The oldest literary evidence for the term "changeling" is found in a translation of the Psalms by the Benedictine monk Notker III. (c. 950-1022), where he paraphrases fremediu chint with Old High German wihselinc. From filii alieni Notker makes uuihselinga iudei, obviously meaning children foisted upon them. Consequently, this was a familiar idea in his time. In the St. Paul fragments Notker uses the word wehselkint.
Eike von Repgow (1180/90 to after 1233) mentions in his legal book Sachsenspiegel an altvil, which was explained as a mentally retarded person, probably erroneously as a bisexual person or, according to various derivations, as a changeling. In Middle High German the spellings wehselkint, wihselinc, wechseling, wehsel-balc and wehselkalp occur.
From the 11th century onwards, mental illnesses and physical ailments were increasingly explained by the work of demons as possession. Hildegard von Bingen (1098-1179) regularly attributed the properties of animate nature to devils, druids or witches in her magical and natural medical works. The church adopted pagan ideas and instead of the old demons now had devils and witches appear as antagonists of pious people. The substitution of elves for children was reinterpreted accordingly by church scholars.
The cardinal and crusading preacher Jacob of Vitry (1160/70-1240) warned in one of his sermons against the chamium (middle Latin, probably to cambio, "exchange"), a boy who would suck many nurses and still not grow. Jacob of Vitry wrote sermons for priests who were not so skilled in sermon delivery and recommended that they add a moralizing story at the end for the better understanding of the common people. His story of the changeling (chamium) was not intended as a concluding example, but as a testimony of faith to begin the sermon. The message to be conveyed was clear: the existence of the devil, proven in such a way, was to reinforce the Christian faith. Just as changelings and the devil were supposed to exist according to the testimony (testimonia) of church authorities, other stories contained, for example, the assertion that a half-eaten loaf of bread was not the work of mice but of the devil and that only God could guard against it.
Such sermons had far-reaching effects on medieval popular belief and contributed to making the phenomenon of changelings appear not only as an imagined reality, but also as a tradition going back a long way in history. Further discussion centered on whether changelings were only begotten by demons, or were demons themselves. The latter view was held, among others, by the Heidelberg theologian Nikolaus Magni von Jauer (c. 1355-1435). Thomas Aquinas (c. 1225-1274), in his influential demonological system, coined the belief that a changeling is begotten by the intercourse of an incubus with a woman. According to his theory, the incorporeal devilish spirit can take on a body, but the seed does not come from this body, but from a man with whom the devil had previously performed intercourse in the form of a succubus. As incubus, he transfers this seed, to which he adds his own demonic qualities, to the woman. Thus, the devil "...in the carnal intercourse with men ... first succubus, then incubus, that is, not a real father," because in general demons can occasionally take on a body but have no body of their own and cannot reproduce themselves.
In the early modern period, the Hexenhammer (Malleus maleficiarum), written in 1487 by the Dominican Heinrich Kramer, became the main work legitimising the persecution of witches. Until 1669, 29 editions were published. After the existence of witches had been proven by hair-splitting conclusions and fallacies, relentless action had to be taken against the denial of witchcraft, whereby the numbers of witches killed in Protestant and Catholic areas hardly differed. The work explained witchcraft mainly in terms of the wickedness of female nature and invoked, among other things, the case of the 56-year-old Angéle de la Barthe, who in 1275 had confessed to consorting with the devil every night and had been burned alive for it in Toulouse. She is said to have given birth to a monster with a wolf's head and a snake's tail. In order to feed it, she had to steal small children every night. The case only appears in a 15th century chronicle, but is not mentioned by any contemporary source. For this reason, and because the charge of devil's advocacy does not fit the time given, the account is considered by some historians to be fiction.
In the English-speaking world, the word for changeling appeared in 1555. Initially, it was used to describe children or adults who had been exchanged in some way without the involvement of demons. In another meaning, changeling stood for people whose psychological mood and opinion were constantly changing. In both cases, the word originally had nothing to do with popular belief. Only in a dictionary published in the mid-17th century does a change in meaning show up in the reference "idiot, see changeling." This was the name given to simple-minded women, and secondarily to men, who had no firm faith, and who would be persuaded by any false prophet or impostor. The Anglican bishop Samuel Parker (1640-1687) located the stupidity of a youth called a changeling in his brain function, whereby he was incapable of restraining his passions and appetites. In short, for Parker the changeling became the antithesis of the puritanical man who kept himself under control.
The dissenter Samuel Portage (1633-1691) first brought the devil into play. Religious sects in the 1640s and 1650s referred to mentally retarded or melancholic people as changelings who were possessed by the devil. Portage belonged to the mystical sect of the Behemists (named after their founder Jakob Boehme), who made contact with angels and identified devilish activity in everything inexplicable. For Behemists, the ideal human state on earth was attainable and at the same time the presence of the devil was a reality. In the long epic poem on creation, Mundorum Explicatio, Portage wrote about incubi who placed their seed in ancient witches by magical means. During the Restoration, the devil was a driving force behind the things of nature. Where in the medieval faith he had been under the close watch of God, he now developed a certain active life of his own. The devil made use of witches because he could not produce offspring in a direct way, and created the changelings to bring his devilish nature among men. The questions were generally about how the devil and the spirits did things, not about their basically acknowledged existence.
A rough list of physical characteristics is as follows: Changelings are misshapen, possess congenital abnormalities such as supernumerary fingers, consist only of a body without limbs, are of dwarfish stature, and in most cases are particularly ugly. Changelings have a large misshapen skull, a pale complexion, shaggy hair, fixed or squinting eyes, and are also weak and sickly. If they possessed a large goiter, they were considered to have keel goiter. Symptoms of disease described suggest hydrocephalus (hydrocephalus) or rickets (softening of the bones) caused by vitamin deficiency, which used to be common. Their mental characteristics are described as mentally retarded, little or no speech, lazy, untidy, neglected and restless.
