Maybe the book is trying to tell us that there are good people and there are bad people. Humans have a choice, they can be good, and treat people fair, or they can be bad, and treat people like they are beneath them. Some slave owners treated their slaves somewhat well, while others were brutal. Frederick Douglass is obviously a good person, he struggled through slavery and still managed to become an abolitionist speaker. He battled on through every rough patch in his life, and in the end, he won the battle. He learned to read and he learned to write, and made something good of himself.