In contrast to other demonic entities that roam the world of the Chronicles of Darkness, mages have a unique source of encountering these creatures. The Ars Goetia, often simply called Goetia, is a specialized form of magic that allows a mage to communicate with his baser self: his Vices. Goetia demands at least the third level of the Mind Arcanum.
According to legends, the practice of the Ars Goetia date back to King Solomon. Of all Paths, Mastigos are most inclined to take up the mantle of the Goetist, no doubt inspired by their trip to Pandemonium and their command of the Mind Arcanum. A Legacy, the Clavicularius, have risen around the practice of summoning and communicating with one’s darker impulses.
By meditating on the failures of his past, the goetic mage hopes to gain power over forces within that led to breakdowns or incidents of outright abuse. This introspection is not an easy or pleasant practice, and is not without risks. When a goetic mage fails to conquer his own weakness, he may unleash his inner demons on the world. As a result, most practitioners of Goetia are rigorously self-controlled and prone to long psychical evaluations of their own mind in order to minimize the dangers.
Experts in the occult sciences insist that inner demons exist either in the Temenos (the collective unconscious) or in a mage’s Oneiros (his personal dream space). They represent aspects of the mage’s own identity, not just sin, but failings or denied emotions. The simplest ones to understand represent the self-destructive or vainglorious side of a mage’s personality, a doppelganger to his civilized self. An inner demon can be empowered by the depression that seizes a mage in the middle of the night, by the jealousy that consumes him when he doubts those who love him, or by the shame that surfaces after he fulfills his desires. Before inner demons are given form and power, they are merely repressed thoughts and emotions.
A demon summoned via Goetia lacks any infernal traits, like hooves or bat wings. Instead, they resemble persons from the mind of the mage who originally summoned them. Perhaps they appear as a lover the mage has spurned, as a more self-confident and powerful version of their summoner without moral inhibitions, or like someone the mage has envied or lusted after from afar. Correctly summoned, a Goetic demon has to answer to their summoner and is forced to serve him. Many Goetists do so in order to analyze and decipher the sources of their bad habits and destructive urges and how to best solve them, but others have darker inclinations. A master of inner demons can bind Sleepers to his will by manipulating them with the same dark emotions he knows intimately. A person possessed by a goetic mage’s demon often displays the Vice and derangements of the mage who controls the entity. Scientific mages claim that modern techniques of psychotherapy can permanently cure a person who is possessed by a mage’s inner demons. Religious ones rely on old-fashioned exorcisms. Physically gifted mages swiftly subdue and restrain the goetic mage’s manifested minions.
Goetic demons dwell on no plane of existence known to mages, but can manifest in Twilight as well as in the Material World. There are only three ways of destroying a Goetic demon: a successful abjuration by its summoner, raw magical force, or a solution to the emotional problem that originally birthed the demon. If the host of a Goetic demon dies, the creature is free to roam Astral Space and the Material World of its own volition.