What is the theme in Mark Twain's Letters from Hawaii by Mark Twain?

Progress is the main theme. Mark Twain is aware of Hawaii's history, both recent and ancient, and sees Europe's influence as generally beneficial. When addressing Hawaii's distant past, Twain is inclined to use words such as "barbaric" or "savage." Modern Hawaiians, in Twain's mind, are more civilized thanks to the efforts of Christian missionaries. While there is a sense that the author is aware that something has been lost to the Hawaiians, Twain clearly believes that natives are better for the Christian influence and is proud to see how far the Hawaiians have come.