The present chapter focuses on the role of imagery in scientific reasoning. The main questions to be considered, are: 1) what role does visualisation play in scientific reasoning? and hence 2) what epistemic credentials, if any, does visualising have in scientific reasoning? In addressing these issues, we will look at fictional accounts of scientific models, the transparency of imagining, and the nature of epistemic and aesthetic feelings. In brief, two key moves need to be made to secure the epistemic standing of sensory imagining in science. First, in exploring the differences between the transparency of perceptual and imaginative experiences, we need a proper appraisal of the relationship between sensory imagining and affect, and in particular the affective feelings that are manifestations of aesthetic experience. Second, we need to focus our attention on the notion of understanding, rather than truth or knowledge.