The character of Moses in The Known World is hugely significant, as he acts as a framing device for the novel and its various themes.

He represents, to a certain extent, the confusion of racial identity epitomized by a black man owning slaves in the antebellum South. Upon being bought by Henry Townsend, Moses ponders the puzzling fact that ". . . a black man, two shades darker than himself . . ." should now be his new lord and master. The situation of a white man owning slaves, though of course profoundly unjust to Moses and all other slaves, does at least have a certain logic to it given the widely shared racial prejudices of the time. A former slave doing the exact same thing goes one stage further, and upsets a balance of forces which causes Moses to wonder whether God is any longer attending to business.

Throughout the story, Moses moves readily between the worlds of (relative) freedom and slavery, separate spheres whose boundaries often become blurred. In due course, he becomes an overseer on Henry's plantation, and exercises an often harsh and violent level of control over the other slaves—including his own wife Priscilla. But despite his position of relative superiority he never truly feels free, at least not in the world of mid 19th-century Virginia.

Moses experiences some measure of freedom by occasionally retreating into the world of nature. Here he is a man, not a slave or an overseer. In tasting the earth and drinking the rainwater he savors a taste of nature's liberty, which gives him a brief respite from the brutal social world he is forced to inhabit.

But although nature provides Moses with a tantalizing glimpse of freedom, he can never truly escape. His whole mindset has been so conditioned and distorted by his experience in slavery that beyond the forest lies a strange land of darkness and uncertainty. And so his desperate attempt at escape ultimately ends in recapture and agonizing pain.

The abiding message of The Known World is that freedom and slavery can often be ambiguous terms. This ambiguity is starkly illustrated by the character of Moses, who shows us the extent to which we are all creatures of the time in which we were born and the world into which we have been thrown.

Set in 1855 Virginia, the novel "The Known World" is an unusual story of slavery in America because the slaveowner is a black man. Henry Townsend was born into slavery himself, but his father worked hard to win his freedom. When Henry does establish his own plantation, he models himself on his former master, William Robbins, whom Henry respects and has grown very close to.

Moses is the first slave Henry chooses, and he becomes overseer of the plantation. In that position, he is second only to the plantation owner in power, and Moses uses that power to his own benefit. He is cruel to the other slaves. His importance to the story is that even though he is himself a slave, he treats the other slaves the same way a white overseer might treat them. Put in a position of power, even a slave takes advantage of other slaves.