Abstract. Any researcher interested in defining the concept of quality of life faces a difficult epistemological task in terms of harmonizing a concept that seems by its very nature subjective and dispersed. Therefore, at present one can not speak of a universally accepted definition of quality of life but a series of different approaches to the concept based on hypothesis, assumptions and methods of analysis and research. From this viewpoint, the main aim of the present paper is to analyze two most known approaches on the concept of quality of life, so as to highlight the epistemological difficulties and challenges inherent to these approaches. Nevertheless, this paper does not seek definitive answers to the epistemological dilemmas, but set into the limelight these difficulties for further encouraging debate on these questions which might advance the state of research.

Keywords: utilitarianism; epistemology; capabilities; quality of life.