The true horror of slavery is shown in the way that blacks and whites can play together as children but then, as they gradually grow older, are forced to lead very different lives that remove them from each other. This is of course shown in the example of Nigel, who was the playmate of Rufus as a boy. However, as an adult, he obviously lives and moves in a very different kind of world. Although he does have a more important status as a house slave, he grows up with something more problematic for him, which is a desire for freedom and an appreciation of the inequality of his situation. When he attempts to run away, he is whipped mercilessly.
Although he realises that he is not going to be able to escape himself, I personally would argue that he never accepts slavery as it is. Even though he has learned his lesson very painfully, he still dreams of freedom and of a world where slavery does not exist. He says to Dana at one point, for example, that it is great having children, but "it's so hard to see them be slaves." This indicates that although Nigel does not try to openly oppose the institution of slavery yet again, he never really comfortably accepts his position as a slave.