Section 34
On the Divine Names · Pseudo-Dionysius the Areopagite
The Evil, then, is not an actual thing, nor is the Evil in things existing. For the Evil, qua evil, is nowhere, and the fact that evil comes into being is not in consequence of power, but by reason of weakness. And, as for the demons, what they are is both from the Good, and good. But their evil is from the declension from their own proper goods, and a change----the weakness, as regards their identity and condition, of the angelic perfection befitting them. And they aspire to the Good, in so far as they aspire to be and to live and to think. And in so far as they do not aspire to the Good, they aspire to the non-existent; and this is not aspiration, but a missing of the true aspiration.
PdDN 4.34.1