Neither Good, nor Evil, per se, is dealt with in this entry. The phrase good and evil describes a dynamic opposition which drives much fantasy, Supernatural Fiction and horror; the Good and the Evil themselves are seldom examined. In a manner which reflects his deep understanding of medieval Romance and Allegory, J R R Tolkien dramatizes the linkage – through vividly presented contrasts of character and Story and Land – in order to manifest his strong, conservative, Roman Catholic understanding of Good and Evil (a Parody of Good); but he also does so in order to tell a fine story. Many who have followed him, on the other hand, and who have transformed his Secondary World into Fantasyland, use the GAE contrast as a convenient Plot Device, which is generally colour-coded (> Colour-Coding) for ease of understanding. Heroes (until recently) tend to be "Aryan" in appearance, and Dark Lords tend to the swarthy.
Though the phrase implies an equal responsibility for turning the wheel of Story, in normal practice it is the Evil characters who erupt from their dark coverts or lands, avidly hungry to devour and waste the plenitude of the Good. In fantasy stories, Good reacts to Evil. [JH/JC]