  The Extensional and Retentional models are the two principle forms of PT-realism. Proponents of the Cinematic model can subscribe to realism, but most do not. The task facing PT-antirealists is in one respect the easier of the two: unlike their realist counterparts, they are under no obligation to provide an intelligible account of how it is possible for our consciousness to embrace temporally extended phenomena. But in another respect their task is the more difficult. Antirealists are under an obligation to ‘save the (temporal) phenomena’: they need to supply a credible explanation as to why it seems so natural to say we perceive movement and change when, in actual fact, we do no such thing.