What is the theme in The Sword of Shannara by Terry Brooks?

One of the main themes of quite a few books, especially fantasy novels, is about normal people being forced into a quest to save others. Typically, this is due to circumstances around their birth or heritage. In Sword of Shannara, the main protagonist, Shea is the only living direct descendant of the famous King of Shannara. If Shea does not find the Sword of Shannara, his family, friends, and entire land will be destroyed.