Full Idea
Each one of us in whom each part is doing its own work will himself be just and do his own. …So it is appropriate for the rational part to rule …and for the spirited part to obey.
Gist of Idea
If the parts of our soul do their correct work, we will be just people, and will act justly
Source
Plato (The Republic [c.371 BCE], 441d)
Book Reference
Plato: 'Complete Works', ed/tr. Cooper,John M. [Hackett 1997], p.1073
A Reaction
'Do his own' must mean play his own part in society correctly, because his internal faculties are also correctly focused on their role. So balancing the three parts in persons and society is not just an analogy, but one leads to the other. See 443e.
Related Idea
Idea 23561 People doing their jobs properly is the fourth cardinal virtue for a city [Plato]