When modern economists use the notions of sympathy or empathy, they often claim that their ideas have their roots in Adam Smith's Theory of Moral Sentiments (1759/1976), while sometimes complaining that Smith fails to distinguish clearly enough between the two concepts. Recently, Philippe Fontaine (1997) has described various forms of sympathy and empathy, and has explored their respective roles in Smith's work. My objective in this paper is to argue that Smith's analysis of how people's sentiments impinge on one another involves a concept of fellow-feeling that is distinct from both sympathy and empathy. Unlike sympathy and empathy, fellow-feeling does not fit into the ontological framework of rational choice theory – which may explain why it tends to be overlooked by modern readers of Smith.