Abstract
In the past economics ignored the limits of natural resources. In the last few years a new methodological approach comes into economics improving the comprehension of the economic phenomena linked to the satisfaction of the needs of modern man that basic considers the quality of life. The objective of this research is to define the theoretical and methodological aspects of a sustainable economy pointing out the reasons and the grounds on which to build an environmental policy. This one has to consider either the economic matters or the environmental sensitivity of people. This research is divided into three parts. The first one defines the outlines of the sustainable economy and its characteristic features. The second one emphasizes the necessity of replacing the concept of sustainable development instead of development and growth. At last, the third part identifies the basic lines into which the environmental policy has to be realized defining its reasons, its foundations and its valuation systems.