 We can more fully appreciate what is distinctive in Smith by comparing him with Hume. Smith’s thought circles around Hume’s: there is virtually nothing in either TMS or WN without some sort of source or anticipation in Hume, although there is also almost no respect in which Smith agrees entirely with Hume. Take their accounts of sympathy, for example. When Hume describes the workings of sympathy, he says that emotions “readily pass from one person to another,” like the motion of a string equally wound up with other strings, “communicat[ing] itself to the rest” (Hume 1739–40, p. 576; see also pp. 317, 605). He then explains that we obtain our idea of the other person’s feelings by inference—from the effects (smiles, frowns) or causes of those feelings. In both cases, the other’s feeling, once inferred, communicates itself directly to us, and our imaginations only intensify our idea of that feeling so as to raise it to the level of an impression (Hume 1739–40, pp. 576, 319–20). For Smith, by contrast, we place ourselves in the other’s situation and imagine what we would feel if we were there. Imagination is essential to the production even of the “idea” of another’s feelings, and sympathetic feelings are no longer ones that the other person need actually have. (Smith points out that this explains how we sympathize with some people, like gravely ill infants or the insane, who do not actually experience the suffering we feel on their behalf [TMS 12–13]). This account allows for us to judge other people’s feelings against the background of our sympathetic feelings for them. Sympathy is thus not just a way of sharing feelings with others; it also opens a gap between their feelings and ours. And that gap gives us a grip on the notion—crucial to Smith’s theory—that certain feelings are appropriate to a situation, while others are not.