Where does the study of the flow of time belong: physics, the cognitive sciences, philosophy, or somewhere else? Physicists and philosophers have set themselves up into two camps: those who believe there is genuine flow or becoming in the world and those who believe there is just a block of events. What had not been considered is whether the subjective feeling of flow of time is the same the world over, whether it could be tampered with by brain injury, or whether it is present at all developmental stages. Papers in this Annals volume lay out the problem, explain terms, and provide synopses of relevant ideas. There is considerable variation within and among the papers in relation to the subject areas (e.g., philosophy, physics, experimental psychology, developmental psychology, cognitive science, and linguistics) drawn upon to address this theme as well as the features of passage discussed (e.g., change, linearity, flow, and privileged perspective). However, despite this diversity, the papers can be broadly divided into two main groups: (1) those focusing on mathematical representations of passage and aspects of passage rooted in physics, and (2) those focusing on our capacities to experience and linguistically represent passage.