Abstract

My analysis of temporal direction begins by establishing that time-reversal scenarios, scenarios in which the direction of time itself is reversed, whether locally or globally, are incoherent. Building on this conclusion, I argue that temporal directionality cannot be defined or explicated in terms of processes in time, such as the movements of celestial bodies, biological evolution or radioactive decay. In other words, while it is easy to imagine any process occurring in reverse, one cannot define the "earlier"/"later" relation by appeal to the stages of a process, for example, the consecutive stages of radioactive decay. The second section of the paper turns to a study of our firsthand experiences, and qualifies this result by arguing that experiences constitute the one class of events that cannot so much as be conceived as reversed in time. In the third section I suggested that our firsthand experiences figure as a standard by means of which temporal direction is given to us. I further argue that, despite the pivotal role played by experience in this scheme, we are fully warranted in being realists with respect to temporal directionality.