What is time? Don't ask me, and I know. Ask me, and I don't know. (St. Augustine) This post sketches, without defending, one theory of time.
On the B-Theory of time, real or objective time is exhausted by what J. M. E. McTaggart called the B-series, the series of times, events, and individuals ordered by the B-relations (earlier than, later than, simultaneous with). If the B-theory is correct, then our ordinary sense that events approach us from the future, arrive at the present, and then recede into the past is at best a mind-dependent phenomenon. For on the B-theory, there are no such irreducible monadic A-properties as futurity, presentness and pastness. There is just a manifold of tenselessly existing events ordered by the B-relations. Time does not pass or flow, let alone fly. There is no temporal becoming. My birth is not sinking into the past, becoming ever more past, nor is my death approaching from the future, getting closer and closer. Tempus fugit does not express a truth about reality. At best, it picks out a truth about our experience of reality.
If there is no temporal becoming in reality, then change is not a becoming different or a passing away or a coming into being. When a tomato ripens, it doee not become ripe: it simply is unripe at certain times and is ripe at certain later times. And when it cease to exist, it doesn't pass away: it simply is at certain times and is not at certain later times.
Employing a political metaphor, one could say that a B-theorist is an egalitarian about times and the events at times: they are all equal in point of reality. Accordingly, my blogging now is no more real (but also no less real) than Socrates' drinking the hemlock millenia ago. Nor is it more real than my death which, needless to say, lies in the future. Each time is present at itself, but no time is present, period. And each time (and the events at it) exists relative to itself, but no time exists absolutely.
This is not to say that the B-theorist does not have uses for 'past,' 'present,' and 'future.' He can speak with the vulgar while thinking with the learned. Thus a B-theorist can hold that an utterance at time t of 'E is past' expresses the fact that E is earlier than t. An old objection is that this does not capture the meaning of 'E is past.' For the fact that E is earlier than t, if true, is always true; while 'E is past' is true only after E. This difference in truth conditions shows a difference in meaning. The B-theorist can respond by saying that his concern is not with semantics but with ontology. His concern is with the reality, or rather the lack of reality, of tense, and not with the meanings of tensed sentences or sentences featuring A-expressions. The B-theorist can say that, regardless of meaning, what makes it true that E is past at t is that E is earlier than t, and that, in mind-independent reality, nothing else is needed to make 'E is past' uttered at t true.
Compare 'BV is hungry' and 'I am hungry' said by BV. The one is true if and only if the other is. But the two sentences differ in meaning. The first, if true, is true no matter who says it; but the second is true only if asserted by someone who is hungry. Despite the difference in meaning, what makes it true that I am hungry (assertively uttered by BV) is that BV is hungry. In sum, the B-theorist need not be committed to the insupportable contention that A-statements are translatable salva significatione into B-statements.
The B-theorist, then, denies that the present moment enjoys any temporal or existential privilege. Every
time is temporally present to itself such that no time is temporally present simpliciter. This temporal egalitarianism entails a decoupling of existence and temporal presentness. There just is no irreducible monadic property of temporal presentness; hence existence cannot be identified with it. To exist is to exist tenselessly. The B-theory excludes presentism according to which there is a genuine, irreducible, property of temporal presentness and existence is either identical or logically equivalent to this property. Presentism implies that only the temporally present is real or existent. If to exist is to exist now, then the past and future do not exist, not jusdt now (which is trivial) but at all.
Please note that the B-theory is incompatible not only with presentism, but with any theory that is committed to irreducible A-properties. Thus the B-theory rules out 'pastism,' the crazy theory that only the past exists and 'futurism,' the crazy view that only the future exists. It also rules out the sane view that only the past and the present exist, and the sane view that the past, present, and future exist.
Why be a B-theorist? McTaggart has a famous argument according to which the monadic A-properties lead to contradiction. We should examine that argument in a separate post.
Some thoughts (as nobody else had any).
Is there a historical connection between the idea that time is really a dimension of space, relativity and all that, and McTaggart's idea of the A and B series? From memory, Einsteinian ideas were being discussed in the late 19C before Einstein. By Poincare I think, who talks about Flatland and so on. In any case, there seems to be an obvious connection. If the time=space idea is correct, it follows that anti-presentism is a scientific position, not a metaphysical or linguistic one. I.e., just as all the points in space exist, so all the points of time exist. Therefore the view that the only things that exist are those which exist at the time of uttering 'now' is false, and an illusion. It would be an illusion comparable to the way that very young children imagine (I suppose) that the only things which exist are those in their immediate field of perception 'here'.
Thus in 'scientific' anti-presentism there is no special sense of 'exist', no tenseless sense vs tensed tense. Caesar really exists – in the normal, standard sense of 'exists', and the view that he no longer exists is a simple mistake, which science shows to be false, just as it showed us that the geocentric view was false. Superficially it is a more straightforward view. No worries about what we mean by 'exist' or 'present'. Everything in space-time exists. We can talk of things which 'exist now', but only in the sense that we talk of things 'existing here' (e.g. in my own house). 'Exists' is univocal.
How much of modern anti-presentism really borrows from this crude scientific anti-presentism? Is it just a dressing-up of it? Just as Wittgenstein's logical behaviourism could be viewed as a sophisticated (and somewhat obscure) dressing up of psychological behaviourism?
I suspect it is not so simple, though. On the scientific view, what sense can we make of a person such as Caesar? A space-time worm? Can a space-time worm be an 'individual'? Can it be happy or sad? Surely not, if Caesar was once happy and at another time sad. Can it be an emperor? Surely not. Can it die? No.
Posted by: edward | Tuesday, March 05, 2013 at 03:52 AM
Here is a link to an article on Henri Poincare, confirming his influence on the idea of time being dimension of space (as well his intriguing link to Picasso, thus inspiring a lot of dodgy art as well as dodgy philosophy.
Posted by: edward | Tuesday, March 05, 2013 at 08:38 AM
Ed,
The idea is not that "time is really a dimension of space," but that there is a four-dimensional continuum called space-time one dimension of which is time. Nevertheless, you are not entirely wrong since the B-theory could be said to 'spatialize' time with the idea that all times are equally real just as all places are equally real. Henri Bergson was one who complained of the spatialization of time.
McTaggart, I hope you know, is not a B-theorist. But part of his argument for the unreality of time, namely, that the A-series is contradictory, has been used by B-theorists to support their theory. See Hugh Mellor, Real Time. This is a contemporary classic in the philosophy of time. It is one of the books you have to read to be well-informed on this topic.
B-theorists needn't maintain that A-time is an "illusion," since they could maintain that it is mind-dependent.
As for space-time worms, the B-theory does comport well with the view that objects that persist through time persist by perduring rather than enduring (these are technical terms in the literature), that is, they persist by having different temporal parts at different times. But the issues here are extremely involved and would only muddy these troubled waters further. Same with any discussion of relativity physics and its denial of absolute simultaneity. Let's not go there!
You are mistaken if you think a 4D-ist can't accommodate Caesar's being happy at one time and sad at another. And what is your alternative?
First things first. I can't even get you to grasp what presentism is and how your original argument presupposes it.
The reason I posted on the B-theory was so that you would have a position that is anti-presentist for purposes of contrast.
Posted by: Bill Vallicella | Tuesday, March 05, 2013 at 10:41 AM
>>First things first. I can't even get you to grasp what presentism is and how your original argument presupposes it.
We need a clear definition of it first, as I pointed out. I looked at a few papers online (including Markosian's) and even they concede it is difficult to define it.
If someone is claiming that I don't grasp something, I don't think it's unreasonable to ask them to explain it!
Posted by: edward | Tuesday, March 05, 2013 at 01:05 PM