This study aims to investigate the concept of expertise in the light of Heidegger's theory of being.
The expertise was defined in comparison with ‘competency' and ‘knowledge'. Competency is the set of
key components what the expert in specific area should have, and expertise implies developmental
continuum from novice and expert. Competency can't be separated from the person, and personalized
knowledge indicates that the whole of knowledges or system of knowledges is embodied in the expert.
Sticking to this idea, Heidegger’s theory of being gives fundamental perspectives on expertise.
Belonging togetherness in theory of being criticizes an error of human thinking and let people take
central way, supporting with the three main concept of ‘Sorge’-taking care of myself, ‘Besorgen’-
concerning with tools, and ‘Fürsorge’-caring for others. In this study, the expertise in light of
Heidegger's theory of being is established as ‘ontology as the belonging together', ‘epistemology
as structure or system', ‘methodology as the phenomenological/hermeneutical', and ‘axiology as
care(Sorge), concern(Besorgen), caring for(Fürsorge)'. Expertise in light of Heidegger’s theory of being
does not exist in fixed and fixed ontological characteristics, but it is constantly changing in order to
reveal the possibility of oneself. In this respect, this study has the significant implication for alternative
understanding of expertise theoretically as well as the competency education practically.