From the text:
The everyday activity of slaves reproduces slavery. Through their daily activities, slaves do not merely reproduce themselves and their masters physically; they also reproduce the instruments with which the master represses them, and their own habits of submission to the master’s authority. To men who live in a slave society, the master-slave relation seems like a natural and eternal relation. However, men are not born masters or slaves. Slavery is a specific social form, and men submit to it only in very particular material and historical conditions.