Sustainable development is popular, but also indeterminate concept, with many meanings and interpretations. This complex and vague idea seems more difficult to implement on the local basis then on the national level. It is therefore surprising that such an abstract concept has rather high mobilizing power. One of the explanations lies in its positive image. When one compares the “optimistic” concept of sustainability with the “pessimistic” concept of entropia, it is possible to hypothesize that its popularity is the result of its utopistic potential, i.e. its ability to visualize the reconciliation of the eternal fight between man (society), and nature. Comparing attitudes and statements with the actual behavior makes it possible to conclude that sustainability is just as popular as declaration, which is in strong contrast with the everyday reality. It is quite understandable that sustainability, as a radical concept, is difficult to implement in the real life. A lot has to be done in coordinating the measures on the local level in order to prevent shocks which would destabilize communities. But just the fact that the concept is provocative makes it effective in stimulating the discussion on numerous questions considering sound, sustainable development. This paper tries to structure the concept of sustainability in order to clarify its social potential.