French writer Claude Seignolle confirms that this folklore is based upon stories of criminals cursed by priests, causing them to become werewolves. Other writers assure that the werewolf stories are originated in cases dealing with demonic possession. To many sixteenth and seventeenth century experts, a witch could become a werewolf only by the means of dealing with the Devil. These "witches" were usually believed to have no other supernatural ability. Many contemporary werewolf legends are originated in that obscure era. All these popular beliefs are so rooted into our culture that it is difficult to tell where the boundary between myth and reality is.

However and as highlighted before, It is possible to find many ways to become a werewolf that do not require to deal with the Devil. In Italy, the common belief is that anybody who is born on a full moon Friday, or who sleeps outdoors during one of those days, is prone to become a werewolf. In the Balcanic Peninsula, where the famous Transylvania is located, grows a flower that, people say, if eaten, causes the eater to acquire Lycanthropy. To drink from the water filling a wolf track or from where a wolf pack has drunk, or to eat the brains of a real wolf are other popular ways still believed in Europe to become, accidentally or intentionally, a werewolf.

Some lycanthropes (according to tales from the 17th century) assured people that they really were wolves and that their fur grew inside their body. If we remember the drugs used by witches as "metamorphosing ointments" and self-suggestion, it is very possible that this induced, in the ones who took them, hallucinations of being werewolves, without really being affected by lycanthropy, only by the effects of such drugs combined with suggestion.

Indeed, the power of transforming others into wild beasts was attributed not only to sorcerers, but also to Christian saints.

Omnes angeli, boni et mali, ex virtute naturali habent potestatem transmutandi corpora nostra ("All angels, good and bad have the power of transmutating our bodies") was the dictum of St. Thomas Aquinas.

St. Patrick transformed Vereticus, a king in Wales, into a wolf; and St. Natalis cursed an illustrious Irish family with the result that each member of it was doomed to be a wolf for seven years.