 With the rise of arguments for more fine-grained variability among presuppositions, inferences that we may have confidently called ’presuppositions’ have become harder to think of as forming a natural class. For some, the inconsistency in trigger behavior has fed into something of a presupposition identity crisis, a crisis dating at least as far back as Böer and Lycan’s (1976) description of semantic presupposition as a "myth". Karttunen (2016) reflects on the state of the field with an air of regret, saying that the "veritable zoo" of triggers that were lumped into the same presuppositional cage should never have been considered the same species in the first place. Ultimately, in order to either salvage a unified notion of presupposition, or else argue in a grand tradition (following e.g. Böer and Lycan 1976 or Karttunen and Peters 1977) for rejecting the possibility of a unified notion of presupposition, it has become pressing for linguists to understand how triggers and their inferences vary and why, fueling a trend in recent years towards systematic empirical work, looking for evidence of cross-linguistic variation, and developing methods for experimentally testing the predictions of different theories.