/summa/SS/SSIV/SS_Q172:
We must now consider the cause of prophecy. Under this head there are six points of inquiry:
(1) Whether prophecy is natural?
(2) Whether it is from God by means of the angels?
(3) Whether a natural disposition is requisite for prophecy?
(4) Whether a good life is requisite?
(5) Whether any prophecy is from the demons?
(6) Whether prophets of the demons ever tell what is true?