In what way does this story support douglass's argument that slavery is dehumanizing to both slave and slaveholder?

(narrative of the life of frederick douglass)

One of the stories that demonstrate the dehumanization of both slave and slaveholder is the story of Sophia Auld. Douglass tells us that Mrs. Auld was a kind and fair woman. Moreover, she wanted to be just to her slaves. One of the things that Mrs. Auld believed was important was education. Therefore, she wanted to teach her slaves to read and write.

However, Mr. Auld believed this to be ridiculous, and he instructed his wife to act in a different way. Little by little, Mrs. Auld's kindness deteriorated, and what was left was cruelty and unfairness. This shows how slaveholders can be as affected and dehumanized as slaves due to this cruel system.

i wouldn't know because i've never read it, but going over it it looks interesting