In his celebrated argument, McTaggart claimed that time is unreal because it involves temporal passage the movement of the Now along a series of moments and events and temporal passage is contradictory (, ). Detensers such as Robin Le Poidevin , D. H. Mellor , and myself (, ) find McTaggart's argument against temporal passage convincing, but they reject his conclusion that time is unreal. According to these philosophers, an ontology that recognizes temporal or B-relations (i.e. earlier than, later than and simultaneity) is sufficient to account for the reality that underlies our vague talk of the passage of time. Tensers such as J. R. Lucas , George Schlesinger , and Quentin Smith , believe that the tenseless view leaves out what is essential to our experience and the reality of time.