Dissent is thought to play a valuable role in science, so that scientific communities ought to create opportunities for receiving critical feedback and take dissenting views seriously. There is concern, however, that some dissent does more harm than good. Dissent on climate change and evolutionary theory, for example, has confused the public, created doubt about existing consensus, derailed public policy, and forced scientists to devote resources to respond. Are there limits to the extent to which scientific communities have obligations to (...) seek and engage dissenting views? We consider the two main criteria that have been offered for what constitutes “normatively appropriate dissent” or the sort of dissent that ought to have the opportunity to be heard and taken seriously. Many have argued that dissenters must (1) engage in uptake of criticism against their own views and (2) share some standards for theory appraisal. We argue these criteria ultimately are unsuccessful. (shrink)