effectively

In my opinion, however, it is certain wicked demons, and, so to speak, of the race of Titans or Giants, who have been guilty of impiety towards the true God, and towards the angels in heaven, and who have fallen from it, and who haunt the denser parts of bodies, and frequent unclean places upon earth, and who, possessing some power of distinguishing future events, because they are without bodies of earthly material, engage in an employment of this kind, and desiring to lead the human race away from the true God, secretly enter the bodies of the more rapacious and savage and wicked of animals, and stir them up to do whatever they choose, and at whatever time they choose: either turning the fancies of these animals to make flights and movements of various kinds, in order that men may be caught by the divining power that is in the irrational animals, and neglect to seek after the God who contains all things; or to search after the pure worship of God, but allow their reasoning powers to grovel on the earth, and amongst birds and serpents, and even foxes and wolves. For it has been observed by those who are skilled in such matters, that the clearest prognostications are obtained from animals of this kind; because the demons cannot act so effectively in the milder sort of animals as they can in these, in consequence of the similarity between them in point of wickedness; and yet it is not wickedness, but something like wickedness, which exists in these animals.

Having completed seven books, I now propose to begin the eighth. And may God and His only-begotten Son the Word be with us, to enable us effectively to refute the falsehoods which Celsus has published under the delusive title of A True Discourse, and at the same time to unfold the truths of Christianity with such fulness as our purpose requires. And as Paul said, “We are ambassadors for Christ, as though God did beseech you by us,” so would we in the same spirit and language earnestly desire to be ambassadors for Christ to men, even as the Word of God beseeches them to the love of Himself, seeking to win over to righteousness, truth, and the other virtues, those who, until they receive the doctrines of Jesus Christ, live in darkness about God and in ignorance of their Creator. Again, then, I would say, may God bestow upon us His pure and true Word, even “the Lord strong and mighty in battle” against sin. We must now proceed to state the next objection of Celsus, and afterwards to answer it.