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 reject (...) two arguments from disagreement to a lack of progress, and spell out two accounts of progress on which progress is compatible with disagreements that persist or increase over time. However, we also argue that disagreement can undermine our ability to tell which developments are progressive (and to what degree). So, while disagreement can indeed be a threat to progress, the precise nature of the threat has not been appreciated. (shrink)