Abstract:A common objection to sense-datum theories of perception is that they cannot give an adequate account of the fact that introspection indicates that our sensory experiences are directed on, or are about, the mind-independent entities in the world around us, that our sense experience is transparent to the world. In this paper I argue that the main force of this claim is to point out an explanatory challenge to sensedatum theories. In the first part of the paper I explore the form of explanation that an intentional theory of perception can offer of this fact, and I contrast this with an alternative picture labelled naïve realism which can also accommodate and explain the fact of transparency. In the second part of the paper I explore the connection between sensory experience and sensory imagining, arguing that various features of sensory imagining support the hypothesis that in visualising a tree one imagines seeing a tree. In the final part of the paper I argue that the conclusion concerning sensory imagination presents an explanatory challenge for intentional theories of perception which parallels the challenge to sense-datum theories.How can there be debate about perceptual appearances, about how things seem to one? It is common to think that how things appear to one is something obvious to oneself-or at least that it should be obvious if one is suitably attentive to the question. So, one might ask, how can there be sustained debate about what is obvious? Where there is dispute, one should expect that the issue can be settled immediately by reflection on an appropriate example, or that at least one party to the debate is confused, or that the disputants are talking past each other about different experiences.Nevertheless, there is a long history of sustained disagreement about the nature of appearances. For there are many diverse theories of sense perception which seem to be opposed to each other: some are concerned to show a role for subjective entities or qualities in states of awareness; others are insistent This material has been presented in various forms to seminars in York, Lampeter, University College London, Canterbury, Sheffield, Glasgow, St. Andrew's, Oxford, Cambridge New York, and Nottingham. I am grateful for comments to the audiences on all of these occasions; to Ned Block, Paul Boghossian, Naomi Eilan, Keith Hossack, Jennifer Hornsby, Paul Noordhof, Mark Sainsbury, Scott Sturgeon and Jerry Valberg for extended discussion of these matters; to Tamar Gendler-Szabo, Owen Jones, Alan Millar, David Owens, Tom Pink, Paul Snowdon, Charles Travis, Alan Weir and Tim Williamson for responses and written comments and discussion on multiple drafts. I am grateful to the British Academy for research leave award during which the research for this paper was carried out.