Socrates admits to Glaucon that the two of them had already discovered what justice is in the

city at the very beginning of their conversation. Justice in the city is “doing one’s own works-

provided that it comes to be in a certain way”, or more simply put; one person one job. (433b)

Socrates then continues on to justify his belief that the ‘one man, one job’ rule should be considered

in the city with great conviction.

Socrates first piece of evidence to support the inclusion of the ‘one man, one job’ rule as

justice in the city is that he believes that the ‘one man, one job’ rule is what is left over when the

other vices have been discovered. And that the ‘one man, one job’ rule “makes it possible for [the

other vices] to grow.”(433c)Because of the ‘one man, one job’ rule wisdom, courage, and moderation

can flourish and grow in the city. Next Socrates states that, the ‘one man, one job’ rule is the most

crucial virtue to the self-preservation of the city. Without the ‘one man, one job’ rule, the city will

not be able to sustain itself. Thus, Socrates argues it is more important that everyone does their job

then display wisdom, courage or moderation.

Secondly, Socrates explains what would occur if there was no justice present in the city. That

is, if people did not follow the ‘one man, one job’ rule. Socrates notes that if two men from the

working class switched jobs or both tried to also do each other’s job, the city would not be greatly

harmed. But if one the working class men try to become a guardian of the city or if “one of the

unworthy soldiers tries to enter that of the judges and guardians”, then the city will be damaged and

eventually brought to ruin.(434b)

Socrates gives one more piece of evidence to support the ‘one man, one job’ rule. However,

he mentions it at the very beginning, while establishing his city. The ‘one man, one job’ rule makes it

easier for the individuals to sustain themselves (rather than having to do every job themselves) and

“one person [will] do a better job … if he practices one.”(370b)