This point of view, presented by mediaeval and modern occult sciences and confirmed by Celtic and non-Celtic percipients, when considered in relation to its non-Celtic sources and then at once contrasted with ancient and modern Celtic beliefs of the same character which constitute it--to be seen in the above Gaelic and Brythonic manuscript and other evidence, and in Cædmon's theory that angels are small beings--plunges us into the very complex and extremely difficult problem how far fairies as pygmy spirits may be purely Celtic, and how far they may reflect beliefs not Celtic. The problem, however, is far too complicated to be discussed here; and one may briefly say that there seems to have been a time in the evolution of animism when the ancient Celts of Britain, of Ireland, and of Continental Europe too, held, in common with the ancient Greeks, Romans, and Teutons, an original Aryan doctrine. This doctrine, after these four stocks separated in possession of it, began to evolve its four specialized aspects which we now can study; and in the Irish Universities of the early Christian centuries, when Ireland was the centre of European learning, the classical and Celtic aspects of it met for the first time since their prehistoric divorcement. There, as is clearly seen later among the mediaeval alchemists and occultists, a new influence--from Christian theology--was superadded to the ancient animistic beliefs of Europe as they had evolved up to that time. _Conclusion_ The ethnological argument, after allowing for all its shortcomings, suggests that small-statured races like Lapps and Eskimos (though not necessarily true pygmy races, of whose existence in Europe there is no proof available) did once inhabit lands where there are Celts, and that a Celtic folk-memory of these could conceivably have originated a belief in certain kinds of fairies, and thus have been a shaping influence in the animistic traditions about other fairies. The animistic argument shows that pygmies described in Celtic literature and in Celtic and non-Celtic mythologies are nearly always to be thought of as non-human spirits; and that there is now and was in past ages a world-wide belief that the human soul is in stature a pygmy. The philosophical argument of alchemists and mystics, in a way, draws to itself the animistic argument, and sets up the hypothesis that the smallness of elves and fairies is due to their own nature, because they actually exist as invisible tribes of non-human beings of pygmy size and form. THE CHANGELING BELIEF