in spirits into the most remote era or conception, that of the theological stage, more precisely into its second phase, polytheism, where "life is finally withdrawn from material objects, to be mysteriously transported to various fictitious beings, usually invisible, whose continuous active intervention henceforth becomes the source of all external phenomena, and even then of human phenomena.