them every day, as St. Augustine believes, there is no reason to doubt
of their knowing all the wants of mankind, or that they can, in order
to console and strengthen them, render their presence sensible to
them, by God's permission, without receiving an express command from
him on the subject; which may be concluded from what St. Ambrose says
on the subject of the apparition of angels, who are by nature
invisible to us, and whom their will renders visible. _Hujus naturae
est non videri, voluntatis, videri._[662]

"On the subject of demons, it is certain that their power was very
great before the coming of Jesus Christ, since he calls them himself,
the powers of darkness, and the princes of this world. It cannot be
doubted that they had for a long time deceived mankind, by the wonders
which they caused to be performed by those who devoted themselves more
particularly to their service; that several oracles have been the
effect of their power and knowledge, although part of them must be
ascribed to the subtlety of men; and that they may have appeared under
fantastic forms, which they assumed in the same way as the angels,
that is to say, in aerial bodies, which they organized. The Holy
Scriptures assure us even, that they took possession of the bodies of
living persons. But Jesus Christ says too precisely, that he has
destroyed the kingdom of the demons, and delivered us from their
tyranny, for us possibly to think rationally that they still possess
that power over us which they had formerly, so far as to work
wonderful things which appeared miraculous; such as they relate of the
vestal virgin, who, to prove her virginity, carried water in a sieve;
and of her who by means of her sash alone, towed up the Tiber a boat,
which had been so completely stranded that no human power could move
it. Almost all the holy doctors agree, that the only means they now
have of deceiving us is by suggestion, which God has left in their
power to try our virtue.

"I shall not amuse myself by combating all the impositions which have
been published concerning demons, incubi, and succubi, with which some
authors have disfigured their works, any more than I shall reply to
the pretended possession of the nuns of Loudun, and of Martha
Brossier,[663] which made so much noise at Paris at the commencement
of the last century; because several learned men who have favored us
with their reflections on these adventures, have sufficiently shown
that th