The distinction between an evaluative concept and its possible conceptions plays a prominent role in debates about constitutional interpretation. The main purpose of the paper is to raise some doubts about the linguistic assumptions that are employed in this debate, arguing that the semantic considerations underlying the concept versus conceptions distinction are much more problematic and inconclusive than generally assumed. The ways in which concepts are used in a speech act crucially depend on pragmatic determinants, and those, in turn, depend on the nature of the conversation. The paper shows that the debate about constitutional interpretation is better seen as a moral debate about the nature of the conversation that constitutional regimes should be taken to establish. The linguistic considerations in play depend on this moral issue; by themselves, they do not support any particular interpretative stance.