Demonology is the study of demons or beliefs about demons, especially the methods used to summon and control them. The original sense of "demon", from the time of Homer onward, was a benevolent being, but in English the name now holds connotations of malevolence. Demons, when regarded as spirits, may belong to either of the classes of spirits recognized by primitive animism. That is to say, they may be human, or non-human, separable souls, or discarnate spirits which have never inhabited a body. For example, the Inuit are said to believe in spirits of the sea, earth and sky, the winds, the clouds and everything in nature. Every cove of the seashore, every point, every island and prominent rock has its guardian spirit. Traditional Korean belief posits countless demons inhabit the natural world; they fill household objects and are present in all locations. Greek philosophers such as Porphyry, who claimed influence from Platonism, and the fathers of the Christian Church, held that the world was pervaded with spirits, the latter of whom advanced the belief that demons received the worship directed at pagan gods. Many religions and cultures believe, or once believed, that what is now known as soothsaying, was, or is, a form of physical contact with demons.
The ascription of malevolence to the world of spirits is by no means universal. Demons are generally classified as spirits which are believed to enter into relations with the human race. Excluded are souls conceived as inhabiting another world. Belief in demons goes back many millennia. In Babylonian mythology, the seven evil deities were known as shedu, or "storm-demons". Traditionally, Buddhism affirms the existence of hells peopled by demons who torment sinners and tempt mortals to sin, or who seek to thwart their enlightenment, with a demon named Mara as chief tempter, "prince of darkness," or "Evil One" in Sanskrit sources. Demonic forces had attained enormous power in the world. Medieval Chinese Buddhist demonology was heavily influenced by Indian Buddhism. Indian demonology is also fully and systematically described in written sources, though during Buddhism's centuries of direct influence in China, "Chinese demonology was whipped into respectable shape," with a number of Indian demons finding permanent niches even in Taoist ritual texts. Therefore, depending on the context, in Buddhism demons may refer to both disturbed mind states and actual beings.
Christian demonology is the study of demons from a Christian point of view. In contrast, the early Enochic tradition bases its understanding of the origin of demons on the story of the fallen Watchers led by Azazel. Scholars believe these two enigmatic figures - Azazel and Satan exercised formative influence on early Jewish demonology. While historical Judaism never recognized any set of doctrines about demons, scholars believe its post-exilic concepts of eschatology, angelology, and demonology were influenced by Zoroastrianism. A number of authors throughout Christian history have written about demons for a variety of purposes. Theologians like Thomas Aquinas wrote concerning the behaviors of which Christians should be aware, while witchhunters like Heinrich Kramer wrote about how to find and what to do with people they believed were involved with demons. These latter texts were usually more detailed, giving names, ranks, and descriptions of demons individually and categorically. A few Christian authors, such as Jack Chick and John Todd, write with intentions similar to Kramer, proclaiming that demons and their human agents are active in the world. These claims can stray from mainstream ideology, and may include such beliefs as that Christian rock is a means through which demons influence people. Not all Christians believe that demons exist in the literal sense. Vedic Scriptures include a range of spirits (Vetalas, Rakshasas, Bhutas and Pishachas) that might be classified as demons. These spirits are souls of beings that have committed certain specific sins. Hindu text Atharvaveda gives an account of nature and habitats of such spirits including how to persuade/There are occult traditions in Hinduism that seek to control such spirits to do their bidding. Hindu text Garuda Purana details other kinds of punishments and judgments given out in Hell; this also given an account of how the spirit travels to nether worlds.
Islam has no doctrinal hierarchy of demonology. Even though some Muslim scholars tried to classify jinn and demons, there is no established classification and terms on jinn may overlap or used interchangeable. Naming the Jinn also depends on cultural influences. Julius Wellhausen states, that Islamic demonology is also zoology. Many demonic or demon-like entities are not purely spiritual, but also physical in nature and related to animals. Marid: Si'lahA female demon, seducing men. Spirits dwelling in houses. The name for a specific demon struggling children. A Ghul in Arabic meaning, terms any shapeshifting spirit, including the Si'lah. Judaism does not have a demonology or any set of doctrines about demons. There is more than one instance in Jewish medieval myth and lore where demons are said to have come to be, as seen by the Grigori angels, of Lilith leaving Adam, of demons such as vampires, unrest spirits in Jewish folklore such as the dybbuk.
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