The "philosopher-king" will be a ruler of a state. The wise person who accepts the power thrust upon him by the people who are wise enough to choose a good master. Plato describes these "philosopher kings" as "those who love the sight of truth" (Republic 475c) and supports the idea with the analogy of a captain and his ship or a doctor and his medicine. According to him, sailing and health are not things that everyone is qualified to practice by nature. A large part of the Republic then addresses how the educational system should be set up to produce these philosopher kings.
Work "The republic"