Introduction: seeing time

Ineluctable modality of the visible.

Joyce, Ulysses, 45

1.1 VISION: FROM IMPLICIT TO EXPLICIT TIME

Something we call "time" permeates everything that happens and everything we do. Events, processes, experiences, actions, and activities take place at particular times and occupy stretches of time, are composed of constituents that also occupy time, have a temporal order, and are otherwise related in time to each other. Time also seems to be intimated to us from within our own bodies, incarnate in what we may think of anachronistically as "proto-clocks" formed out of recurrent and cyclical events within the cycle of our days: waking and sleeping, rising and settling down, the patterns of hunger and thirst, and, more prominently, the rhythms of breathing and the heartbeat and the tick-tock of walking. But this inherent time of the body does not amount to fully explicit time, even less "timing", since it is not clearly offset from the changes in which it is expressed. The rhythm of my heart is, even when it is noticed, interwoven with the activities or emotions that cause the organ to beat faster and more thickly. The temporality of what is going on is consequently for the most part implicit, woven into what is experienced.

Time as something "in itself", that is available ultimately to be clocked, is most clearly developed in relation to our consciousness of things outside of our bodies, "out there". The immediate presentation of the world around us, unfolding in or over time, is the first step towards opening up the present to an ever more remote past, an ever more distant future. Eventually we locate ourselves in a common past and future flanking a communal present – in a remembered social history and anticipated social future we share with our fellow humans, and a natural history we share with all beings. Ultimately, we come to be aware of our lives as brief episodes in a story that stretches from pre-history to post-history, from the Big Bang to the Big Crunch.

Foremost among the senses that yield an explicit sense of time, though by no means exclusive, is vision. While it is obvious that vision is a revelation of explicit space it is less easy to appreciate its importance in the revelation of explicit time. Even so, it is the case; and it is of fundamental significance not only for the metaphysics of everyday life, but also for the development of the physical sciences that have challenged that metaphysics, and for the relationship between the two. The key role of vision in making time explicit, which predisposes us to spatialize it, lies at the root of the intellectual, cognitive and cultural developments that are examined critically in this book.

Before I argue for the privileged relationship between vision and explicit time, I want to pre-empt a serious misunderstanding. The world we humans live in is not merely a sensory bubble, revealed to individual viewpoints. It is the product of the joint labour of all of us – our predecessors and our contemporaries. Each of us acquires the world in which we live our lives largely "off the shelf" rather than constructing it directly out of sense experience. World-acquisition is overwhelmingly dependent on sign systems, the most elaborate of which (though not by any means the earliest or the most fundamental) is language as conventionally understood. The temporally deep world extends far beyond that which is revealed to vision; and it is available to anyone who can participate in the community of shared consciousness that is humanity. And this of course includes individuals who are congenitally blind. I make this perhaps rather obvious point in order to head off the objection that the initial importance of vision in humanity's development of the intuition of temporal depth would preclude those without sight from full participation in a world saturated in explicit time – something that is manifestly untrue. In some respects, people who have congenital blindness bypass the ground floor of explicit time as presented through vision (as I shall describe) and proceed directly to the higher levels. What is more, they draw on the explicit time made available through other senses – touch, hearing, and the experience of kinesis – which are overshadowed in the experience of the sighted for whom the visual sense dominates in explicit time.

I want, also, to pre-empt another potential misunderstanding. What I will describe is how we come to perceive "the passage of time" as it is conventionally understood. I shall argue in §2.2.3 that there is no such thing as the passage of time. The tendency to use dynamic metaphors is rooted in the fact that time becomes explicit most clearly through a particular, universal form of change, namely motion. Time made explicit through motion is liable to be thought of as being itself in, or a kind of, motion; hence talk of "the flow" or "passage of time".

Let us now examine the special relationship between vision and explicit time. Consider an object moving across your visual field. It occupies a succession of positions, P1, P2, P3, etc., at times t1, t2, t3, etc. The object survives the move, essentially unchanged. But, more importantly, the positions occupied by the object outlast the period during which they are occupied by the object. P1 (composed of the matter that surrounds the object at t1) is still there at t2 when the object has moved on to P2. And P3, a position the object has not yet reached, is also present and visible at t, when the object is at P2. Because all three positions are co-present in my gaze, I can see the past and future locations of the object as well as its present position. By virtue of being the past position of the object, P1 stands for its past when the object reaches P2. And by virtue of already being in place when the object is at P2, P3 represents the future of the object. More generally, we can say that places typically outlast the events (such as the transit of an object) that have occurred in them; they provide a constant background against which a succession of events can be bound together into the event of succession and the object, which can occupy only one point at one time, can nevertheless trace a trajectory that has both spatial extensity and temporal depth. The position – which is the surviving relatum of the relationship between the object and a position, or of the complex object-in-a-position – curates the past of the object.

1.2 THE HEGEMONY OF VISION IN EXPLICIT TIME SENSE

It hardly needs saying that vision is not the exclusive domain of explicit time...