“Born of a violent usurpation, slavery would—and perhaps could only—die in the same bloody warfare.” 

Berlin emphasizes struggle and negotiation throughout the entire text. For centuries, slaveowners won increasingly authoritarian rule over slaves, but slaves resisted all the while. Because the institution grew to be so central to pockets of American economy and culture, only resistance in the form of violent warfare could break it apart. 

Yet even when their power was reduced to a mere trifle, slaves still had enough to threaten their owners—a last card, which, as their owners well understood, they might play at any time.” 

One of the most important themes in the book is slave resistance and the related concept of slave agency. Slaves acted; they were not merely acted upon. Slaves managed different types of negotiations at different historical moments. Sometimes, their negotiations had the potential to result in freedom for an individual or an entire family. At other moments, a successful negotiation might involve selling married slaves to the same new owner. Always, slaveowners had to entertain their slaves’ demands or risk slave revolt by not compromising. Because slaveowners feared insurrections so much, and because they relied on their slaves to maintain their wealth, they continually made concessions and compromised with slave demands. 

“The slaves’ history—like all human history—was made not only by what was done to them but also by what they did for themselves.” 

A constant throughout the monograph is Berlin’s exposition of slave agency in the face of extreme oppression. This means that he reveals how slaves directed the course of their own lives even within significant structural confines.