[Footnote 1: Magicians were able to command spirits to do their bidding, while sorcerers, though they could _summon_ demons, were obliged to obey them.]
It is only when we begin to investigate the origin of certain old customs and superstitions that we gain any real idea of how deeply rooted in men's minds during the Dark and Middle Ages was the fear of the supernatural, and particularly of evil spirits. To this day in Pembrokeshire, the cottagers, after the Saturday morning scrubbing, take a piece of chalk and draw a rough geometrical pattern round the edge of the threshold stone. This they do, not knowing that their ancestors thought it a sure way of keeping the Devil from entering the house. Another custom, often noticeable in country parishes, is the reluctance to bury the dead on the north side of the churchyard; this is because evil spirits were always supposed to lurk on that side of the church precincts.
For many centuries Christianity, at all events among the mass of the people, seemed powerless to raise the dark veil of superstition which the old pagan beliefs had spread over the world; and indeed in many countries--sometimes from ignorance, sometimes from motives of expediency--heathen traditions and practices were preserved, and merely transferred to a Christian setting. Particularly was this the case among the Celtic nations, whose Christianity must in the early ages have merely been grafted on the native Druid beliefs. For the material that the great Irish and Welsh missionaries had to work with was rough indeed; and any drastic attempt to impose a new system of religion on a horde of Celtic tribesmen would doubtless have ended in speedy disaster. So it is probable that St. Patrick and St. David and their evangelist successors, instead of bluntly denouncing the most cherished of the heathen legends, merely took and adapted them to their own teaching; giving them first a decent Christian garb. Two instances of evident adaptation are quoted by Mr. Elworthy, in his book "The History of the Evil Eye," where he remarks: "Here in Britain the goddess of love was turned into St. Brychan's daughter; and as late as the fourteenth century lovers are said to have come from all parts to pray at her shrine in Anglesey. Another similar example is found in the confusion of St. Bridget and an Irish goddess, whose gifts were poetry, fire and medicine ... almost all the incidents in her legend can be referred to the Pagan ritual."