Many have argued we have a moral obligation to assist others in need, but given the scope of global suffering, how far does this obligation extend? According to one traditional philosophical view, the obligation to help others is limited by our ability to help them, or by the principle that “ought implies can”. This view is primarily defended on the grounds that it is a core principle of commonsense moral psychology. This paper reviews findings from experimental philosophy in cognitive science demonstrating that “ought implies can” is rejected by moral psychology. Researchers find that moral obligations are ascribed to agents who cannot fulfill them, suggesting that moral requirements do sometimes extend beyond what we are able to do. This research furthers our understanding of moral obligation, identifies an important need for further cross-cultural work in moral psychology, and demonstrates a way in which scientific experimentation can be applied to improve upon the conceptual analysis of important philosophical concepts in normative ethics.