Pseudo Dionysius the AreopagiteThinkers

Evil (n.) is ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠mere deprivation of good: all things that are, by the very fact that they are, are good; in so far as they are deprived of good, they neither are good nor exist.