"The dark is generous.

Its first gift is concealment: our true faces lie in the dark beneath our skins, our true hearts remain shadowed deeper still. But the greatest concealment lies not in protecting our secret truths, but in hiding from us the truth of others.

The dark protects us from what we dare not know.

Its second gift is comforting illusion: the case of gentle dreams in nights embrace, the beauty that imagination brings to what would repel in day's harsh light. But the greatest of its comforts is the illusion that the dark is temporary: that every night brings a new day. Because it is day that is temporary.

Day is the illusion.

Its third gift is the light itself: as days are defined by the nights that divide them, as stars are defined by the infinite black through which they wheel, the the dark embraces the light, and brings it forth from the center of its own self.

Which each victory of the light, it is the dark the wins."

Matthew Stover
Star Wars Episode 3: Revenge of the Sith
The Novellization