Among the most animating debates in eighteenth-century British ethics was the debate over psychological egoism, the view that our most basic desires are self-interested. An important episode in that debate, less well known than it should be, was the exchange between Francis Hutcheson and John Clarke of Hull. In the early editions of his Inquiry into Virtue, Hutcheson argued ingeniously against psychological egoism; in his Foundation of Morality, Clarke argued ingeniously against Hutcheson’s arguments. Later, Hutcheson attempted new arguments against psychological egoism, designed to overcome Clarke’s objections. This article examines the exchange between these philosophers. Its conclusion, influenced partly by Clarke, is that psychological egoism withstands Hutcheson’s arguments. This is not to belittle those arguments—indeed, they are among the most resourceful and plausible of their kind. The fact that egoism withstands them is thus not a mere negative result, but a stimulus to consider carefully the ways in which progress in this area may be possible.