th with one's food, they
might enter while the mouth was opened to breathe. Exorcists were
therefore careful to keep their mouths closed when casting out evil
spirits, lest the imps should jump into their mouths from the mouths of
the patients. Another theory was that the devil entered human beings
during sleep, and at a comparatively recent period a king of Spain,
Charles II (1661-1700), kept off the devil while asleep by the presence
of his confessor and two friars.[9]

Shortly before the reign of Gregory, there came into vogue the fashion
of exorcising demons by means of a written formula rather than by the
earlier means of making the sign of the cross and invoking the name of
Jesus. The theory of demonology was never very clear nor consistent.
By some it was claimed that in the practice of the magical arts evil
spirits provided cure for sickness, others maintained that they could
not heal any diseases, and hence the true test of Christianity was the
ability to cure bodily ills. A compromise position was that demons
were only successful in eliminating diseases which they had themselves
caused. There was not a little doubt in some cases about the character
of the possessing spirits, and it behooved people to be careful;
demons might use men as habitations, and while posing as good angels
vitiate health and provoke disease.

At the beginning of the seventh century, we have an account of an
exorcism by St. Gall (556-640), and during the Carlovingian age the
healing at Monte Cassino was based on the Satanic origin of disease.
When the conversion of northern races to Christianity began,
demonology received a stimulus. An unlimited number of demons, similar
in individuality and prowess, were substituted for the pagan demons,
and the pagan gods were added as additional demons. When proselytes
were taken into the church, care was taken to exorcise all evil
spirits. During the baptismal service the Satanic hosts, as
originators of sin, vice, and maladies, were expelled by insufflation
of the officiating clergyman, the sign of the cross, and the
invocation of the Triune Deity. The earliest formulas for such
expulsion directed a double exhalation of the priest.[10]

In all epidemics of the Middle Ages, such persons as were afflicted by
pestilent diseases were declared contaminated by the devil, and
carried to churches and chapels, a dozen at a time, securely bound
together. They were thrown upon the floor, where they lay, ac