In the biblical, Hellenistic (Greco-Roman cultural), and Islamic worlds of thought, the terrestrial realm was a world in which humans were limited by the factors of time, space, and cause and effect. The celestial realm, generally composed of seven heavens or spheres dominated by the seven then-known planets, was the realm of the divine and the spiritual. The subterrestrial realm was the area of chaos and the spiritual powers of darkness. At the highest level of the celestial sphere was the ultimate of the sacred or holy: e.g., Yahweh, the God of Judaism, whose name was so holy it should not even be spoken; Bythos, the unknowable beginning beyond beginnings of gnosticism; the heavenly Father of Christianity, known through his Logos (the divine Word, or Reason, Jesus Christ); and Allah, the powerful, the almighty, and the sublime God of Islam.
In order to reveal the purpose and destiny of humans—the highest beings of the terrestrial realm—the ultimate of the celestial sphere enabled humans, according to such views, to come to a knowledge of who they are, what is their origin, and what is their destiny through celestial messengers—angels. The message, or revelation, was usually focused on the identity of the source of the revelation—i.e., the ultimate being—and on the destiny of humans according to their response. Because of a cosmic rift in the heavenly sphere prior to the creation of the world or the announcement of the revelation, angels, depending on their relationship to the Creator, might attempt to deceive humans with a false revelation or to reveal the truth about humans’ true nature (or identity), origin, and destiny. Angels who attempt to pervert the message of the ultimate celestial being in order to confuse humans’ understanding of their present boundary situation as terrestrial beings or their destiny as supraterrestrial beings are malevolent in function—though not always termed demons. Included among such malevolent angels are the Devil of Christianity and Judaism and Iblīs (the Devil) of Islam, who, in the form of a serpent in the biblical story of the Garden of Eden—according to later interpretations of the story—attempted to disrupt humanity’s understanding of its creaturely boundaries, or limitations. He did this by tempting Adam and Eve to eat the fruit of the tree of knowledge of good and evil so that they might become like God (or the divine beings of the heavenly court). In Zoroastrianism the Evil Spirit (Angra Mainyu, later Ahriman) attempted—through subservient spirits such as Evil Mind, the Lie, and Pride—to deceive terrestrial humans so that they would choose a destiny that was subterrestrial—punishment in a chasm of fire.
In the aftermath of the 16th-century Copernican revolution (based on the theories of the Polish astronomer Copernicus), in which humanity’s view of the cosmos was radically altered—i.e., the earth was no longer seen as the centre of the cosmos but instead was seen merely as a planet of a solar system that is a very small part of a galaxy in an apparently infinite universe—the concepts of angels and demons no longer seemed appropriate. The tripartite cosmos—heaven above, earth in the middle, and hell below—appeared to be an anachronism.
With the emergence of modern Western psychology and psychoanalytical studies in the 19th and 20th centuries, however, the underlying principles of beliefs in angels and demons took on new meanings. Many Christian theologians found some of the concepts of psychoanalysis helpful in reinterpreting the meanings underlying primitive and traditional beliefs in angels and demons. The tripartite cosmos was remythologized into a tripartite structure of the personality—the superego (the restrictive social regulations that enable humans to live as social beings), the ego (the conscious aspects of human mental life), and the id, or libido (the psychic content related to the primitive instincts of the body, notably sex and aggression). Thus, demons—according to this reinterpretation—might well be redefined as projections of the unregulated drives of humans that force them to act only according to their own selfish desires, taking no account of their effects on other persons. From a social point of view, demons might also be defined as the environmental and hereditary forces that cause humans to act, think, and speak in ways that are contrary to the well-being of themselves and their communities. A 20th-century French writer, Denis de Rougemont, maintained in his book La Part du Diable (1942; The Devil’s Share) that the Devil and the demonic forces that plague the modern world can be well documented in modern society’s return to barbarism and inhumanity. In the 2nd century ce Clement of Alexandria, a Christian philosophical theologian, pointed toward a psychological interpretation of demonic forces by stating that humans are often captivated by the inner appetitive drives of their passions and bodily desires. The Freudian “myth” of the human personality and other psychological studies thus initiated a new dimension in the study of angels and demons. Medieval iconography, which graphically depicted angels and demons as hybrid creatures that often defied even the most vivid imaginations of the persons who viewed them, was supplanted by psychological, psychoanalytical, and modern mythological symbolism coupled with theological reflection. Relationship to views of a dualistic cosmos
In religious traditions that have viewed the cosmos in a dualistic fashion, such as gnosticism, angels were believed to be celestial beings who controlled certain spheres through which a soul was to pass as it freed itself from the shackles of its material existence. Knowledge of these angels and their names was a necessary prerequisite for achieving eventual union with the ultimate spiritual reality. Included among various lists of the seven angels ruling the seven planetary spheres are Gabriel, Adonai (Lord), Ariel (lion of God), and others. The angel of the creation of the world of matter, Yahweh (sometimes called the Demiurge, the Creator), was evil, in the gnostic view, not only because he was the Creator but also because he tried to keep spiritual persons from knowing their true origin, nature, and destiny.
Manichaeism, a dualistic religion founded in the 3rd century ce by Mani, an Iranian prophet, like gnosticism, divided the world into two spheres—Goodness (Light) and Evil (Darkness). These two principles are mixed in the world of matter, and the object of salvation is to unmix the material and the spiritual so that one may achieve a state of absolute goodness. Highest in the celestial hierarchy are the 12 light diadems of the Father of Greatness and the Twelve Aeons, the “firstborn”—angelic figures that are divided into groups of threes, surrounding the Supreme Being in the four quarters of the heavens. Because the Devil, the Prince of Darkness, desires the advantages of the kingdom of Light, in an ensuing battle between the celestial forces Light and Darkness are mixed, and the world of matter and spirit is created. Unaware of their spiritual nature and constantly tempted by the demons of the Prince of Darkness, humans are eventually led to understand their true nature through the activity of angelic beings called the Friends of the Lights and the Living Spirit and his five helpers: Holder of Splendour, King of Honour, Light of Man, King of Glory, and Supporter. Relationship to views of a monistic cosmos
Those who view the cosmos as basically monistic—as in Hinduism, Jainism, and Buddhism—generally have no belief in angels, who function mainly as revealers of the truth. This function is performed by other beings, such as avatars (incarnations of the gods) in Hinduism, Tirthankaras (saviours) in Jainism, or bodhisattvas (Buddhas-to-be) in Buddhism. Because such personages generally are viewed more in terms of exemplifiers of the holy life than as conduits of a revelation (except in the case of several avatars and bodhisattvas), they are not to be regarded in terms of the typical Western conceptions of angelic beings. These religions do, however, have widespread beliefs in demons. Belief in demons as common to all religious or mythological views about the cosmos