A fictional character created by Socrates, Diotima is described by him to be a woman who was wise about many things. Rather than tell a speech like the others, Socrates tells Agathon’s guests a dialogue he had with this woman of Manitea many years ago. The dialogue began primarily with her questioning him, then turning into her giving a speech on Love. She defines who Love is and explains that the object of love was giving birth in Beauty to true virtue, the ultimate act of Love, which is fulfilled upon completing the “Ladder of Love” she describes. In the most serious speech of the book, the reader is distanced from the content with an added layer of indirect narration.
Socrates then proceeds to find the corresponding four virtues in the individual (434d). Socrates defends the analogy of the city and the individual (435a-b) and proceeds to distinguish three analogous parts in the soul with their natural functions (436b). By using instances of psychological conflict, he distinguishes the function of the rational part from that of the appetitive part of the soul (439a). Then he distinguishes the function of the spirited part from the functions of the two other parts (439e-440e). The function of the rational part is thinking, that of the spirited part the experience of emotions, and that of the appetitive part the pursuit of bodily desires. Socrates explains the virtues of the individual’s soul and how they correspond to the virtues of the city (441c-442d). Socrates points out that one is just when each of the three parts of the soul performs its function (442d). Justice is a natural balance of the soul’s parts and injustice is an imbalance of the parts of the soul (444e). Socrates is now ready to answer the question of whether justice is more profitable than injustice that goes unpunished (444e-445a). To do so he will need to examine the various unjust political regimes and the corresponding unjust individuals in each (445c-e).