This paper proposes an epistemological model based on cybernetic principles and activity theory to interpret two levels of problems that are intertwined in our social-economic system, namely the liveability and sustainability problems. In the first part of the paper, important principles and concepts from related fields of cybernetics and activity theory are introduced for later construction of a model. In the second part, a model is constructed based on the introduced concepts. To validate the proposed model, the current economic crisis is studied in the third part. An important contribution of the proposed model is a theoretical understanding of the two levels problems, and how to construct macro social-economical policies to avoid similar crisis in the future.