What does Douglass mean by slavery dehumanizing both the slave and the slavehold

What does Douglass mean by slavery dehumanizing both the slave and the slavehold

What does Douglass mean by slavery dehumanizing both the slave and the slaveholder?
Give examples (with page numbers) from his Narrative of both.
Your only source is this textbook
Douglass: Narrative Chap. I-VII & XI (pp. B1077-1095 & B1122-1129)
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