What is the theme in A Wizard of Earthsea by Ursula K. Le Guin?

The theme of good and evil can be found throughout the novel "The Wizard of Earthsea" by Ursula K. Le Guin. Good and evil can be found in everyday life in every place, but it takes on an especial meaning in magic. The wizards speak of this as lightness and darkness—one cannot exist without the other. Taken together, balance is brought into the world by way of an eternal struggle between light and dark, and good and evil.