Sympathy, the key element in Smith’s broader moral philosophy, involves more than “pity” or compassion,” by which “we feel for the misery of others” (18). It means “fellow-feeling with any passion whatever” (19). It does not necessarily mean that the impartial observer and the person involved share identical feelings. A witness to an extreme outburst of anger, for instance, is more likely to feel sympathy for the object of wrath than for the person who rages, at least until the reason for the anger is known. Likewise, the observer sympathizes with the person who suffers serious mental decline, for instance, not because the observer feels exactly what the afflicted person feels but because the observer knows what the afflicted person has lost.

Human beings crave sympathy, for “nothing pleases us more” than to find that others share “a fellow-feeling with all the emotions of our own breast” (22). Comedians tell jokes so the audience will join them in laughter. A reader finds satisfaction in sharing a book with someone who has never read it. Sympathy “enlivens joy and alleviates grief” (23). It is worth noting, however, that those afflicted by sorrow crave sympathy far more than those who feel happiness.