By St. Dionysius the Areopagite
But, neither are the demons evil by nature; for, if they are evil by nature, neither are they from the Good, nor amongst things existing; nor, in fact, did they change from good, being by nature, and always, evil. Then, are they evil to themselves or to others? If to themselves, they also destroy themselves; but if to others, how destroying, or what destroying?----Essence, or power, or energy? If indeed Essence, in the first place, it is not contrary to nature; for they do not destroy things indestructible by nature, but things receptive of destruction. Then, neither is this an evil for every one, and in every case; but, not even any existing thing is destroyed, in so far as it is essence and nature, but by the defect of nature's order, the principle of harmony and proportion lacks the power to remain as it was. But the lack of strength is not complete, for the complete lack of power takes away even the disease and the subject; and such a disease will be even a destruction of itself; so that, such a thing is not an evil, but a defective good, for that which has no part of the Good will not be amongst things which exist. And with regard to the destruction of power and energy the principle is the same.
