Douglass cultivates an ethos as a believable witness to slavery by drawing attention to himself as a frequent observer of cruelty. One instance occurs in Chapter 2, when he describes Mr. Severe:
Mr. Severe was rightly named: he was a cruel man. I have seen him whip a woman, causing the blood to run half an hour at the time; and this, too, in the midst of her crying children, pleading for their mother’s release.
Here, Douglass is careful to emphasize not just the fact of Mr. Severe's cruelty, but also the fact that he has seen him being cruel. Douglass also emphasized his status as an eyewitness in the previous chapter, in which he described what happened to Aunt Hester. From his hiding place in a closet, he actually saw the terrible beating she endured. His emotional account of what happened was not an exaggerated attempt to imagine on the page what brutal abuse might be like. Instead, it was a straightforward testimony of a true experience.
Douglass needed to convince readers that he was an authority on the subject of enslavement in the South. Indeed, Douglass wrote his narrative in part to convince Northerners that he truly had a personal history as an enslaved person to back up the claims he had been making about the need for abolition. Much of what went on on plantations was a secret before Douglass wrote about it because enslavers carefully kept information from getting out. Vigorous censorship was par-for-the-course in the antebellum South, and enslavers who controlled the vast majority of the wealth were careful not to allow very many schools to pop up. The literacy rate even among white people in the antebellum South was far lower than it was in the North. The slow spread of information in written form helped enslavers hide their shameful behavior and cultivate their reputations in the North as respectable neighbors. Without written evidence, they could claim that their detractors were slandering them. Douglass thus needed to work against an entire social infrastructure that was set up to encourage white Northerners to trust Southern enslavers and distrust anyone who spoke too badly of them. By not only describing his own direct experiences with violence, but also describing what it is like to watch others experience violence, Douglass becomes the Northern reader's eyes on the plantation. He is clear that he is not reporting hearsay, nor is he focusing exclusively on the ways he has been hurt. Rather, he is reporting direct observations of a brutal social system. Douglass thus convinced readers to trust him as an eyewitness to a world they had never seen.
In Chapter 10, Douglass fights Mr. Covey for a grueling two hours, and he wins. In his reflection on the fight, Douglass uses ethos to win patriotic white readers over to his side:
This battle with Mr. Covey was the turning-point in my career as a slave. [...] It was a glorious resurrection, from the tomb of slavery, to the heaven of freedom. My long-crushed spirit rose, cowardice departed, bold defiance took its place; and I now resolved that, however long I might remain a slave in form, the day had passed forever when I could be a slave in fact. I did not hesitate to let it be known of me, that the white man who expected to succeed in whipping, must also succeed in killing me.
Douglass is emphasizing that whatever his legal classification or "form" is (human vs. property), his spirit will not be crushed. "In fact," he writes, any attempt to classify him as less than human is invalid because his human spirit persists. Douglass's language here evokes American revolutionary rhetoric. He positions himself as someone with a "long-crushed spirit" that raises itself up to "defy" the "tomb of slavery." The Declaration of Independence and other documents and speeches from American revolutionaries had similarly used language of defiance against an oppressor. The idea of resurrection from a tomb, as if Douglass is Christ, aligns this defiance with good in the eyes of a highly Christian readership.
Douglass's patriotic language goes beyond winning over the sympathy of proud Christian Americans. He uses this language to break apart the idea that he or any person can be property in the first place. In the American legal system, the institution of slavery rested on John Locke's philosophical idea that enslavement did not violate a person's free will because an enslaved person could choose to die by suicide. Specifically, Locke argued, an enslaved person could choose to provoke an enslaver through defiance as a way of getting the enslaver to murder them. Douglass is pushing back on this logic. He is arguing that while an enslaver who "succeed[ed] in whipping" him into total submission would have to kill him, his defiance itself is about the kind of life he deserves, not about the right to die. For him, defiance is motivated by the belief that he does not deserve the abuse or the death that might result from it. Whereas Locke claimed that enslaved people were free to choose death, Douglass argues that enslaved people begin to be free when they realize that Locke is a liar, and the entire system is a con cheating them out of their fundamental rights.
