  So far as the perception of change is concerned, matters are by no means as clear-cut as Reid suggests. Endorsing the plausible-seeming Augustinian doctrine that consciousness is confined to the present point of time does not oblige one to reject the (equally plausible) claim that change and succession feature prominently in immediate experience. These claims are quite compatible with one another provided the experience of change occurs within the confines of the momentary present. Indeed, in the eyes of some – but not all – this confinement is a necessary precondition for contents to be experienced together. For according to one influential line of thinking regarding phenomenal unity, in order for contents to be experienced as unified, they must be presented simultaneously to a single momentary awareness.