In his essay “Veridical Hallucination and Prosthetic Vision”, David Lewis uses a vignette called “The Censor” to demonstrate why a suitable pattern of counterfactual-dependence is required to for a subject to experience ‘genuine sight’. A subject’s experience of a scene has counterfactual dependence if, and only if, the subject is capable of distinguishing the scene from possible alternative scenes. This means that, for the subject, if the scene were different, the subject would have a different experience. Thus, the subject’s particular experience is counterfactually dependant on the particular scene being for the eyes. According to Lewis, if the subject’s experience of the scene lacks a suitable pattern of counterfactual dependence (meaning
