Aristotle (Politics 1255b) says of the slave that he is “part of the master – he is, as it were, a part of the body, alive yet separated from it.” The symbiosis of master and slave is the subject of this chapter, a paradoxical symbiosis between the master and his “separate part” that expresses itself in complementarities, reversals and appropriations. This symbiosis, and the attendant ironies of domination, are central to the European tradition of literature about servants, passing from the ancient literature into Cervantes' Sancho Panza and Don Quixote, Diderot's Jacques and his master, Wodehouse's Jeeves and Wooster and a host of other pairs; it is epitomized by Hegel's discussion of the dialectic of slave and master in the Phenomenology.

Aristotle might have added that the slave is part of the master's mind as well as his body, both an unruly part of the master's knowledge of himself and, by virtue of the huge difference in status, a parodic version of the master's knowledge of the world. For the slaves in this chapter (with one exception) it is manifestly not true that “a slave does not know his master's business” (John 15.15). Some slaves, of course, were deeply involved in their masters' business, performing crucial tasks as secretary and amanuensis. Cicero's Tiro is a famous example. Just how indispensable such a slave could become is graphically shown by the letters (collected in ad Fam.16) that Cicero wrote to Tiro, whom he freed in 53, and the master's love for his (now ex-) slave is vividly expressed in the letters he wrote when Tiro was dangerously ill with malaria.