In this paper I will introduce a practical explication for the notion of expertise. At first, I motivate this attempt by taking a look on recent debates which display great disagreement about whether and how to define expertise in the first place. After that I will introduce the methodology of practical explications in the spirit of Edward Craig’s Knowledge and the state of nature along with some conditions of adequacy taken from ordinary and scientific language. This eventually culminates in the (...) respective explication of expertise according to which this term essentially refers to a certain kind of service-relation. This is why expertise should be considered as a predominantly social kind. This article will end up with a discussion of advantages and prima facie plausible objections against my account of expertise. (shrink)