The Republic contains: (1) an implicit argument that slavery is unjust, (2) a bar against Greeks having Greek slaves that (3) allows barbarian slaves. The scholarship has failed to notice the first, that the second is a performative addressed to Greeks, and mistakes the third as explicit. Four passages are examined: (1) a catalogue of a Greek city’s social classes (433d1–5); (2) a bar against Greek slaves, asserting the continuation of barbarian slavery (469b5–71c3); (3) an assertion that the Best City can exist at any time and any place (499c7–d1); and (4) a passage asserting the injustice of enslavement (615a6–b6).