The Nature of Mental Imagery: Beyond a Basic View

Many philosophers treat mental imagery as a kind of perceptual representation – it is either a perceptual state, or a representation of a perceptual state. In the sciences, writers point to mental imagery by way of a standard gloss – mental imagery is said to be (often, early) perceptual processing not directly caused by sensory stimuli (Kosslyn et al. 1995). Philosophers sometimes adopt this gloss, which I will call the basic view. Bence Nanay endorses it, and appeals to it in a number of places to argue that mental imagery plays various functional or explanatory roles, as well as to argue that some mental phenomena should be seen as forms of mental imagery. In places he goes even further, relying on this view of mental imagery to explain how mental imagery is a unified kind despite heterogeneous appearances, and using this view to support his claim that mental imagery is a natural kind. Nanay’s book – which is a both a useful introduction to the many ways that mental imagery appears in discussions across philosophy, neuroscience, and psychology, as well as an extended argument for the multi-faceted relevance of mental imagery to a range of projects in the philosophy of mind and psychology – thus also serves as a nice test case for whether this basic view of mental imagery is good enough to aid theorizing across philosophy and the sciences. I think not. I will illustrate why by looking at two areas. First, I will discuss Nanay’s argument regarding mental imagery and object files. Second, I will discuss an issue Nanay raises, regarding the relationship between mental and motor imagery. A longer discussion might look to many more areas – as already mentioned, Nanay’s book covers a wide range of mental phenomena – with the same lesson emerging. The nature of mental imagery cannot be fully understood without facing an array of choice points, many of which push us to make commitments beyond the basic view.