Abstract
The aristocratic city described in Plato's _Republic_ is a hypothetical city, as opposed to a city that exists. But in the _Republic_, Socrates and his interlocutors argue that this city is practicable, meaning, roughly, that it *could* exist. I contend that their argument for that claim is essential to their argument that the city is just. In other words, I maintain that the first argument has to succeed in order for the second argument to succeed: in order to show that the city is just, Socrates and his interlocutors need to demonstrate that it is practicable or, at least, that it could be approximated closely enough by an existing city.