Aristotle summed up the experience of Athens education and creatively divided the age of educated children into three stages: the first stage (from birth to 7 years old), the main task of this stage is to develop children's bodies, let children often participate in outdoor activities and develop good living habits; The second stage (7- 14 years old) is mainly about moral education for children, so that they can learn gymnastics and music and participate in various meaningful collective activities to purify the bad impulses and desires in their irrational souls and cultivate their good moral quality; The third stage (14-2 1 year), the main task of this stage is to educate children intellectually and develop their rational souls. Educators should let teenagers learn mathematics, grammar, poetry, rhetoric, ethics, philosophy and other disciplines.