I’ll talk specifically about magic, but what we would call the ‘supernatural’ was an accepted fact of everyday life for almost everyone in the pre-modern world, and medieval Europe was no exception. In fact, what we would consider as ‘supernatural’ was so tied into the fabric of the pre-modern consciousness that it may be problematic to uncritically impose what we understand to be the ‘supernatural’ on pre-modern beliefs at all; for some medieval theologians like Thomas Aquinas (IIRC), the only thing that could be considered supernatural or above-nature was God himself; every other belief or action that we would deem supernatural would have consequently appeared as part of the natural world.

Now to talk a bit about magic. In a very basic definition, magic is the use of rituals, incantations, items etc. to coerce a ‘supernatural’ force into helping you. This may include a very wide range of activities, from the use of white magic to find lost items or treasures, the totemic veneration of saints with the purpose of provoking their intervention, fertility rituals or love spells. Popular Christianity was essentially magical: for example, people would steal the Host from Mass to use as a magical talisman for any number of purposes. These beliefs were so pervasive that the Church attempted to establish a monopoly over religious magic through the form of the cult of saints: saints and their relics were seen as potent suppositories of magic and more importantly, direct intercessionaries between humanity and divine power.

Saints from the early medieval period often filled the void left by pagan heroic figures – in the Irish context saints like Patrick and Columba popularly appear as figures who wield divine power as a form of powerful magic – and decidedly not a kind of religious supplication - used to vanquish their enemies. The two aforementioned saints sometimes unashamedly take on the roles of pagan warrior-heroes; in several accounts they (especially Patrick) slay lake-monsters through the use of divine magic dying the body of water red with its blood, a trope taken from earlier heroic narratives. Indeed, in one toponymical text, this trope is performed by a pagan god!

Almost every problem that a medieval person had could have a magical solution. But why was magic such a fundamental feature of the medieval world and indeed across all human societies? The historian Aron Gurevich has argued that for pre-moderns, the cycles of nature were not self-evident – for them, at least initially, it was not assured that their crops would grow again or that the moon would return after an eclipse. As a consequence, people sought ways of controlling the natural world which was done through magic. In fact, this was more than just control, it was participation with the cosmos - the natural world could evidently influence human affairs and natural processes: the sun could make snow melt, flowers bloom or bodies sweat; the rain could make crops grow or clay melt. If humans were a part of the natural world, and the natural world had such an evident power over things, then why shouldn’t humans be able to influence the world around them in the same way? This is the logic behind magic: humans were made of the same elements as the natural world and each could influence the other, it was the instinctive way of confronting nature for people who lacked complex scientific or technical knowledge.