The problem with social engineering is that the engineers don't know how to drive the train. More like a complicated machine than a single celled organism society is a collection of individuals. Human nature decrees that freedom of choice is an inherent part of our social DNA therefore a healthy society is one built upon the choices and decisions freely arrived upon by the individuals who make up the whole. It is the self-interest and self-direction of these choices which build into the productive life of a free society.