In Plato’s mind, education was a state concern. Teachers should be chosen by the government and managed by a special set of magistrates. Students would advance through several stages of learning: kindergarten before age seven, primary school where they would learn gymnastics, music, and mathematics until age ten, and then secondary school from age ten to eighteen. After secondary school, the brightest of the students would begin ten more years of training with advanced studies in all areas. When those had been mastered, philosophical studies could begin.
Unfortunately, Plato’s system turned out to be too complicated for the practically minded Athenians. Frustration with the government’s unwillingness to embrace his model is reflected in some of the late dialogs which show bitter resignation.