In fact it was only sensible for monks to exercise due caution around demons, but that didn't mean a monk would necessarily flee from demons at the first sign of trouble either. After all, it had been known from the time of the earliest monks in Egypt that anyone aspiring to extreme holiness was likely to be singled out for demonic temptation; in this sense demonic assaults were a normal and expected hazard of the monastic profession. Later medieval monks and nuns, indeed anyone who aspired to live abstemiously, maintain chastity, and pray regularly tended to have more frequent and worse experiences of demons than ordinary householders. Of course they developed more ways of managing demonic behaviour too. Thus, despite the dangers, with due diligence and appropriate safety precautions, attempted demonic attacks could be reduced from something potentially deadly to the level of a dangerous nuisance for most monks most of the time.

Stories about demons abounded in many medieval monastic readings, and these stories helped monks and nuns to prepare themselves for the kinds of behaviours and activities of demons that we see in first person accounts of visionary experiences. The word “visionary” belies the fact that the demons often did what seemed to be quite physical things, moving objects and people, causing bodily pain and suffering, leaving visible marks. Demons might strike, whip or suffocate the holy man or woman. They might lift and carry individuals around, threatening to drop them from a height (colour plate 7). They could take the form of beasts including dragons, snakes and toads, black dogs, monstrous horses and other frightening or disgusting creatures, their animal forms also capable of bruising, biting, or strangling the hapless religious aspirant. Even without taking on palpable forms, they did emotional damage by tempting holy men and women to deadly sins of lechery, gluttony, pride, and despair.

Many of the behaviours just mentioned are reflected in the archetypal catalogue of demonic temptations in the life of St Anthony of Egypt, a desert-dwelling ascetic from the early fourth century, but his characterisations left a lasting imprint on the monastic literature. Similar tales of real demons are reflected in biographies and visionary accounts right through the later Middle Ages.