Rousseau demonstrated that education must "belong to nature" from the various influences of children. He said that everyone is trained by natural education, food education and artificial education. Only the perfect combination of the three kinds of education can achieve the expected goal. However, the manpower of natural education is uncontrollable, so it is impossible to make natural education close to physical education and artificial education, and only the latter two tend to be consistent with natural education. Therefore, education "belongs to nature", that is, good and effective education can be based on natural education.