Pictures have always played a prominent role in philosophical speculation about the mind, but the concept of a picture has itself been the object of philosophical scrutiny only intermittently. As a matter of fact, it was studied most intensively in the course of a theological controversy in the Eastern Roman Empire, during the eighth century - which is a sufficient indication of its marginal place in the history of philosophy. Perhaps this is because pictures have never produced in us the theoretical paralysis which Augustine famously associated with time, but have on the contrary generally seemed too unproblematic to deserve much time from philosophers. Even today, after several decades of accumulating theory, philosophers with no stake in the matter are often impervious to its charm. I feel some sympathy for this attitude, because the task of explaining the nature of depiction is, I believe, one which calls for the refinement rather than refutation of our first thoughts about it. But a precise understanding of depiction is both a necessary prolegomenon to a significant part of aesthetics, and a useful prophylactic against confusion in the theory of the imagination. Besides, there is also the pleasure of the chase, which J. L. Austin nonchalantly appealed to many years before the Research Assessment Exercise was inaugurated.