I develop an externalist perspective and analysis of the relatedness of loneliness and (harmful) alcohol use and the concept of loneliness. I depart from twenty qualitative interviews with people undergoing inpatient treatment for alcohol dependence. Both, loneliness and its relatedness to alocohol dependence turn out to be complex relational and interactional phenomena whose occurrence and dynamics depend on the social and situational conditions under which they arise. Despite huge variations in interviewees’ experiences of loneliness, they share a common phenomenological and (...) analytical structure. Loneliness arises when instances of social interaction fail to arrive at mutual understanding within a certain social context. Loneliness is neither reducible to individual experiences nor to distinctive characteristics of a person. Rather, it presents an evaluative and interactional phenomenon, a person’s awareness of his/her failure to establish mutual understanding with others in social interaction. The relatedness of alcohol dependence and loneliness is neither conceptual nor causal nor explainable by facts about the individuals concerned, but depends on the kind of loneliness involved and the function habitual ways of drinking alcohol have in a person’s everyday life and social environment. (shrink)