Where sacrifice or death has not brought about such complete transfer or abduction of the soul to the fairy world, there is only a temporary absence from human society; and, meanwhile, the vacated body is under a fairy spell and lies ill, or unconscious if there is a trance state. If the body is an infant's, a fairy may possess it, as in the Chinese theory of demon-possession. In such cases the Celts often think that the living body is that of another child once _taken_ but since grown too old for Fairyland; though the rational explanation frequently is purely pathological. Looked at philosophically, a fairy exchange of this kind is fair and evenly balanced, and there has been no true robbery. And in this aspect of the changeling creed--an aspect of it purely Celtic--there seems to be still another influence apart from human sacrifice, soul-abductions, demon or fairy-possession, and disease; namely, a greatly corrupted folk-memory of an ancient re-birth doctrine: the living are taken to the dead or the fairies and then sent back again, after the manner of Socrates' argument that the living come from the dead and the dead from the living (cf. our chapter vii). In all such exchanges, the economy of Nature demands that the balance between the two worlds be maintained: hence there arose the theories of human sacrifice, of soul abduction, of demon or fairy-possession; and in all these collectively is to be found the complete psychological explanation of the fairy-changeling and fairy-abduction beliefs among ancient and modern Celts as these show themselves in the Fairy-Faith. All remaining classes of changelings, which fall outside the scope of this clearly defined psychological theory, are to be explained pathologically. MAGIC AND WITCHCRAFT The evidence from each Celtic country shows very clearly that magic and witchcraft are inseparably blended in the Fairy-Faith, and that human beings, i. e. 'charmers,' _dynion hysbys_, and other magicians, and sorceresses, are often enabled through the aid of fairies to perform the same magical acts as fairies; or, again, like Christian priests who use exorcisms, they are able, acting independently, to counteract fairy power, thereby preventing changelings or curing them, saving churnings, healing man or beast of 'fairy-strokes', and, in short, nullifying all undesirable influences emanating from the fairy world. A correct interpretation of these magical elements so prominent in the Fairy-Faith is of fundamental importance, because if made it will set us on one of the main psychical highways which traverse the vast territory of our anthropological inquiry. Let us, then, undertake such an interpretation, first setting up, as we must, some sort of working hypothesis as to what magic is, witchcraft being assumed to be a part of magic. _Theories of Modern Anthropologists_