In his powerful interpretation of slavery in the American South, Eugene Genovese discusses the conception of the plantation as a “ family, white and black.” Like the domus in Rome, the planter's family encompassed his wife and children and his slaves, “and therein lay dangerous implications.” In suffering merciless beatings, the slaves “did not always fare much worse than the master's wife and children. From ancient to modern times we hear this theme. According to Roman legend, Manlius Torquatus beheaded his son, who had just returned victorious from combat, for breaking ranks.” Genovese quotes planters on the virtues of corporal punishment of children and slaves alike, concluding: “The slaveholders' vision of themselves as authoritarian fathers who presided over an extended and subservient family, white and black, grew up naturally in the process of founding plantations.” In the cultural matrix of the slave society, then, the categories of the master's slaves and of his children were assimilated, both subject to patriarchal authority enforced by violent coercion. As Genovese's reference to Manlius Torquatus shows, the stereotype of the Roman paterfamilias invites projection of such an assimilation back to Roman society, apparently confirmed by the similarities in the legal position of the slave and the filiusfamilias.

Despite the law, the Romans did not assimilate children and slaves in their reflections on the nature of authority. Cicero, following Greek philosophers, wrote that “different kinds of domination and subjection (et imperandi et serviendi) must be distinguished.” A father governs his children who follow out of readiness to obey (propter oboediendi facilitatem), but a master must “coerce and break (coercet et frangit) his slave” (Rep. 3.37).