"The power of blackness" is shown to be both a literal and symbolic element intrinsic to the themes in Benito Cereno. On its literal level, there is a "power of blackness" shown in how the slaves have overtaken the San Dominick. The power of the slaves represents one aspect of Melville's depiction of "blackness." People of color are shown to be vengeful and filled with a particular rage towards the conditions they face and the lives they lead. Their anger is representative of the "blackness" in their hearts, what Melville would call the "malign evil in man." This is something that Delano himself does not understand or accept in the exposition of the narrative. Yet, it becomes clear that this evil or blackness of heart does exist, as Melville suggests “in view of what humanity is capable, such a trait implies . . . more than ordinary quickness and accuracy of intellectual perception.” This reflection about the nature of "blackness" reveals not only the capacity of the slaves for evil, but also the condition that forced the slaves to embody such wrath. Enslavement, in general, is a reflection of what "humanity is capable." This can be seen in Cereno's response of "the negro" to Delano's question of “What has cast such a shadow upon you?” This "shadow" is "the power of blackness" from a symbolic and literal level.
From this, a distinct treatment of black slaves as characters in fiction becomes evident. Melville presents "blackness" in the form of the slave anger in a manner that represents vengeance. The slaves are depicted as a reminder of the capacity of human evil. This is embodied in Babo, the mastermind of the slave revolt. When taken to court, Babo is executed, with Melville describing the smile on his face even in his death reflective of the "hive of subtleties." The "power of blackness" reveals a capacity within people of color to embrace violence. Given the display of the capacity for evil that Melville wishes to explore, it can be seen that people of color and "the power of blackness" is one that embraces a condition of evil: "a tale of desperate men in the grip of a vengeful fury that those whom they hate cannot begin to understand." An implication of this depiction of people of color is that they are predisposed to "vengeful fury" that lies beyond comprehension. While Melville is speaking to a condition that is universal, the perception that the black slaves are cauldrons of evil and malevolence is something that emerges. It is in this light where Melville's treatment of black characters in fiction becomes evident and something to be discussed.