Douglass also portrays slavery as emasculating. There is a very famous line near the end of the book, when he says, "You have seen how a man becomes a slave. You shall see how a slave became a man." He meant that slaves could regain their humanity through resistance to slavery, a very powerful statement during his own time.
Douglass is trying to show the dehumanizing effects of slavery on both the slave and the slaveowner. I think it is noteworthy that he spends some time writing about how the owning of another human being can degrade the owner. I believe Mrs. Auld is the person who changes from a caring person to a mean-spiriting abusive owner in Douglass' narrative. He attributes this to the harmful effect of slave-holding.
The book is actually very persuasive. By telling his life story in such a direct, beautiful and matter-of-fact way, Douglass really brings the cruelty of slavery to life. Even though he is not didactic, he is still very convincing. One of the most persuasive things about the book is the beauty and elegance of Douglass’s writing, despite his having been a slave.
The aim of this narrative is to help make people think that slavery was a bad system. Douglass was one of the leading figures in the American abolitionist movement. Therefore, it is not surprising that he would want to use his memoirs as a way to promote the idea of abolition. This is the main aim of the book.