The last decade saw a growing interest for hate speech and the ways in which language reflects and perpetuates discrimination, with two main focuses of interest: a linguistic-oriented question about how slurs encode evaluation on the one hand, and a philosophical and psychological question about the effects elicited by slurs. In this paper, I show how the two questions are deeply related by illustrating how a certain linguistic analysis of derogatory epithets – the presuppositional one – can shed light on non-linguistic issues, namely what effects the use of slurs produce, especially concerning discrimination. I present a presuppositional account of slurs (Section 2) and I show how such an analysis provides convincing explanations of other non-linguistic phenomena: in particular, I consider the ways in which slurs reflect and spread discrimination by illustrating how they work in conversation (Section 3). In Section 4, I argue that some features of slurs presented in Sections 2 and 3, namely the fact that they always target a category and the fact that the derogatory content that they convey is presented as not open to discussion, make slurs particularly dangerous tools. I conclude by briefly assessing the question as to how one should respond when exposed to the use of slurs.