In recent years, several philosophers have argued that their discipline makes no progress (or not enough in comparison to the ‘hard sciences’). A key argument for this pessimistic position appeals to the purported fact that philosophers widely and systematically disagree on most major philosophical issues. In this paper, we take a step back from the debate about progress in philosophy specifically and consider the general question: How (if at all) would disagreement within a discipline undermine that discipline's progress? We reconstruct (...) two distinct arguments from disagreement to a lack of progress, and argue that each rests on underscrutinized assumptions about the nature of progress. We then provide independent motivation to reject those assumptions. The upshot of these considerations is that widespread expert disagreement within a discipline is compatible with progress in that discipline. Indeed, progress can occur even as such disagreement increases. However, disagreement can undermine our ability to tell which developments are progressive (and to what degree). We conclude that while disagreement can indeed be a threat to progress (in philosophy and elsewhere), the precise nature of the threat has not been appreciated. (shrink)