In this paper, I present two tools that help shed light on deep disagreements and their epistemological consequences. First, I argue that we are best off construing deep disagreements as disagreements over conflicting understandings of certain concepts. More specifically, I suggest that deep disagreements are disagreements over how to understand concepts that play what Michael Friedman calls a “constitutive” role for speakers. Second, I argue that we need a better understanding of what speakers are doing when they engage in deep (...) disagreements—what speech acts they are carrying out. I show that we are best off not reducing the relevant speech acts to more familiar speech act kinds, such as assertions or imperatives. I argue that when a speaker articulates an understanding of a concept, they are in part carrying out an act of stipulation. I provide an account of the pragmatics of stipulation and apply the account to examples of deep disagreement. Focusing on the stipulative dimension of deep disagreement opens up, in turn, a novel approach to defusing the epistemological challenges such disagreement seems to pose. (shrink)