Plato · Philosophy
Plato’s theory that the soul has three parts - reason, spirit, and appetite - often in conflict, and that justice and well-being consist in their right harmony under the rule of reason.
Plato made a profound discovery about the human soul: that it is not a simple unity but is divided into parts that can conflict with one another. He identified three parts of the soul: reason (the rational part, which thinks, calculates, and seeks truth and the good); spirit (the spirited part - thumos - the seat of will, courage, anger, ambition, and the love of honour); and appetite (the appetitive part, the seat of bodily desires and appetites - hunger, thirst, lust, the desire for pleasure and material things). These three parts - reason, spirit, and appetite - can pull in different directions and conflict with one another, so that the soul is often divided against itself, torn between reason’s judgment of what is good, spirit’s passions of honour and anger, and appetite’s desires for pleasure and gratification.
Plato gave a vivid image of the divided soul in his dialogue Phaedrus: the soul as a charioteer driving two winged horses. The charioteer is reason - which must guide and control the horses, steering the soul toward the truth and the good. One horse is spirit - noble, obedient, and well-behaved, the ally of reason, responsive to command. The other horse is appetite - unruly, wild, and hard to control, pulling toward the gratification of bodily desires, resisting the charioteer’s guidance. The charioteer (reason) must control both horses - guiding the noble horse (spirit) and restraining the unruly horse (appetite) - steering the soul toward the truth and the good. This image vividly captures Plato’s conception of the divided soul: reason as the charioteer that must guide and control the spirited and appetitive parts (the horses), one noble and obedient, the other unruly and wild, steering the soul toward the good against the pull of unruly desire.
Plato’s theory of the tripartite soul grounds a profound conception of inner justice and psychic health: that the good life requires the right ordering and harmony of the soul, with reason ruling over spirit and appetite. The just and healthy soul is well-ordered - reason rules, spirit supports reason, appetite obeys, and the parts are in harmony, each performing its proper role. This inner harmony, under the rule of reason, is both justice in the soul (the right ordering of its parts) and health and well-being (the soul at peace with itself, well-ordered, flourishing). The unjust or unhealthy soul, by contrast, is disordered - the parts in conflict, or the lower parts (appetite, spirit) ruling over reason, the soul torn against itself, at war with itself, disordered and unhappy. Plato thus connects justice, health, and well-being in the soul: the just soul (reason ruling, parts in harmony) is healthy and flourishing; the unjust soul (parts in conflict, lower parts ruling) is unhealthy and unhappy. The good life requires the inner justice of the well-ordered soul - reason ruling, the parts in harmony - a conception that connects ethics, psychology, and well-being in a profound vision of the well-ordered soul.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Plato divided the soul into reason, spirit, and appetite, and made justice the harmony of these parts under reason. Explain the tripartite soul and inner justice in your own words.
Leads to Sigmund Freud.
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