According to a traditional view, there is no categorical difference between the phenomenology of perception and the phenomenology of imagination; the only difference is in degree (of intensity, resolution, etc.) and/or in accompanying beliefs. There is no categorical difference between what it is like to perceive a dog and what it is like to imagine a dog; the former is simply more vivid and/or is accompanied by the belief that a dog is really there. A sustained argument against this traditional view is prosecuted by Sartre, who develops an alternative according to which there is a categorical difference between the two phenomenologies. This paper draws on Sartre’s work in this area to develop a similar account of perception and imagination as categorically different.