The question of whether imagination can be reduced to other folk psychological states will turn, in part, on what we take those other states to be—on how we view their ontological status. There are very different views in philosophy and psychology concerning the nature of folk psychological states, ranging from eliminativism, to dispositionalism, to representationalsim. This chapter explains how those different ontological viewpoints bear on the project of explaining imagination. An important conclusion is that the explanations pursued in this book do not assume or require the existence of mental representations of any sort and thus should be of interest to theorists with quite different commitments concerning folk psychological ontology. However, in some cases, when assessing competing arguments, it will be essential to grasp the difference between “heavy-duty” (representationalist) views of folk psychological states and “light-duty” (dispositionalist) views.