This book by Professor Michelini offers a vision of the future from today's point of view and a strategy for dealing constructively with the critical technical and social issues associated with over-consumption. The first basic interest and merit of the book relies on returning up to a primary analysis of economy standards. In fact, four kinds of assets are at our disposal. Two are tangible and offer a limited resource: the natural capital i.e. in rough the materials extracted from the Earth; the human capital summarised as a force of work. Two are intangible and offer unlimited exploitation: the financial capital, resulting in an increasing of richness and allowing pertinent investments; at last, the technological capital, permitting an efficient using of the three others, savings, services of any kind and, partially, recovering of other used resources. And the question deepened by R Michelini deals with a balanced and efficient organisation and exploitation of the four assets, resulting, on the one hand, in the conservation and even an improvement of the natural capital, and, on the other hand, in a safety in matter of well-being growth i.e. in matter of sustainable growth.