In Chapter 9, Douglass goes to work for Captain Thomas Auld. He uses a string of similes to describe the inconsistent demeanor of Thomas Auld toward those he enslaves:
At times, he spoke to his slaves with the firmness of Napoleon and the fury of a demon; at other times, he might well be mistaken for an inquirer who had lost his way.
Douglass compares Auld first to Napoleon (a French general who, several decades earlier, tried brashly to conquer vast swathes of the world), then to an angry demon, and at last to an "inquirer" who doesn't quite know where he is or what he is doing. These similes suggest that Auld is unclear about his motives and his goals. If one day he acts out of ambition, like Napoleon, the next he acts out of pure anger and evil. Yet another day he acts like he is trying to do a job someone else has given him, but he has no idea how to go about it or exactly who he is working for.
Douglass claims that because of this inconsistency, Thomas Auld is even less deserving of respect than most enslavers. It seems strange at first that Douglass would better respect an enslaver who is consistently righteous about his abuse. It is useful to keep in mind that Douglass's narrative is both the story of his life and a philosophical condemnation of the institution of slavery. Thomas Auld's wavering character represents the incoherent and uninspiring ideology behind the institution of slavery. Auld seems insecure about the fact that he is an enslaver by marriage: it is somewhat of an accident that he is in this position of authority. Auld's insecurity reveals the insecurity of the whole institution: it only has power because enough people recognize it as a legitimate institution. The way things go on the plantation has as much to do with Auld's mood as with anything else because the entire idea of white supremacy is not even consistently inspiring or convincing to the person who most benefits from it. In the figure of Auld, Douglass offers readers a mirror for the entire institution of slavery, which is not based on any tenable philosophy.
