 Jean-Jacques Rousseau (1712 - 1778), with his book "Emile, or On Education", introduced his pedagogic theory where the child should be brought up in harmony with nature.The child should be introduced to society only during the fourth stage of development, the age of moral self-worth (15 to 18 years of age).That way, the child enters society in an informed and self-reliable manner, with one's own judgment.