 Murphy (2006) argues that the variety in mental illness requires us to explain psychiatric phenomena not by looking for stable regularities but by constructing exemplars. Murphy sees the exemplar as an imaginary patient who has the ideal textbook form—something like Thagard’s network, and the narrative it provides—of a disorder, and only that disorder, although the textbook needs to thought of as a statement of the final theory, and not any current work in psychiatry. As with zooming-in, the approach assumes that commonalities across patients will be revealed by inquiry. The idea is to model all the causes that contribute to a natural history so as to explore how they work together in different contexts to produce the various outcomes of interest, and then understand patients as idiosyncratic instances of the exemplar. When we explain a disease, we construct an exemplar and model it. But the causal structure that explains the exemplar resembles real world patients to varying degrees. So when we talk about individuals we explain their symptoms by identifying processes in the patient and showing how they resemble some part of the model. Godfrey-Smith (2006), following Giere, suggests that there may not be a helpful general treatment of these resemblance relations. They are not formal relations but the sort of comparisons between imaginary and real states of affairs that we all perform effortlessly. If there is a general theory, then, it is likely to be found not by philosophers but by cognitive scientists studying analogical thought (e.g. Hummel and Holyoak 2005). And because it is instrumental concerns that drive our search for explanations in psychiatry, as in medicine more generally, the clinically significant relations between disease, model and patient are likely to be highly context-specific; they will be determined in part by whether they offer opportunities for successful therapeutic interventions, which depend not just on how the world is arranged, but also on what our resources and opportunities are.