In Narrative of the Life of Frederick Douglass, an American Slave, Douglass makes the point that slavery harms not only the enslaved—it has negative effects on the slaveholders as well. The very act of keeping another human being in bondage and eliciting their obedience through violence warps a person’s character.

Early in his work, Douglass recounts the story of his Baltimore slaveholder, Mrs. Auld. New to being a slaveholder, she was a gentle woman who initially treated her slaves with kindness. Douglas goes as far as to say:

I was utterly astonished at her goodness. ... The meanest slave was put fully at ease in her presence, and none left without feeling better for having seen her. Her face was made of heavenly smiles, and her voice of tranquil music.

However, after gaining some experience in owning slaves, she cannot escape the detrimental effects this life has on her disposition.

That cheerful eye, under the influence of slavery, eventually became red with rage; that voice made all of sweet accord, changed to one of harsh and horrid discord; and that angelic face gave place to that of a demon.

Beyond its effects on the characters of individuals, Frederick Douglass claims that the institution of slavery has turned southern Christians into hypocrites who use their religion to justify horrific deeds:

the religion of the south is a mere covering for the most horrid crimes, a justifier of the most appalling barbarity, a sanctifier of the most hateful frauds, and a dark shelter, under which the darkest, foulest, grossest, and most infernal deeds of slaveholders find their strongest protection.

It amazes Douglass that people who claim to be Christians can act in so unchristian a manner. He describes one Baltimore slaveholder as “harder than stone” because of his egregious treatment of his slaves.

Directly opposite to us on Philpot-street, lived Mr. Thomas Hamilton. He owned two slaves ... of all the mangled and emaciated creatures I ever looked upon, these two were the most so. ... Mrs. Hamilton used to sit in a large chair in the middle of the room, with a heavy cowskin always by her side, and scare an hour passed during the day but was marked by the blood of one of these slaves.

Perhaps what Douglass finds the most horrifying example of slaveholder hypocrisy is the way some use the Bible as a justification for their brutality. Douglass uses the example of his cruel master Captain Auld, who experienced a religious conversion during a Methodist camp meeting:

I have said my master found religious sanction for his cruelty. ... I have seen him tie up a lame young woman, and whip her with a heavy cowskin upon her naked shoulders, causing the warm red blood to drip; and in justification of the bloody deed, he would quote this passage of Scripture—“He that knoweth his master’s will, and doeth it not, shall be beaten with many stripes.”

Frederick Douglass has significant evidence to prove his observation that “slavery is the enemy of both the slave and the slaveholder.”

Frederick Douglass presents several examples throughout his narrative of how slavery is not only injurious to slaves, but also to the slave owners themselves.  The first example arises as he explains his own parentage.  In his early years, he hardly saw his mother, a slave, because she was sent away to work; with his father, rumored to be the plantation owner, he had no relationship. 

Here, then, is the first injury: slavery allowed and even financially encouraged slave owners to give in to their lust and sexually abuse their slaves, then take no parental responsibility, allowing their own children to become slaves:

"The fact remains, in all its glaring odiousness, that slaveholders have ordained, and by law established, that the children of slave women shall in all cases follow the condition of their mothers; and this is done too obviously to administer to their own lusts, and make a gratification of their wicked desires profitable as well as pleasurable" (21)

At the same time, such acts were injurious to the wives of the slave owners, who often were aware of their husbands' adulterous acts.  Since they usually could not take out their hurt and anger on their husbands, they often directed it to the female slaves in question:

"Such slaves invariably suffer greater hardships, and have more to contend with, than others.  They are, in the first place, a constant offense to their mistress" (21)

Slave is also injurious to slave owners and overseers by nurturing their worst character traits and most violent tendencies, as Douglass experiences with both Mr. Gore and Mr. Covey:

"Mr. Gore was ... artful, cruel, and obdurate.  He was just the man for such a place, and it was just the place for such a man.  It afforded scope for the full exercise of all his powers, and he seemed to be perfectly at home in it.  He was one of those who could torture the slightest look, word, or gesture, on the part of the slave, into impudence, and would treat it accordingly" (37).

Later, Douglass reflects:

"(Gore's) savage barbarity was equalled only by the consummate coolness with which he committed the grossest and most savage deeds" (38).

When Douglass is sent to Baltimore, he meets his first truly kind white woman: Mrs. Auld.  She begins to teach him to read, smiles at him, and looks directly into his face.  Sadly, though, Douglass watches her character transform for the worse:

"But, alas! this kind heart had but a short time to remain such.  The fatal poison of irresponsible power was already in her hands, and soon commenced its infernal work.  That cheerful eye, under the influence of slavery, soon became red with rage; that voice, made all of sweet accord, changed to one of harsh and horrid discord; and that angelic face gave place to that of a demon" (47-48).

Ultimately, Douglas says:

"Slavery proved as injurious to her as it did to me.  When I went there, she was a pious, warm, and tender-hearted woman.... Slavery soon proved its ability to divest her of these heavenly qualities" (51-52).

Finally, Douglass believes that slavery is corrupting to the religious faith of slave owners, for "the religion of the south is a mere covering for the most horrid crimes, - a justifier of the most appalling barbarity, - a sanctifier of the most hateful frauds, - and a dark shelter under which the darkest, foulest, grossest, and most infernal deeds of slaveholders find the strongest protection" (86).