I argue that in epistemically well-designed scientific communities, scientists are united by mutual epistemic responsibilities, and epistemic responsibilities are understood not merely as epistemic but also as moral duties. Epistemic responsibilities can be understood as moral duties because they contribute to the well-being of other human beings by showing respect for them, especially in their capacity as knowers. A moral account of epistemically responsible behaviour is needed to supplement accounts that appeal to scientists’ self-interests or personal epistemic goals. This is (...) because neither the self-interest nor the epistemic account can always explain why it is rational for an individual scientist to be epistemically responsible. (shrink)