Moreover, if it is believed not only among Christians and Jews, but also by many others among the Greeks and Barbarians, that the human soul lives and subsists after its separation from the body; and if reason supports the idea that pure souls which are not weighed down with sin as with a weight of lead ascend on high to the region of purer and more ethereal bodies, leaving here below their grosser bodies along with their impurities; whereas souls that are polluted and dragged down to the earth by their sins, so that they are unable even to breathe upwards, wander hither and there, at some times about sepulchres, where they appear as the apparitions of shadowy spirits, at others among other objects on the ground—if this is so, what are we to think of those spirits that are attached for entire ages, as I may say, to particular dwellings and places, whether by a sort of magical force or by their own natural wickedness?
Are we not compelled by reason to set down as evil such spirits as employ the power of prophesying— a power in itself neither good nor bad— for the purpose of deceiving men, and thus turn them away from God, and from the purity of His service? It is moreover evident that this is their character, when we add that they delight in the blood of victims, and in the smoke odour of sacrifices, and that they feed their bodies on these, and that they take pleasure in such haunts as these, as though they sought in them the sustenance of their lives; in this resembling those depraved men who despise the purity of a life apart from the senses, and who have no inclination except for the pleasures of the body, and for that earthly and bodily life in which these pleasures are found.
If the Delphian Apollo were a god, as the Greeks suppose, would he not rather have chosen as his prophet some wise man? Or if such an one was not to be found, then one who was endeavouring to become wise? How came he not to prefer a man to a woman for the utterance of his prophesies? And if he preferred the latter sex, as though he could only find pleasure in the breast of a woman, why did he not choose among women a virgin to interpret his will?
Source: Against Celsus (New Advent)