The approaches to the study of Languages for Special Purposes (LSP) stem from different scientific traditions and perspectives. The naming of the research object seems to be quite confusing at first, but it actually reveals the existence of two parallel views: one that is more concerned with lexical and morphosyntactic variations based on discipline restrictions; the other focusing on users’ communicative purposes to describe and explain particular language uses. This paper aims to explain this scientific divergence in terms of a different professional and scientific interest in the language(s) under scrutiny – that is, English and/or other languages – and the crucial impact that Swales's notion of discourse community has had on a more discourse-oriented approach.