Real Time II

D.H. Mellor

• Publisher: Routledge
• Year: 2002
• ISBN:
  9781134860265
• Edition: 1
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

Real Time II extends and evolves DH Mellor's classic exploration of the philosophy of time, Real Time. This new book answers such basic metaphysical questions about time as: how do past, present and future differ, how are time and space related, what is change, is time travel possible? His Real Time dominated the philosophy of time for fifteen years. Real TIme II will do the same for the next twenty. GET /english/edu/Studying_at_SU/History_of_Literature.html HTTP/1.0

1 Past, present and future

1 The question about time

The great question about time is what past, present and future are and how they differ from each other. The differences seem striking and profound. In the past is everything we have seen and done; in the future everything that has not yet happened or been done, none of which we can yet see; and in the present lie all our experiences, thoughts and actions. We plan for the future because we might affect it, while we know the past is out of reach. This is why it makes sense to think what to do tomorrow, but not what to have done yesterday: the time to think of that was the day before, when what is now yesterday was still future. And having thought what to do, we can only do it now: while the time for action is future we can only await it, and once it is past it is too late.

These ideas about past, present and future are central to our concept of time. But they are not self-evidently right. They want explanation, and while they lack it they will not want for sceptics. Modern physics especially has so altered our views of space and time that some would now set no metaphysical bounds to it. Thus even if no one now hopes to square the circle, some still think for example that we might affect or even revisit the past. To dispel such nonsense we must see more clearly what time is, and in particular what past, present and future are. To make that clear is the main object of this book.

To show what time is, I must start by assuming something about it, since even metaphysical bricks need some factual straw. And if in the end some of my assumptions will have to go, others will survive more or less intact. These of course I shall recommend as I go, since on their credibility that of my case will ultimately rest. But I shall not try to prove that everything I claim is either necessary or undeniable, since my aim is simply to tell the truth about time. Therefore, because necessity interests me mainly as a source of truth, and I do not claim to be infallible, I shall waste no time rebutting merely conceivable objections to what I have to say: doubt and disbelief are not worth trying to dispel unless they are both real and credible.

2 A-times

I shall start by introducing some useful terminology and stating some obvious facts. First, for the time being I shall mostly call all past, present or future entities, other than times, ‘events’. This is for brevity, and not because I think that events properly so-called (like World War II) do not differ from past, present or future facts (like France having a king), people (like David Hume) or things (like the Crystal Palace). Some of these differences I shall discuss in chapter 8.1, but until then I mean what I say about events to apply also to temporally located facts, people and things.

Then there is the obvious fact that pastness and futurity come by degrees. Past events are not all equally past, nor are future events all equally future. Eighteenth-century events were present before nineteenth-century ones, and that makes them more past. Thirtieth-century events will become present only after twenty-ninth-century ones, and that makes them more future. The time order of the world’s events is that in which they become present, thus forming what McTaggart (1908) called the ‘A series’. But his term, though now standard, is ambiguous. It may mean either the sequence of what I shall call ‘A-times’, defined by how much earlier or later they are than the present, or the sequences of events located at those times. Since, as we shall see, the difference matters, I shall call the former sequence the ‘A-time scale’, or ‘A-scale’, reserving ‘Aseries’ for the latter.

There is of course more to the A-scale than the mere order of A-times. Next Friday not only succeeds last Friday, it does so by seven days, i.e. by just as much as it precedes Friday-week. A-times thus have a measure that reflects how fast the events located at them succeed each other in the present, and also how long those events are present. Thus David Hume, who was present on earth for sixty-five years, now occupies sixty-five past years of the A-time scale. Other entities last less long: a wedding may be present for less than an hour. But neither people nor weddings are instantaneous: we can no more locate either at a single moment than we can locate them at a single spatial point.

I shall therefore not restrict A-times to A-moments, but will include intervals of them, whose order, inclusions and overlaps will be entailed by those of the moments they contain. Last year precedes this year because every A-moment in it precedes every A-moment in this year; next week includes next Monday because every A-moment in next Monday is also in next week; and so on.

Which A-times may we credit an event with at any given time? It is natural to give events any A-time that spans them, as when we say that a wedding happened last week or last year. But I shall also need to refer to the A-time of an event, and by this I shall mean its shortest A-time, the one whose end-points are the first and last A-moments at which the event was, is or will be present.

So much, for the time being, for my basic A-scale terminology. In adopting it, I am making no great claims for A-moments and intervals, except as a way of stating temporal facts about events. In particular, I do not take this terminology to entail that time could exist without events (although I think it could) or that all A-intervals must include shorter ones (although I think they do). Whether time needs events, or is infinitely divisible, are questions that my terminology need not and does not beg.

With these caveats, we may define past, present and future as follows. First, the past is the interval of A-moments open all the way from the remotest past up to, but not including, the present moment. Then other A-times are past if and only if the past includes them. Thus yesterday is past, as are last week and the first moment of last year. And any event is past while and only while its Atime—the shortest A-time that spans it—is past.

Similarly for the future. The future is the interval of A-moments open all the way to the remotest future and back to, but not including, the present moment. Other A-times, such as tomorrow, next week and the last moment of next year, are future because the future includes them; and any event is future while and only while its A-time is future.

The present is different. It may seem that, to make past, present and future incompatible, we should confine it to the present moment. But then many events, which last some time, would never be present. This problem has prompted the doctrine of the so-called ‘specious present’, which lets the present encroach a little on the past and the future. But by how much—a minute, a nanosecond? —and what then marks the present off from the non-present past and future? These questions have no good answer; but then they need none, since what is specious is the idea of a specious present, not the present itself.

The right way to define the present is this. In 1943, World War II stretched four years into the past and two years into the future. Yet it was certainly present then, as any combatant would then have testified. So its A-time, a six-year Ainterval including the present moment, should, despite its length, count as present. Similarly we should call any A-time ‘present’, however long it is, if and only if it includes the present moment. That makes this century as present an A-time as today or this moment. And so it should, since a centenarian whose A-time it is will obviously be present throughout it.

Present A-times so defined do indeed overlap and include past and future ones: on any 1 June which is a weekday, this week overlaps last month (May) and this year includes next month (July). Yet our definition respects the obvious incompatibility of past, present and future. It stops any A-time being both present and past, or present and future, by making present A-times include the present moment, and past and future ones exclude it. So nothing that has an A-time can ever be both present and past, or present and future. Its A-time at any given time either includes the present moment, making it present, or it does not, making it past or future.

This is how, while present events and A-times can be of any length, past, present and future remain incompatible properties: no event can have more than one of these temporal properties at once. (I scout the idea, to be dealt with later, that time goes round in a circle, so that what is future is also past.) Yet every event has each of these properties in turn, being first future, then present and then past. This is at once the essential and the most problematic feature of A-times, which any account of time must explain.

3 B-times

To explain how events move from future to past, we need another way of locating them in time. Dates provide such a way. In 2045, we can say that World War II ended a hundred years ago, which is an A-time. But we can also say that it ended in 1945, which is a date. Dates are independent of A-times, in the sense that any date can, and at some time will, have any equally long A-time. The year 2045, like the events in it, was once in the remote future, will eventually be in the remote past, and at some time in between is located at every year-long A-time.

So the fact that an event—an eclipse, say—occurs in 2045 says nothing about its A-time. The verbal tense I use to give a date may of course imply something about that: ‘The eclipse will happen in 2045’ implies that it, and 2045, are future, while ‘The eclipse happened in 2045’ implies that they are past. But we can easily omit this gratuitous A-scale information by using or inventing a form of verb which does not vary with A-time but can still be used with phrases like ‘in 2045’ to date events.

Dates thus form a sequence of times that are not A-times, because they are not defined by how much earlier or later they are than the present. This sequence, and that of the events which have them, McTaggart called the ‘B series’. As with his ‘A series’, I shall remove this ambiguity by calling the sequence of what I shall call ‘B-times’ the ‘B-time scale’, or ‘B-scale’, keeping ‘B-series’ for the sequence of events with those times. (By ‘times’ I shall, like most authors, generally mean B-times.)

How are B-times defined, if not by how much earlier or later they are than the present? The answer is that they are defined by how much earlier or later the events which have them are than each other. Thus in the Christian calendar 1800 is meant to be the year which contains the events that are between 1800 and 1801 years later than Christ’s birth. And the key point about this definition is this: these temporal relations between events never change, unlike their temporal relations to the present moment. For whereas the temporal distance between any event and the present moment is always changing—growing for past events, shrinking for future ones—that between events is always the same: any events that are ever n years apart are always n years apart. This is why the B-times of events, unlike their A-times, never change.

The relations of being simultaneous, or more or less earlier or later, are often thought to relate only events and hence only B-times. In fact, as I have already assumed, they relate A-times to...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Preface
• Introduction
• 1. Past, Present and Future
• 2. Truths and Truthmakers
• 3. Tokens and Times
• 4. The Presence of Experience
• 5. Time and Space
• 6. Thinking In Time
• 7. McTaggart’s Proof
• 8. Change
• 9. Events, Facts and Causation
• 10. Causation and Time
• 11. The Direction of Time
• 12. The Linearity of Time
• Bibliography