Timelessness, metaphysics of

The metaphysics of timelessness focuses on the idea that time does not exist. To understand what this means, it is important to first gain a conceptual grip on what time is. Through an understanding of the concept of time, it is possible to differentiate between two types of timeless theory: Type-A theories, that deny the existence of time at fundamental and non-fundamental levels, and Type-B theories, that deny the existence of time at the fundamental level only. There are two broad motivations for timelessness. The first is a philosophical motivation, and is based on the dispensability of time for explaining physical reality. The second is a scientific argument, and is based on the elimination of time from theories of quantum gravitation. All timeless theories face two substantial problems. First: the observation problem. This is the problem of explaining how there could be any empirical evidence in favour of a timeless theory given that the process of gathering empirical evidence is, itself, a process that presupposes the existence of time. Second: the reconstruction project. This is the problem of recovering the various phenomena that seem to exist and that also seem to presuppose the existence of time, phenomena such as causation, change, consciousness and agency. The philosophical nature of both problems combined with the scientific basis for taking timelessness seriously makes the topic of timelessness one area in which philosophy and science come to inform one another, presenting exciting opportunities for collaborative research.