Justice in a person and a city › The Tripartite Soul

Here comes the pivot that makes the *Republic* a work of moral psychology as much as political philosophy. Socrates argues that the soul has the same three-part structure as the city. In summary, Socrates distinguishes reason, spirit, and appetite in the soul, corresponding to the city's three groups (Book IV, 435b–441c). The *appetitive* part desires food, drink, sex, money: all the pleasures of the body. Plato groups many different desires under appetite, including necessary desires as well as unnecessary and lawless ones. It should not be treated as uniformly insatiable (Books VIII–IX, 558d–559c and 571a–572b). The *spirited* part is the seat of honor, anger, and ambition. It can express shame at an action judged bad and indignation at a perceived wrong. It can be trained to fight for what is noble and resist what is base. The *rational* part seeks truth and wisdom. It can understand the good, for life as a whole, beyond the moment. Its task is to judge what is good for the whole soul rather than simply satisfy the strongest current desire. ::: {.callout-note title="The Tripartite Soul"} Plato's model of the psyche divides it into three parts: *reason* (_logistikon_), which seeks truth and should rule; *spirit* (_thymos_), which seeks honor and should enforce reason's commands; and *appetite* (_epithymia_), which seeks bodily pleasure and should be governed by the other two. ::: Justice in the soul mirrors justice in the city. The soul is just when reason rules, spirit supports reason's rule, and appetite is kept in its proper place. The unjust soul is one where this hierarchy is inverted: where appetite dominates, or spirit rebels against reason, or the parts are at war with each other. Consider what this means for Glaucon's challenge. In Socrates' argument, an unjust person who escapes external punishment still suffers from disorder within the soul. Their soul is in chaos. In the tyrannical soul, appetites tyrannize reason. Socrates presents inner harmony as a condition of the happiness he is defending. The ring removes the ordinary risk of being caught; Socrates' response concerns what injustice does to the person acting unjustly.