Introduction. Although, it is widely used, there is no consensus among researchers in defining the concept of sustainability The various scientific debates available in the literature consider that the concept of sustainability should be approached in an integrated manner, which involves the maintenance and the improvement of the welfare at the economic, environmental and social level, taking into account both the importance of the processes and the output of the system.
Aim of the study. The paper aims to clarify the concept of sustainability through an examination of different opinions and controversies existing in the literature regarding this concept. Also, the paper presents the concept of sustainability analyzed from the perspective of system and proposes a definition of sustainability by exposing the sufficient logical conditions for a system to be qualified as a sustainable system. Are analyzed concepts such as: logically vivid system, autopoiesis, weak sustainability, strong sustainability, sustainable development.
Keywords: system, sustainability, sustainable development, logical conditions
JEL Classification: A10, O17, P00