According to The B Theory, there are no genuine, unanalyzable A properties, and all talk that appears to be about A properties is really reducible to talk about B relations.

Does this B theorist, if they believe that tense has a subjective sense, and that the A series is contradictory, have to agree with the A theorist that:

[t]he verbal tenses of ordinary language (expressions like ‘it is the case that’, ‘it was the case that’, and ‘it will be the case that’) must be taken as primitive and unanalyzable

And can an expression made only of primitive expressions, like, let's suppose, tense and self existence (so: is is the case that I exist), actually never have any sense?

  • this will have a bounty if no-one replies... i'm trying to present an argument to someone on something and it hinges on this, which may also be linked to larger ideas about the nature of objectivity.
    – user6917
    Commented Mar 21, 2016 at 20:26
  • Why do you say that B theorists believe that tense has a subjective sense? Can you provide reference for this claim?
    – E...
    Commented Apr 29, 2016 at 21:04

2 Answers 2


I think that there is a sense in which a B theorist will likely agree that tensed expressions (is / was / will / etc) are primitive and unanalysable. A B theorist will typically not hold that tensed expressions are elimimable from ordinary language, that they can be actually dispensed with.

I will quote hereafter from an online article by D.H. Mellor from Cambridge U, a B theorist, author of the book Real Time on the philosophy of time.

As far as truth is concerned, Mellor holds that tensed expressions are analysable, along the following lines:

It is the case = at the time of this utterance,

It was the case = before the time of this utterance,

It will be the case = after the time of this utterance.

An ability to demonstrate at an utterance is granted here, supposedly without involving, however, an antecedent reference to "the present time".

What then does make A-series statements true? Again the answer is simple. For example, for any X, statements of the forms 'It is now X', 'X was last week' and 'X is due tomorrow' are made true respectively by being said at X, in the week after X, and the day before X is due. But those are all B-series facts, about when things happen and are said, regardless of which if any of those things and sayings are present - which is why these B-series facts imply no contradiction.

Mellor also holds, however, that tensed expressions are not replaceable when it comes to self knowledge. Like other indexicals ('here', 'now') and demonstratives ('this', 'I', 'you'), tensed expressions encapsulate self awareness in a way that cannot be emulated by B expressions. When Joe says on Wednesday "it will rain tomorrow" it carries the same truth content as if he said "it will rain on Thursday". But if Joe happens e.g. not to know that today is Wednesday, the two phrases are not epistemologically equivalent.

That for example was what caused me to go to London on 22 October 1999 in order to give the lecture at the Royal Institute of Philosophy . . . I went there then because I wanted to give that lecture, which I believed I was due to give there on that day. But for that belief to cause this action of mine it had . . . to be both a personal and an A-series belief. Believing that Hugh Mellor was due to speak in London on 22 October would not have been enough. That belief did not after all make anyone else go to London to speak, simply because no one else believed 'I am Hugh Mellor'. Nor would that belief have made me go to London then if I had forgotten who I was, and thereby ceased to believe that the speaker was not only Hugh Mellor but me. And similarly with the date. Wanting to be at the lecture, and believing it to be on 22 October, would not have taken anyone there on 22 October unless and until they also acquired the A-series belief 'Today is 22 October'.

  • hi, thanks so much for the reply, do you have a reference for it?
    – user6917
    Commented May 2, 2016 at 2:31
  • @math you're welcome. I will look for a reference. Commented May 2, 2016 at 17:20
  • @MATHEMETICIAN I've restructured the answer and added references. Commented May 3, 2016 at 20:06

From a mathematician's point of view, this all seems like a problem with parameterization and absent quantifiers. How does the 'A series' not just breakdown into the 'B series' with self-references and quantification?

"Two weeks in the future" is "Two weeks forward in time from the moment simultaneous with my completing this sentence." Then a single tense is a quantification over time. "It will be the case that X" is "There exists a moment subsequent to the completion of this sentence wherein X takes place." "X is happening" is "There exists a moment in the vicinity of this conversation in which X takes place".

So there seems to be a full analysis of A time in terms of B time, like the picture relativity makes of spacetime. Every event in an inertial frame of reference has a light-cone in four-dimensional space, and from the point of view of an observer of that event, events on that cone are simultaneous with it, those within the cone are in its future and those outside of it are in its past.

The A stream is a path through B time that can be taken, all relativised to the position and speed of a given observer. I have my A stream, and it does exist. It does not exist independent of an observer -- but nothing does. In the same way, unless we are moving parallel with one another, we are not going to agree on B timelines, either. Agreement upon simultaneity is only possible at very low relative speeds.

From that POV, I think this whole argument is rendered obsolete by the notion of special relativity. There is no universal A stream, but there is also no universal B stream, there is only unified A stream anchored to each individual observer and methods for triangulating those together into predictions of B events via computation.

The A and B timestreams are both constructions, and are fake, largely for the reason McTaggart would give. My future is in your past sometimes even if we will eventually come together and share a single present, so A is not real in any shared sense. Likewise, the time between two external events might be very different, depending upon how it is experienced, so B is not real in any shared sense. But there is an intermediate real object that is just unnatural and inconvenient to use directly.

  • we don't need the A series for indexicality?
    – user6917
    Commented Mar 30, 2016 at 9:24
  • I accept relativity. So ordering of events really depends on the observer. General indexicality of time is an illusion sustained by the fact we never move very fast relative to one another, nor do we live very far apart. Indexicality of spacetime is in neither A nor B series. In the end, Special Relativity agrees with both legs of McTaggart's argument and rejects his conclusion. A and B series are both fake, or at least very local, yet time as a dimension is real. It is just rather more complicated than we might wish.
    – user9166
    Commented Mar 30, 2016 at 17:47
  • ok, so GR has no A or B theory of time and that's all time is, and can still account for the subjective sense of tense? that's interesting, but i was asking about the B theorist, not GR :)
    – user6917
    Commented Apr 1, 2016 at 22:00
  • do you have anything to add which is more specific to the question? i'm not being ratty, i just wanted to work on this presentation thingy, so any help would be er helpful! i don't have library access either so...
    – user6917
    Commented Apr 3, 2016 at 12:09

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