a1 Australian National University
Much debate in contemporary metaphysics of time has centred on whether or not tense is essential to the understanding of a temporal reality. The rival positions in this debate are associated with two very different pictures of the relationship between time and existence. Those who argue for the dispensability of tense see the phenomenon of tense as an epistemological accretion which infects our perception of the world but is in no way essential to a complete description of reality. With respect to existence, things past and future are supposed to be on an equal footing with things present. Thus the Quinean ‘time slice’ ontology, which sees the world as a four-dimensional entity in space-time, repudiates any ontological significance to the differences between past, present and future. For the Quinean, what differences we see between past, present and future existents pertain to our limited mode of access to reality. In a perception which grasped the world as it really is tense differences would have no place. In this respect the Quinean position resembles Spinoza's claim in the Ethics that in so far as the mind conceives a thing under the dictates of reason it is affected equally, whether the idea be of a thing future, past or present.